China lymphoma diagnosis and treatment guideline (2026 edition)

The American Society of Colon and Rectal Surgeons (ASCRS) is dedicated to ensuring high-quality patient care by advancing the science and prevention and management of disorders and diseases of the colon, rectum, and anus. The Clinical Practice Guidelines Committee is composed of ASCRS members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus and develop clinical practice guidelines based on the best available evidence. Although not proscriptive, these guidelines provide information on which decisions can be made and do not dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information on the management of the conditions addressed by the topics covered in these guidelines. These guidelines should not be deemed inclusive of all proper methods of care nor exclusive of methods of care reasonably directed toward obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician considering all the circumstances presented by the individual patient. STATEMENT OF THE PROBLEM A generally accepted explanation for the cause of anorectal abscess and fistula-in-ano is that an abscess results from obstruction of an anal gland and that a fistula is caused by chronic infection and epithelialization of the abscess drainage tract.1–4 Anorectal abscesses are described by the anatomic space in which they develop; ischiorectal (also called ischioanal) abscesses are the most common followed by intersphincteric, supralevator, and submucosal locations.5–8 Anorectal abscess occurs more often in males than females, and although an abscess may develop at any age, the peak incidence is among 20- to 40-year-olds.4,8–12 In general, an abscess is treated with prompt incision and drainage.4,6,10,13 The diagnosis and treatment of necrotizing soft tissue infections and Fournier’s gangrene are beyond the scope of this guideline. Fistula-in-ano is an epithelialized tract that connects the perianal skin with the anal canal. In patients with an anorectal abscess, 30% to 70% present with a concomitant fistula-in-ano, and, of those who do not, approximately 30% to 50% will ultimately be diagnosed with a fistula in the months to years after abscess drainage.2,5,8–10,13–16 Although an anorectal abscess is described by the anatomic space in which it forms, a fistula-in-ano is classified in terms of its relationship with the internal and external anal sphincters (eg, the Parks classification; Table 1).16 In general, intersphincteric and transsphincteric fistulas are more frequently encountered than suprasphincteric, extrasphincteric, and submucosal tract locations.9,17–19 Anal fistulas may also be classified as “simple” or “complex.”20,21 Complex anal fistulas include transsphincteric fistulas that involve greater than 30% of the external sphincter, suprasphincteric, extrasphincteric, or horseshoe fistulas and anal fistulas associated with IBD, radiation, malignancy, preexisting fecal incontinence, or chronic diarrhea.20–22 Recurrent or branching fistulas may also be described as complex. Given the attenuated nature of the anterior sphincter in women, anterior fistulas deserve special consideration and may also be considered complex. Simple anal fistulas have none of these complex features and, in general, include intersphincteric and low transsphincteric fistulas that involve less than 30% of the external sphincter. TABLE 1. - Parks classification of fistula-in-ano Fistula type Description Submucosal Superficial fistula tract. Does not involve any sphincter muscle. Intersphincteric Crosses the internal sphincter and then has a tract to the perianal skin. Does not involve any external anal sphincter muscle. Transsphincteric Tracks from the internal opening at the dentate line via the internal and external anal sphincters and then terminates in the perianal skin or perineum. Suprasphincteric Courses superiorly into the intersphincteric space over the top of the puborectalis muscle and then descends through the iliococcygeus muscle into the ischiorectal fossa and into the perianal skin. Extrasphincteric Passes from the perineal skin through the ischiorectal fossa and levator muscles and then into the rectum and lies completely outside the external sphincter complex. Adapted from Parks et al.16 Distinct from cryptoglandular processes, anorectal abscess and fistula-in-ano can be manifestations of Crohn’s disease. Among patients with Crohn’s disease, fistula-in-ano has an incidence rate of 10% to 20% in population-based studies and 50% in longitudinal studies; meanwhile, nearly 80% of patients with Crohn’s disease who were cared for at tertiary referral centers may have a history of fistula-in-ano.23,24 In Crohn’s disease, anorectal abscesses and fistulas seem to result from penetrating inflammation rather than from infection of an anorectal gland.25 Patients with fistulas related to Crohn’s disease are typically managed with a multidisciplinary approach.26 Rectovaginal fistulas (RVFs), a unique subset of fistulas in many respects, may be classified as “low,” with a tract between the distal anal canal (at or below the dentate line) and the inside of the posterior fourchette; “high,” with a tract connecting the upper vagina (at the level of the cervix) with the rectum; and “middle” with a tract that lies in between these levels.27–29 The terms “anovaginal fistula” and “low rectovaginal fistula” may be used interchangeably. RVFs may also be classified as “simple” or “complex.” Simple RVFs have a low, small-diameter (<2 cm) communication between the anal canal and vagina and typically result from obstetrical injury or infection.29 “Complex” RVFs involve a higher tract between the rectum and vagina, are of a larger diameter, or result from radiation, cancer, or complications of pelvic surgical procedures.30–33 RVFs most commonly occur as a result of obstetric injury29 but may also occur in the setting of Crohn’s disease,25 malignancy, or infection,32 or as a complication of a failed colorectal anastomosis,33 an anorectal operation,34 or radiation therapy.35 The surgical treatment of a particular fistula is influenced by the patient’s presenting symptoms, unique anatomy of the fistula tract, quality of the surrounding tissues, and previous attempts at fistula repair.36 This guideline addresses the management of cryptoglandular fistulas, RVFs, and anorectal fistulas in the setting of Crohn’s disease. MATERIALS AND METHODS These guidelines were built on the last clinical practice guidelines for the management of anorectal abscess and fistula-in-ano published in 2016.37 An organized search was performed of MEDLINE, PubMed, Embase, and the Cochrane Database of Systematic Reviews between December 1, 2015, and November 5, 2021. Key word combinations using MeSH terms included abscess, fistula, fistula-in-ano, anal, rectal, perianal, perineal, rectovaginal, anovaginal, seton, fistulotomy, stem cell, advancement flap, ligation of intersphincteric fistula tract (LIFT), fistula plug, fistula glue, video-assisted anal fistula treatment (VAAFT), fistula laser closure (FiLaC), over-the-scope clip (OTSC) device, and Crohn’s disease. The search was restricted to English-language articles and studies of adult patients. Directed searches using embedded references from primary articles were performed in selected circumstances, and other sources including practice guidelines and consensus statements from relevant societies were also reviewed. The 841 screened articles were evaluated for their level of evidence, favoring clinical trials, meta-analysis/systematic reviews, comparative studies, and large registry retrospective studies during single-institutional series, retrospective reviews, and peer-reviewed, observational studies. A final list of 269 sources was evaluated for methodologic quality, the evidence base was analyzed, and a treatment guideline was formulated by the subcommittee for this guideline (Fig. 1). The final grade of recommendation and level of evidence for each statement were determined using the Grades of Recommendation, Assessment, Development, and Evaluation system (Table 2). When the agreement was incomplete regarding the evidence base or treatment guideline, consensus from the committee chair, vice chair, and 2 assigned reviewers determined the outcome. Members of the ASCRS Clinical Practice Guidelines Committee worked in joint production of these guidelines from inception to final publication (Table 3). The entire Clinical Practice Guidelines Committee reviewed the recommendations formulated by the subcommittee. Final recommendations were approved by the ASCRS Executive Council. In general, each ASCRS Clinical Practice Guideline is updated every 5 years. No funding was received for preparing this guideline, and the authors have declared no competing interests related to this material. This guideline conforms to the Appraisal of Guidelines for Research and Evaluation checklist. TABLE 2. - The GRADE system: grading recommendations Description Benefit versus risk and burdens Methodologic quality of supporting evidence Implications 1A Strong recommendation, high-quality evidence Benefits clearly outweigh risks and burdens or vice versa RCTs without important limitations or overwhelming evidence from observational studies Strong recommendation, can apply to most patients in most circumstances without reservation 1B Strong recommendation, moderate-quality evidence Benefits clearly outweigh risks and burdens or vice versa RCTs with important limitations (inconsistent results, methodologic flaws, indirect or imprecise) or exceptionally strong evidence from observational studies Strong recommendation, can apply to most patients in most circumstances without reservation 1C Strong recommendation, low- or very-low quality evidence Benefits clearly outweigh risks and burdens or vice versa Observational studies or case series Strong recommendation but may change when higher-quality evidence becomes available 2A Weak recommendation, high-quality evidence Benefits closely balanced with risks and burdens RCTs without important limitations or overwhelming evidence from observational studies Weak recommendation, best action may differ depending on circumstances or patients’ values or societal values 2B Weak recommendation, moderate-quality evidence Benefits closely balanced with risks and burdens RCTs with important limitations (inconsistent results, methodologic flaws, indirect or imprecise) or exceptionally strong evidence from observational studies Weak recommendation, best action may differ depending on circumstances or patients’ values or societal values 2C Weak recommendation, low- or very-low quality evidence Uncertainty in the estimates of benefits, risks, and burdens; benefits, risks, and burdens may be closely balanced Observational studies or case series Very weak recommendations; other alternatives may be equally reasonable GRADE = Grades of Recommendation, Assessment, Development, and Evaluation; RCT = randomized controlled trial.Adapted from Guyatt et al.38 Used with permission. TABLE 3. - What is new in the 2022 ASCRS Clinical Practice Guidelines for the management of anorectal abscess, fistula-in-ano, and rectovaginal fistula? 2022 New recommendations 11. Minimally invasive approaches to treat fistula-in-ano that use endoscopic or laser closure techniques have reasonable short-term healing rates but unknown long-term fistula healing and recurrence rates. Grade of recommendation: weak recommendation based on low-quality evidence, 2C. 19. Anorectal fistula associated with Crohn’s disease is typically managed with a combination of surgical and medical approaches. Grade of recommendation: strong recommendation based on moderate-quality evidence, 1B. 25. Local administration of mesenchymal stem cells is a safe and effective treatment for selected patients with refractory anorectal fistulas in the setting of Crohn’s disease. Grade of recommendation: weak recommendation based on moderate-quality evidence, 2B. 2022 Updated recommendations 5. Antibiotics should typically be reserved for patients with an anorectal abscess complicated by cellulitis, systemic signs of infection, or underlying immunosuppression. Grade of recommendation: weak recommendation based on moderate-quality evidence, 2C→2B. 9. A cutting seton may be used selectively in the management of complex cryptoglandular anal fistulas. Grade of recommendation: weak recommendations based on low-quality evidence, 2B→2C. 10. The anal fistula plug and fibrin glue are relatively ineffective treatments for fistula-in-ano. Grade of recommendation: strong recommendation based on moderate-quality evidence, 2B→1B. 21. Draining setons are typically useful in the multimodality therapy of fistulizing anorectal Crohn’s disease and may be used for long-term disease control. Grade of recommendation: strong recommendation based upon moderate-quality evidence, 1C→1B. 22. Symptomatic, simple, low anal fistulas in carefully selected patients with Crohn’s disease may be treated by lay-open fistulotomy. Grade of recommendation: weak recommendation based on low-quality evidence, 1C→ 2C. 23. Endorectal advancement flaps and the LIFT procedure may be used to treat fistula-in-ano associated with Crohn’s disease. Grade of recommendation: strong recommendation based on moderate-quality evidence, 2B→1B. ASCRS = American Society of Colon and Rectal Surgeons; LIFT = ligation of intersphincteric fistula tract. FIGURE 1.: PRISMA literature search flow sheet. PRISMA = Preferred Reporting Items for Systematic Reviews and Meta-Analyses.Initial Evaluation of Anorectal Abscess and Fistula 1. A disease-specific history and physical examination should be performed evaluating symptoms, relevant history, abscess and fistula location, and presence of secondary cellulitis. Grade of recommendation: strong recommendation based on low-quality evidence, 1C. Anorectal abscess is usually diagnosed on the basis of a patient’s history and physical examination. Anorectal pain and swelling are common with superficial abscesses, whereas spontaneous drainage and fever occur less often.8–10,38 Deeper abscesses, including those in the supralevator or high ischiorectal spaces, may present with pain referred to the perineum, lower back, or buttocks.6,39,40 Evaluation of the anus and perineum may reveal erythema, calor, fluctuance, cellulitis, or tenderness on palpation or may be relatively unrevealing, particularly in patients with intersphincteric or deeper abscesses,6,10,40,41 and digital rectal examination and anoscopy/proctoscopy are occasionally needed to clarify the diagnosis. The differential diagnosis of anorectal abscess may include fissure, hemorrhoid thrombosis, pilonidal disease, hidradenitis, anorectal neoplasia, Crohn’s disease, and sexually transmitted infections.6,42,43 Patients who present with anal fistula typically report intermittent anorectal swelling and drainage. Relevant information about baseline anal sphincter function, history of anorectal operations, family history of IBD, obstetric history, and associated GI, genitourinary, or gynecologic pathology should typically be included in the patient’s history. Inspection of the perineum should involve noting the specific findings of an abscess, surgical scars, anorectal deformities, signs of possible anorectal Crohn’s disease, and the presence of an external fistula opening. Gentle probing of an external opening, when tolerated, may help confirm the presence of a fistula tract but should be done with care to avoid creating false tracts.43 Goodsall’s rule, that an anterior fistula-in-ano has a radial tract and a posterior fistula has a curvilinear tract to the anus, has generally proven to be accurate for anterior fistulas but is less accurate in cases with a posterior fistula.44–47 2. Routine use of diagnostic imaging is not typically necessary for patients with anorectal abscess or fistula. However, imaging may be considered in selected patients with an occult anorectal abscess, recurrent or complex anal fistula, immunosuppression, or anorectal Crohn’s disease. Grade of recommendation: strong recommendation based on moderate-quality evidence, 1B. In a retrospective study of 113 patients with anorectal abscess, the overall sensitivity of CT for detecting an abscess was 77% and the sensitivity of CT in immunosuppressed patients was 70%.48 An advantage of MRI over CT is its ability to identify anorectal abscesses and associated fistula tracts. In a study of 54 patients with anorectal Crohn’s disease, in which MRI and operative/clinical findings were compared, all the abscesses and 82% of the fistulas were correctly identified by MRI.49 In a 2014 prospective study of 50 patients with suspected anorectal fistula, MRI had a 95% sensitivity, 80% specificity, and 97% positive predictive value in detecting and grading the primary fistula tract.50 In a retrospective study of 136 patients specifically looking at the role of MRI in the preoperative assessment of fistula patients, Konan et al51 found that MRI identified “significant” findings defined as secondary (blind) tracts, horseshoe abscesses, or abscesses undiagnosed by physical examination or examination under anesthesia in 34% of patients. In this study, MRI provided significant findings more frequently for complex fistulas than for simple fistulas (54% vs 5%; p < 0.001). Additionally, the proportion of patients who had significant MRI contributions increased with increasing Parks grade (5% for grade 1; 48% for grade 2; 86% for grade 3; 87.5% for grade 4). A prospective trial published in 2019, including 126 patients, assessed the utility of 3-dimensional endoanal ultrasound (EAUS) and MRI in both simple (n = 68) and complex (n = 58) anal fistulas and reported comparable accuracy for the 2 modalities in cases of a simple fistula; however, MRI had significantly higher sensitivity evaluating secondary extensions in complex fistulas (97% vs 74%; p = 0.04).52 Endoanal ultrasound, in 2 or 3 dimensions and with or without peroxide enhancement, may be useful in the management of patients with abscess or fistula, and studies demonstrate concordance between EAUS and operative findings in 73% to 100% of cases.53–55 Tantiphlachiva et al56 found that preoperative EAUS may help preserve anorectal function in patients undergoing anal fistula surgery. This study retrospectively evaluated pre- and postoperative Fecal Incontinence Severity Scores in 109 patients who underwent preoperative EAUS and in 230 patients without preoperative imaging and found significantly worse Fecal Incontinence Severity Scores in the group that did not undergo preoperative EAUS at a mean follow-up of 34 weeks. The potential added value of combining diagnostic modalities to enhance the accuracy of anal fistula assessment was exemplified in a 2001 blinded study of 34 patients with anorectal Crohn’s disease in which EAUS was accurate in 91% of patients, MRI was accurate in 87% of patients, and examination under anesthesia was accurate in 91% of patients, whereas 100% accuracy was achieved when any 2 techniques were combined.57 The sensitivity, accuracy, and utility of transperineal ultrasound (TPUS), a noninvasive alternative to EAUS, have also been studied in patients with anorectal abscess, anoperineal fistulas, and RVFs.58–61 A prospective study of 23 patients with Crohn’s disease comparing the diagnostic accuracies of EAUS, TPUS, and MRI with operative findings found that the diagnostic accuracy of all 3 modalities was nearly identical.62 The authors concluded that TPUS might be considered first-line imaging because of its availability, low cost, and noninvasive nature, yet because of its operator dependency and lack of high-quality supporting data, this imaging technique has not gained widespread popularity. Anorectal Abscess 3. Patients with acute anorectal abscess should be treated promptly with incision and drainage. Grade of recommendation: strong recommendation based on low-quality evidence, 1C. The primary treatment of anorectal abscess remains surgical drainage. In general, the incision should be made large enough to provide adequate drainage while taking care not to injure the anal sphincter complex. The perianal incision should be kept as close as possible to the anal verge to minimize the length of a subsequent fistula tract should one develop. Alternatively, a surgical drain (eg, Pezzer, Malecot) can be placed into the abscess cavity63,64 if this provides adequate drainage, although this technique typically does not address loculations within an abscess cavity and generally omits primary fistulotomy. Small comparative analyses have shown comparable efficacy and higher patient satisfaction with drain placement compared to incision and drainage.65–67 Once an abscess has been drained, randomized trials report equivalent or superior abscess resolution rates with less pain and faster healing in patients whose wounds were left unpacked.68,69 After drainage, abscesses may recur in up to 44% of patients, most often within 1 year of initial treatment.2,10,70 Inadequate drainage, the presence of loculations or a horseshoe-type abscess, and not performing a primary fistulotomy are risk for recurrent abscess fistulotomy is addressed in recommendation Abscess generally a patient should have internal versus external drainage. Intersphincteric abscesses should typically be through the intersphincteric or into the anal canal via an internal it is usually to drain supralevator abscesses from the complicated of an intersphincteric abscess by the rectal to fistula supralevator abscesses because of of an ischiorectal abscess should typically be through the perianal These approaches to abscess drainage may help complex fistula that the can be to These abscesses most often involve the space and into the ischiorectal these circumstances, primary lay-open fistulotomy should typically be because these fistulas to be The a technique that the space and to address the ischiorectal spaces, is effective in the setting of a horseshoe although it may anal sphincter A technique using a posterior to the space seton placement has a high rate of abscess resolution and has been reported to preserve anorectal function compared to other operative Abscess drainage with concomitant fistulotomy may be performed in selected patients with simple anal fistulas. Grade of recommendation: weak recommendation based on moderate-quality evidence, 2B. Although 30% to 70% of patients with anorectal abscesses present with a concomitant the role of primary fistulotomy at the of abscess drainage remains Although a fistulotomy may address the and inflammation from the may the risk of a false tract when probing a fistula and can it to the the to the of sphincter randomized studies evaluating primary fistulotomy have reported results with to fistula recurrence and fecal and in a randomized controlled found that of patients treated with primary and internal had whereas reported postoperative sphincter at a follow-up of meanwhile, of 34 patients treated with incision and drainage had recurrence and reported postoperative and in a retrospective of patients treated with fistulotomy or sphincter found that after was significantly more common in patients who had a complex fistula compared to those who had a simple fistula A Cochrane that included patients from randomized controlled trials demonstrated that sphincter fistulotomy or at the of incision and drainage was associated with a significantly of abscess of fistula or abscess, or for subsequent 95% but an not incidence of at the randomized trials included in this patients with complex fistulas, recurrent abscesses, IBD, preexisting incontinence, or history of anorectal and included patients with low fistulas. Given the potential of a fistulotomy, have performing a fistulotomy with placement of a seton through the tract. A retrospective evaluated the of patients with low transsphincteric fistulas who underwent fistulotomy and then seton placement patients were patients who had anal sphincter function underwent a fistulotomy. This study reported that at 1 all patients who underwent fistulotomy reported no fistula or abscess recurrence or incontinence, supporting the of seton placement followed by fistulotomy in selected patients with a low transsphincteric When a simple fistula is encountered during incision and drainage of an anorectal abscess, fistulotomy may be performed in selected patients provided that the of healing the potential risk of fecal However, a seton to treat a fistula at the of incision and drainage patients to with a procedure to address their 5. Antibiotics should typically be reserved for patients with an anorectal abscess complicated by cellulitis, systemic signs of infection, or underlying immunosuppression. Grade of recommendation: weak recommendation based on moderate-quality evidence, 2B. In general, after performing an incision and drainage of a anorectal abscess in a patient does not healing or the recurrence rate and is typically not However, may be used selectively in patients with an anorectal abscess complicated by cellulitis, systemic or underlying Given the available evidence, the grade of this clinical practice guideline recommendation was from a 2C grade in to a 2B A retrospective study of patients with anorectal abscess who underwent incision and drainage with (n = or without (n = subsequent therapy for 5 to reported that of all patients related to anorectal infection, but was no significant between the in this Patients with surrounding cellulitis, or signs of systemic who did not had a in the rate of recurrent abscess compared with patients who received although this did not The authors also concluded that abscesses does not management or A study evaluated the of postoperative on fistula after incision and drainage of an anorectal In this randomized trial by and patients were treated with incision and drainage with or without a postoperative of and of patients in the treatment group an anal fistula versus 30% in the group < 0.001). to this study, et studied patients in a trial who no of with to anal fistula Although anorectal abscesses is not considered has been reported in up to of When is from an anorectal abscess, a combination of abscess drainage and directed the is typically for patients with systemic signs of or should also be considered in cases of recurrent infection or that an important role in treatment for or immunosuppressed patients with an anorectal Although patients with a higher and on examination typically have high resolution

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The American Society of Colon and Rectal Surgeons (ASCRS) is dedicated to ensuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Clinical Practice Guidelines Committee is composed of society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus and to develop clinical practice guidelines based on the best available evidence. Although they are not proscriptive, these guidelines provide information on which decisions can be made and do not dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. These guidelines should not be deemed inclusive of all proper methods of care nor exclusive of methods of care reasonably directed toward obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient. STATEMENT OF THE PROBLEM Colorectal cancer remains the third most common cancer for both men and women, and the second leading cause of cancer-related deaths in the United States annually. It is projected that 145,600 new colorectal cancer cases will have been diagnosed and an estimated 51,020 deaths from colorectal cancer will have occurred in 2019.1 It is difficult to estimate statistics attributable specifically to rectal cancer because, historically, much of the reporting for rectal cancer has been combined with colon cancer as the single disease entity of "colorectal cancer."1 Overall, the incidence of colorectal cancer has declined over the past decades, largely because of risk factor modification and screening.2 However, the 18- to 50-year age group represents a unique cohort of patients in whom the incidence of rectal cancer has been increasing. In contrast to overall trends, rectal cancer incidence increased by 1.8% annually in younger adults between 1990 and 2013.1 In an effort to ensure that patients with rectal cancer receive appropriate care using a multidisciplinary approach, the ASCRS collaborated with a multispecialty effort to develop the National Accreditation Program in Rectal Cancer to create educational modules and a set of clinical standards focusing on program management, clinical services, and quality improvement regarding rectal cancer.3,4 Because rectal cancer management involves multiple disciplines working in conjunction with one another, the surgical guidelines presented here must be viewed within that context and represent only a portion of the treatment necessary for the optimal care of patients with rectal cancer. Colorectal cancer screening, bowel preparation, enhanced recovery pathways, surveillance after curative treatment, and prevention of thromboembolic disease, while relevant to the management of patients with rectal cancer, are beyond of the scope of these guidelines and are addressed in other guidelines.5–9 A guideline focusing on colorectal surgery and frailty is forthcoming. METHODOLOGY These guidelines are based on the last set of ASCRS Practice Parameters for the Management of Rectal Cancer published in 2013.10 A systematic search of MEDLINE, PubMed, Embase, and the Cochrane Database of Collected Reviews was performed from January 1, 2013 through January 15, 2020. Individual literature searches were conducted for each of the different sections of the guideline (Fig. 1). An additional limitation to core clinical journals was applied if the initial word combination search returned more than 500 articles. Directed searches using embedded references from primary articles were performed in selected circumstances. The 1812 screened articles were evaluated for their level of evidence, favoring clinical trials, meta-analysis/systematic reviews, comparative studies, and large registry retrospective studies over single institutional series, retrospective reviews, and peer-reviewed, observational studies. Additional references identified through embedded references and other sources as well as practice guidelines or consensus statements from relevant societies were also reviewed. A final list of 361 sources was evaluated for methodologic quality, the evidence base was examined, and a treatment guideline was formulated by the subcommittee for this guideline. The final grade of recommendation and level of evidence for each statement were determined using the Grades of Recommendation, Assessment, Development, and Evaluation system (Table 1). When agreement was incomplete regarding the evidence base or treatment guideline, consensus from the committee chair, vice chair, and 2 assigned reviewers determined the outcome. Members of the ASCRS Clinical Practice Guidelines Committee worked in joint production of these guidelines from inception to final publication. Recommendations formulated by the subcommittee were reviewed by the entire Clinical Practice Guidelines Committee. Final recommendations were approved by the ASCRS Executive Council. In general, each ASCRS Clinical Practice Guideline is updated every 5 years. No funding was received for preparing this guideline, and the authors have declared no competing interests related this material. This guideline conforms to the Appraisal of Guidelines for Research and Evaluation (AGREE) checklist.TABLE 1.: The GRADE system: grading recommendationsFIGURE 1.: PRISMA literature search flow sheet. CPG = Clinical Practice Guideline.Defining the Rectum The lower limit of the rectum is usually defined by the anorectal ring, an anatomic landmark palpable on physical examination or visible radiographically as the upper border of the anal sphincter and puborectalis muscles.11 The upper limit of the rectum has been variably defined by the splaying of the teniae coli, the sacral promontory, the proximal valve of Houston, or the level of the peritoneal reflection. A recent consensus conference defined the point of the sigmoid take-off (ie, the junction of the sigmoid mesocolon and mesorectum) as seen on cross-sectional imaging as the upper limit of the rectum.12 Given that the correlation among these landmarks is imperfect and the presence of all 3 valves of Houston is inconsistent, the upper limit of the rectum, from a clinical perspective, can be somewhat elusive. In practice, the location of a rectal cancer is most commonly assessed by the distance from its distal margin to the anal verge, defined as the beginning of the hair-bearing skin. Tumors within 15 cm of the anal verge are typically classified as rectal cancers, although the total length of the rectum can vary by body habitus and sex.11 PREOPERATIVE ASSESSMENT Evaluation 1. A cancer-specific history should be obtained eliciting disease-specific symptoms, associated symptoms, family history, and perioperative medical risk. Routine laboratory values, including CEA level, should also be evaluated, as indicated. Grade of recommendation: Strong recommendation based on moderate-quality evidence, 1B. A cancer-specific history remains a cornerstone of the preoperative evaluation. Bleeding, pain, or symptoms related to obstruction should be assessed to help determine the urgency and sequence of evaluation and intervention; this consideration is particularly relevant when neoadjuvant therapy is being considered. Urinary, sexual, and bowel function should be reviewed and symptoms indicative of malignant fistulas or severe radiating pain may alert the surgeon to locally advanced disease involving adjacent pelvic organs. The patient's medical fitness to undergo multimodality treatment should be assessed to guide treatment planning and perioperative management. A thorough discussion of perioperative risk stratification is beyond the scope of this guideline.13–15 A family history should typically document relevant premalignant lesions and cancers including details like the age at diagnosis and the lineage of affected first- and second-degree relatives. Patients should be asked about known predisposing hereditary cancer syndromes, prior genetic testing, and family ancestry or ethnicity that may be relevant.16 Patients with findings suggestive of an inherited susceptibility to colorectal cancer should typically be referred for genetic counseling. Guidelines on the management of patients with inherited colorectal cancer have been previously published.17,18 Routine laboratory bloodwork and a CEA level are part of the preoperative evaluation. The baseline CEA level before initiating elective treatment is prognostic of long-term survival and is used as a reference during posttherapy surveillance.19 Although CEA levels assessed at different time points during multimodality treatment can correlate with treatment response, CEA does not reliably predict pathologic response to neoadjuvant therapy.20–23 There is insufficient evidence to support the routine use of other tumor markers such as CA19-9 in the evaluation of patients with rectal cancer.24 2. As a part of a complete physical examination, the distance of the distal extent of the cancer from the anal verge and the cancer's relation to the sphincter complex should typically be assessed. Grade of recommendation: Strong recommendation based on low-quality evidence, 1C. Assessment of the relationship between the distal extent of the lesion to both the anorectal ring (ie, top of the sphincter complex) as well as the anal verge is essential for treatment planning and for evaluating the patient's candidacy for sphincter preservation and should ideally be performed before initiating neoadjuvant therapy, which may cause regression of the lesion. The distance should be assessed by digital examination and endoscopically (rigid proctoscopy may provide a more accurate measurement than flexible sigmoidoscopy). Endoscopic tattooing for purposes of anticipated intraoperative localization or to facilitate mucosal surveillance in the event of a clinical complete response may be helpful.25–29 3. Before elective treatment, the histological diagnosis of invasive adenocarcinoma should be confirmed, and patients should typically undergo a full colonic evaluation so the treatment plan can address synchronous pathology, as needed. Grade of recommendation: Strong recommendation based on moderate-quality evidence, 1B. It is important to confirm the histological diagnosis of invasive adenocarcinoma before initiating therapy in the elective setting, because rectal neoplasms of other histologies may be amenable to nonresectional or different multimodality treatment options.30 Because endoscopic biopsy may be nondiagnostic or incongruent with the clinical impression of invasive adenocarcinoma because of a sampling error, repeat endoscopic or operative biopsies may be required to establish the histological diagnosis for purposes of treatment planning. Operative excisional biopsy is typically not performed unless it is done as a curative-intent transanal full-thickness excision with adequate radial margins as discussed in detail later. Patients newly diagnosed with rectal cancer should typically undergo a full colon evaluation. Although the incidence of synchronous colorectal cancer is low, in the range of 1% to 3%, the incidence of synchronous adenomas or other polyps can be as high as 30%.31–34 Colonoscopy is a preferred evaluation method because it offers a therapeutic platform to treat synchronous polyps.35,36 In cases where a colonoscopy is not completed, for instance, due to an obstructing cancer, CT colonography may be used.37–40 Computed tomography colonography has been shown to be a superior diagnostic study compared with double-contrast barium enema among patients with symptoms suggestive of colorectal cancer and can detect synchronous lesions.41 In patients receiving neoadjuvant therapy, colonoscopy may be reattempted if there is sufficient tumor regression to permit passage of a colonoscope. If a preoperative colon evaluation is not performed, typically in cases where urgent intervention is needed for obstructing lesions, a complete colonoscopy should be planned postoperatively. Staging 1. Rectal cancer should typically be staged according to the American Joint Committee on Cancer TNM system before initiating treatment. Grade of recommendation: Strong recommendation based on moderate-quality evidence, 1B. Rectal cancer should be staged according to the TNM system before treatment, except when emergent surgery is required. The TNM system, as defined by the American Joint Committee on Cancer, describes the depth of local tumor invasion (T stage), the extent of regional lymph node involvement (N stage), and the presence of distant metastasis (M stage).42,43 Updated 8th edition staging definitions categorize lymph nodes harboring micrometastasis (clusters of 20 or more cancer cells or metastases measuring >0.2 mm and <2 mm in diameter) as N1 disease, the presence of tumor deposits (N1c disease) as stage III regardless of the status of the lymph nodes, and peritoneal metastases as M1c disease.42,43 Rectal cancer should be described by both its initial clinical stage (cTNM), which guides treatment decisions, as well as the final pathologic stage (pTNM), which can provide prognostic information.42 Clinical stage can be further prefixed to designate the staging modality used, including u for ultrasound, mr for MRI, and ct for CT scan. For patients treated with preoperative therapy, pathologic tumor response is reported as ypTNM.44,45 2. Rectal cancer protocol pelvic MRI is the preferred modality for locoregional clinical staging. Endorectal ultrasound (EUS) may be considered when differentiating between early T stages (ie, T1 versus T2 tumors) or when MRI is contraindicated. Grade of recommendation: Strong recommendation based on moderate-quality evidence, 1B. Magnetic resonance imaging staging of rectal cancer, using standardized technical protocols and reporting templates, assesses the depth of tumor penetration, presence of locoregional nodal metastases, and the relationship between lesions (tumor and/or nodes) within the mesorectum and the mesorectal fascia.46,47 Thus, MRI can help predict surgical clearance of the circumferential resection margin (CRM), the shortest distance between disease (tumor and/or malignant nodes) and the mesorectal fascia.47–49 A positive CRM has been variably defined as cancer within 1 mm or within 2 mm50,51 of the mesorectal fascia or levator ani muscle; the National Comprehensive Cancer Network currently defines it as within 1 mm.52 A positive CRM is associated with increased risk for local recurrence and decreased survival (5-year local recurrence: HR = 3.50; 95% CI, 1.53–8.00; p < 0.05; 5-year overall survival: HR = 1.97; 95% CI, 1.27–3.04; p < 0.01).53–55 Primary tumor features including T4 status, extramural vascular invasion, CRM within 1 mm, or extramural tumor depth of at least 5 mm are considered high-risk features.56,57 These factors should be considered as a critical part of clinical staging and are vital for planning preoperative therapy as discussed in Multidisciplinary Treatment Planning. Endorectal ultrasound should typically be considered complementary to MRI for purposes of clinical staging and is most useful in differentiating between early T stages (ie, T1 versus T2 tumors).57 Magnetic resonance imaging may also be contraindicated when certain implantable medical devices are present (ie, metallic implants, MR incompatible pacemakers).58,59 Disadvantages of EUS include operator dependency, limited accuracy in assessing bulky or locally advanced lesions, patient discomfort, and inability to evaluate stenotic lesions that preclude passage of the transducer.58,59 Accurately staging potentially involved pelvic lymph nodes (including mesorectal, lateral pelvic, and inguinal compartments) remains a diagnostic challenge for all imaging modalities.60 Sensitivity and specificity for clinical nodal staging have been reported as 55% and 74% for CT, 67% and 78% for EUS, and 66% and 76% for MRI.48,61 Nodal staging accuracy may be improved by incorporating criteria such as a spiculated border and mixed signal intensity as seen on MRI.57,62,63 3. Clinical staging for metastatic disease should typically be conducted in patients with rectal cancer. Grade of recommendation: Strong recommendation based on moderate-quality evidence, 1B. Clinical staging of distant metastatic disease should typically be completed before initiating treatment, because the presence of metastatic disease influences the treatment plan. In patients with metastatic rectal cancer from the Swedish Cancer Registry, the most common sites of metastasis were liver (70%), lung (47%), bone (12%), and nervous system (8%).64 Clinical staging should typically include contrast-enhanced CT scan of the chest, abdomen, and pelvis. Pulmonary CT, with its increased sensitivity and better ability to arbitrate otherwise indeterminate lesions over time, is recommended rather than chest x-ray.65,66 Computed tomography without intravenous contrast followed by triphasic (arterial, venous, and portal) contrast is generally the modality of choice for detecting and characterizing hepatic lesions.67–69 For smaller lesions, and to evaluate a liver with background fatty liver changes, MRI may be superior to multidetector CT and positron emission tomography (PET). There is insufficient evidence to support the routine use of PET/CT alone in the clinical staging of primary rectal cancer.60 Although PET/CT has been used for staging patients with suspected disease recurrence or for excluding other sites of distant disease in patients with stage IV rectal cancer being considered for curative-intent surgery, the evidence supporting added clinical value is limited.70,71 Positron emission tomography /CT may have a role in evaluating equivocal findings on contrast-enhanced CT.72,73 4. Restaging evaluation should be considered after neoadjuvant therapy in patients with locally advanced rectal cancer. Grade of recommendation: Strong recommendation based on low-quality evidence, 1C. Restaging evaluation consisting of clinical and endoscopic assessment and cross-sectional imaging should typically be considered after neoadjuvant therapy, in particular, if the assessment of local tumor response would influence the need for additional therapy and/or alter the surgical approach, or if there is a unique concern for interval development of metastatic disease. Importantly, restaging evaluates patients for a possible clinical complete response (cCR) and can adjust patient expectations. Some studies have demonstrated a change in treatment strategy after restaging in 11% to 15% of patients, typically due to identification of metastatic disease, but others have shown limited or no benefit to restaging.74,75 Although restaging is typically performed by repeating the same imaging studies that were done initially, the assessment of tumor response to neoadjuvant therapy has been challenging because of limited T and N staging accuracy for MRI, CT, or EUS in this setting.76–79 Advanced functional MRI (ie, diffusion-weighted MRI) and/or PET/CT scan may potentially improve the accuracy of assessing treatment response.70,80 Multidisciplinary Treatment Planning 1. The treatment of patients with rectal cancer should typically incorporate a multidisciplinary team tumor board discussion. Grade of recommendation: Strong recommendation based on low-quality evidence, 1C. Optimal management of patients with rectal cancer requires input and coordination among a team of clinicians including expertise from surgery, pathology, radiology, radiation, and medical oncology, and other ancillary team members. Although discussion of rectal cancer management by an multidisciplinary team can improve preoperative clinical staging, modify and multimodality treatment, plan technical of surgery, and pathologic staging, more studies are needed to a on and overall survival 2. If a or is being preoperative and should typically be Grade of recommendation: Strong recommendation based on moderate-quality evidence, 1B. with an is typically recommended for patients rectal cancer treatment may and patient can improve time to and Guidelines on and surgery have been previously and Operative 1. excision is an appropriate treatment modality for selected patients with rectal cancer without high-risk Grade of recommendation: Strong recommendation based on moderate-quality evidence, 1B. excision is an curative-intent treatment in selected patients with rectal cancer with clinical and histological excision may also be appropriate for patients with more advanced disease but who are considered for cancer surgery. local excision offers of operative risk and functional it does not or stage the mesorectal lymph The risk of nodal metastasis from T1 lesions from to 11% with risk associated with pathologic features such as invasion, tumor and or preoperative staging and patient are essential when local early depth of invasion (ie, may be difficult with MRI, and EUS may be as a complementary staging in certain Clinical criteria for local excision typically include limited to of the rectal that are well or without invasion, invasion, tumor on and no clinical nodal and that are for full-thickness Given of the of local the grade of this statement has been from a in the 2013 guidelines to a local excision involves full-thickness ideally with a mm circumferential margin with a depth to a of a The surgeon should typically the to facilitate pathologic and or excision should be if The procedure can be performed as a transanal excision or by using a transanal endoscopic platform like transanal endoscopic or transanal invasive surgery there is a of trials, studies that offers better and to more proximal lesions than transanal and and to be Endoscopic an advanced can potentially treat lesions with invasion, but the optimal patient criteria for this The of local recurrence local excision from to for T1 lesions and is than that after Patients should that if pathologic examination risk factors like T invasion, tumor or or invasion, resection will typically be In general, local excision is considered an treatment for lesions because the local recurrence from to and these have an risk for harboring nodal resection should typically be recommended these circumstances. When patients with high-risk T1 and T2 lesions resection or sphincter in combination with local excision has been considered. In a systematic of patients with rectal lesions by local who on to receive = were compared to who resection = the limited retrospective and the local recurrence for and resection were CI, versus CI, for lesions and 15% CI, versus CI, for Thus, in high-risk patients who or are for should typically be recommended after local excision and should be followed by surveillance for a potentially excision has also been performed after neoadjuvant for This has been in clinical assigned and patients with rectal cancer to neoadjuvant and local excision versus reported no in local recurrence or However, a demonstrated high of in particular, pain and for These patients regarding possible long-term and the and of this in routine clinical 1. A thorough surgical should typically be performed at the time of Grade of recommendation: Strong recommendation based on low-quality evidence, 1C. should typically include a thorough assessment of the peritoneal and the to detect or metastatic disease radiographically more advanced local disease to adjacent synchronous lesions, or findings that the operative plan and the to with the be before the vascular and to a 2. For curative resection of of the upper third of the rectum, a mesorectal excision should typically be performed as part of a resection with the mesorectum at least 5 cm the distal margin of the For of the and lower of the rectum, total mesorectal excision should typically be performed as a part of an resection or resection A distal margin is usually adequate for distal rectal cancers when combined with A distal margin is generally for cancers at or the mesorectal Grade of recommendation: Strong recommendation based on the high-quality evidence, surgical is to and and should the and anatomic of a between the and of the fascia of the rectal cancer and associated and tumor excision can the and intraoperative and the of local patients in Research and the local recurrence was for the group with a (ie, of compared with for the group with a (ie, of = Importantly, distal mesorectal of rectal cancer further than distal Although distal is beyond 1 cm from the distal of the cancer in only to of rectal deposits of distal mesorectal nodal can to 3 to cm distal to the primary address the for both and mesorectal for of the upper rectum, the mesorectal excision should typically 5 cm the distal of the for of the and lower rectum, a (ie, excision of all mesorectum to its most distal is required with a distal rectal resection margin at least 2 For of the distal rectum at or the mesorectal a margin of 1 cm in conjunction with a in selected distal margins may be in selected patients who are for sphincter preservation and who have demonstrated tumor regression after neoadjuvant In cases where preoperative anal function and distal pathologic clearance are may be followed by of an colorectal or In cases where the tumor involves the anal sphincter or the levator where

The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Colonic Volvulus and Acute Colonic Pseudo-Obstruction.

The Level of Evidence Pyramid: Indicating Levels of Evidence in Plastic and Reconstructive Surgery Articles

Rapid eye movement sleep behavior disorder (RBD) is a parasomnia characterized by dream enactment behaviors and rapid eye movement sleep without atonia (RWA). It is associated with a significantly increased risk of conversion to neurodegenerative diseases. Currently, the clinical diagnosis and management of RBD remain insufficiently standardized, while early identification and intervention are crucial for improving disease outcomes. To raise awareness and attention among clinicians towards RBD and provide guidance for its standardized management, experts in the fields of neurology and sleep medicine in China formulated the guideline for diagnosis and treatment of RBD. This guideline was established in accordance with the current evidence-based medicine to standardize the diagnosis and treatment of RBD in China. Based on systematic literature reviews and international grading systems for recommendations and evidence levels, the guideline systematically summarized the epidemiology, etiology, classification, pathogenesis, clinical manifestations, auxiliary examinations, diagnosis, differential diagnosis, treatment, as well as prognosis and outcomes of RBD. A total of five recommendations were formulated in the field of treatment. The guideline aimed to provide scientific and standardized guidance for the clinical management of RBD.

Objectives This 2023 update of the WFSBP guidelines for the pharmacological treatment of eating disorders (EDs) reflects the latest diagnostic and psychopharmacological progress and the improved WFSBP recommendations for the assessment of the level of evidence (LoE) and the grade of recommendation (GoR). Methods The WFSBP Task Force EDs reviewed the relevant literature and provided a timely grading of the LoE and the GoR. Results In anorexia nervosa (AN), only a limited recommendation (LoE: A; GoR: 2) for olanzapine can be given, because the available evidence is restricted to weight gain, and its effect on psychopathology is less clear. In bulimia nervosa (BN), the current literature prompts a recommendation for fluoxetine (LoE: A; GoR: 1) or topiramate (LoE: A; GoR: 1). In binge-eating disorder (BED), lisdexamfetamine (LDX; LoE: A; GoR: 1) or topiramate (LoE: A; GoR: 1) can be recommended. There is only sparse evidence for the drug treatment of avoidant restrictive food intake disorder (ARFID), pica, and rumination disorder (RD). Conclusion In BN, fluoxetine, and topiramate, and in BED, LDX and topiramate can be recommended. Despite the published evidence, olanzapine and topiramate have not received marketing authorisation for use in EDs from any medicine regulatory agency.

Diffuse large B-cell lymphoma (DLBCL): ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

Urinary tract infection (UTI) is a source of morbidity and healthcare costs in adults with spina bifida (ASB). UTI prevention strategies are often recommended, but the evidence of various approaches remains unclear. We performed a systematic review to inform a best practice policy statement for UTI prevention in ASB. On behalf of the Neurogenic Bladder Research Group (NBRG.org), we developed an a priori protocol and searched the published English literature for 30 outcomes questions addressing UTI prevention in ASB. The questions spanned the categories of antibiotics, oral supplements, bladder management factors and social support. Where there was little literature in ASB, we included literature from similar populations with neurogenic bladder (NB). Data was abstracted and then reviewed with recommendations made by consensus of all authors. Level of Evidence (LoE) and Grade of Recommendation (GoR) were according to the Oxford grading system. Of 6,433 articles identified by our search, we included 99 publications. There was sufficient evidence to support use of the following: saline bladder irrigation (LoE 1, GoR B), gentamicin bladder instillation (LoE 3, GoR C), single-use intermittent catheterization (IC) (LoE 2, GoR B), hydrophilic catheters for IC (LoE 2, GoR C), intradetrusor onabotulinumtoxinA injection (LoE 3, GoR C), hyaluronic acid (HA) instillation (LoE 1, GoR B), and care coordination (LoE 3, GoR C). There was sufficient evidence to recommend against use of the following: sterile IC (LoE 1, GoR B), oral antibiotic prophylaxis (LoE 2, GoR B), treatment of asymptomatic bacteriuria (LoE 2, GoR B), cranberry (LoE 2, GoR B), methenamine salts (LoE 1, GoR B), and ascorbic acid (LoE1, GoR B). There was insufficient evidence to make a recommendation for other outcomes. Overall, there are few studies in UTI prevention in the specific population of ASB. Research in populations similar to ASB helps to guide recommendations for UTI prevention in the challenging patient group of ASB. Future studies in UTI prevention specific to ASB are needed and should focus on areas shown to be of benefit in similar populations.

Management of Premenstrual Syndrome: Green-top Guideline No. 48.