Intersphincteric Resection Research Articles

Intersphincteric resection and coloanal anastomosis in the treatment of distal rectal cancers

ObjectiveIn the evolving era of minimal access surgery, low rectal cancers still pose a challenge to laparoscopic or robotic surgeons. Hence, at our institute we intended to demonstrate the oncological efficacy of intersphincteric resection and coloanal anastomosis in the treatment of distal rectal cancers, performing the abdominal part of the procedure which includes rectal mobilization, laparoscopically. MethodsFrom February 2017 to March 2021, 125 patients who had undergone intersphincteric resection and coloanal anastomosis via the perineal approach at Galaxy Care Laparoscopic Institute, Pune, were included in this study. Transabdominal mobilization of the rectum was performed laparoscopically. All patients had a diversion ileostomy and a pelvic drain. Patients were followed-up for a period of 18 months post-surgery. Data on clinical and oncological outcomes were collected and analysed. The pre-operative and post-operative Wexner incontinence scores were compared. ResultsThe mean time taken for surgery was 181.57 ± 30.00 min. The mean blood loss was 119.76 ± 42.53 mL. Most patients (103, 82.4%) had their tumour at a distance of 1–2 cm from the anal verge. A loco-regional recurrence rate of 12.8% (16/125) was noted in our study. For the post-surgery Wexner score, 74.4% of patients (93/125) had a score of 5 or less, depicting that three-quarters of the study population had satisfactory continence. Overall, 81.6% of patients were satisfied with the functional results of surgery. ConclusionIntersphincteric resection and coloanal anastomosis, with a 12.8% recurrence rate, can now be considered an oncological and technically feasible procedure with sphincter salvage and good continence.

Single-center comparative study of short-term outcomes of transanal and laparoscopic total mesorectal excisions for low and middle rectal cancers.

Transanal total mesorectal excision is a promising surgical treatment for rectal cancer. However, evidence regarding the differences in outcomes between the transanal and laparoscopic total mesorectal excisions is scarce. We compared the short-term outcomes of transanal and laparoscopic total mesorectal excisions for low and middle rectal cancers. This retrospective study included patients who underwent low anterior or intersphincteric resection for middle (5-10cm) or low (< 5cm) rectal cancer at the National Cancer Center Hospital East, Japan, from May 2013 to March 2020. Primary rectal adenocarcinoma was confirmed histologically. Circumferential resection margins (CRMs) of resected specimens were measured; margins ≤ 1mm were considered positive. The operative time, blood loss, hospitalization length, postoperative readmission rate, and short-term treatment results were compared. Four hundred twenty-nine patients were divided into two mesorectal excision groups: transanal (n = 295) and laparoscopic (n = 134). Operative times were significantly shorter in the transanal group than in the laparoscopic group (p < 0.001). The pathological T stage and N status were not significantly different. The transanal group had significantly lower positive CRM rates (p = 0.04), and significantly lower incidence of the Clavien-Dindo grade III (p = 0.02) and IV (p = 0.03) complications. Both groups had distal margin positivity rates of 0%. Compared to laparoscopic, transanal total mesorectal excision for low and middle rectal cancers has lower incident postoperative complication and CRM-positivity rates, demonstrating the safety and usefulness of local curability for middle and low rectal cancers.

Morbidity and oncological outcomes after intersphincteric resection of the rectum for low-lying rectal cancer: experience of a single center in a lower-middle-income country

BackgroundIntersphincteric resection (ISR) of the rectum for low-lying rectal cancer with colo-anal anastomosis was introduced years ago, allowing for bowel continuity, and avoiding permanent stomas. The colorectal unit of Korle Bu Teaching Hospital adopted this procedure in 2014 when indicated, for the management of rectal cancers, where hitherto, abdominoperineal resection of the rectum with a permanent stoma was indicated. This study aimed to assess morbidity, mortality, and oncological outcomes associated with ISR of the rectum and determine the factors contributing to these.MethodsThis was an observational study from prospectively stored data. All patients who underwent intersphincteric resection of the rectum due to low-lying rectal cancer from July 2014 to June 2021 were included in the study, and their records were assessed for intra-operative and 30-day postoperative complications, as well as mortality and their related risk factors and their oncological outcomes in terms of local recurrence at one year.Results102 patients were included in this analysis. Six percent (6/102) of patients had intra-operative complications, including bleeding, and 41% (42/102) had 30-day postoperative complications, which were associated with pelvic side wall attachment of tumor and intra-op complications. Mortality risk was 12.7% (13/102) in the early postoperative period, and nine patients had a local recurrence within the first year of surgery.ConclusionThere is a high risk of early postoperative morbidity and mortality after intersphincteric resection of the rectum in our setting. The oncological outcomes are favorable in a population that abhors a permanent colostomy.

Single-stapling technique versus hand-sewn anastomosis in inter-sphincteric resection with transanal total mesorectal excision (Super SST): protocol for a multicentre randomized clinical trial

Currently, hand-sewn anastomosis is the standard procedure for inter-sphincteric resection (ISR); however, distal purse-string suturing during transanal total mesorectal excision (TaTME) has allowed a single-stapling technique (SST). Although it was originally intended for cases requiring anastomosis of 2 cm or more above the anorectal junction (ARJ), SST could be safely performed in ISR. The aim of this trial is to determine the superiority of SST over hand-sewn anastomosis in ISR with TaTME. The Super SST trial is a multicentre randomized clinical trial comparing stapled and hand-sewn anastomoses in ISR with TaTME. The trial will recruit patients scheduled for TaTME with anastomosis below the ARJ, who will be allocated 1:1 to receive either hand-sewn or stapled anastomosis. The primary endpoint is anastomosis-related complications within 30 postoperative days. Secondary endpoints include all early and late complications, operating time, reoperation, mortality rate, length of postoperative hospital stay, readmission, incidence of anal pain and rectal mucosal prolapse, length of temporary stoma retention, the proportion of patients with a temporary stoma at 1 year after surgery, and anorectal function at 1 year after surgery. This trial will provide important clinical insights for new and promising anastomotic options for patients with very low rectal cancer. Registration number: UMIN000047818 (https://www.umin.ac.jp/ctr/index-j.htme).

Comparison of postoperative anorectal function between hand-sewn and stapled anastomoses in intersphincteric resection with transanal total mesorectal excision.

Comparison of postoperative anorectal function between hand-sewn and stapled anastomoses in intersphincteric resection with transanal total mesorectal excision.

Functional outcomes after robotic or laparoscopic intersphincteric resection - An inverse probability weighting analysis.

Functional outcomes after robotic and laparoscopic Intersphincteric resections (ISR) have not been studied adequately. We aimed to compare the bowel functions after robotic or laparoscopic ISR. Single-center, cross-sectional study of minimally invasive ISR. Functional outcomes were assessed on the low anterior resection syndrome (LARS), Wexner incontinence scale, and the Kirwan grading. Baseline characteristics (age, sex, body mass index, T stage, tumour height, preoperative radiation, and anastomotic configuration) in the groups were balanced using inverse probability of treatment weighting (IPTW). Functional outcomes were assessed for 132 patients, 85 laparoscopic and 47 robotic ISR were performed. After IPTW, baseline characteristics were well balanced (mean deviation <0.1). In the weighted cohorts of laparoscopic and robotic ISR, major LARS was observed in 18.1% and 18.5% (p - 0.182) and major incontinence on the Wexner scale in 18.4% and 22.8% (p - 0.443), respectively. The Kirwan grades of incontinence were also similar between the groups (p - 0.794). No differences in bowel functions on the LARS and incontinence scales between laparoscopic and robotic ISR were found in the present study.

Surgical treatment of rectal cancer: prospective cohort study about good oncologic results and low rates of abdominoperineal excision.

the purpose of this study was to evaluate the outcome of rectal cancer surgery, in a unit adopting the principles of total mesorectal excision (TME) with a high restorative procedure rate and with a low rate of abdominoperineal excision (APE). we enrolles patients with extraperitoneal rectal cancer undergoing TME or TME+APE. Patients with mid rectal tumors underwent TME, and patients with tumors of the lower rectum and no criteria for APE underwent TME and intersphincteric resection. Those in which the intersphincteric space was invaded and in those with a free distal margin less than 1cm or a tumor free radial margin were unattainable underwent APE or extralevator abdominoperineal excision (ELAPE). We assessed local recurrence rates, overall survival and involvement of the radial margin. sixty (89.6%) patients underwent TME and seven (10.4%) TME + APE, of which five underwent ELAPE. The local recurrence, in pacientes undergoing TME+LAR, was 3.3% and in patients undergoing APE, 14.3%. The local recurrence rate (p=0.286) or the distant recurrence rate (p=1.000) was similar between groups. There was no involvement of radial margins. Survival after 120 months was similar (p=0.239). rectal malignancies, including those located in the low rectum, may be surgically treated with a low rate of APE without compromising oncological principles and with a low local recurrence rates.

Surgical Treatment for Mucosal Prolapse after Intersphincteric Resection

はじめに：括約筋間直腸切除術後（Intersphincteric resection：ISR）後の粘膜脱は，治療法として確立されたものはないが，当科ではDelorme手術を施行しており，その臨床経験を報告する．結果：2010年6月から2020年12月の間に直腸癌に対し36例にISRを施行した．ISR術後粘膜脱を4例（11.1％）に認め，うち3例にDelorme手術を施行した．周術期の合併症は認めなかった．粘膜脱の再発を1例に認め永久人工肛門造設となったが，他の2例は再発なく経過している．結語：ISR術後の粘膜脱に対してDelorme手術は安全に施行でき，治療の選択肢の1つとなり得る術式であった．しかし粘膜脱を再発する症例も認めており，粘膜脱の機序や術式の検討を継続すべきであると考えられた．

Technical, functional, and oncological validity of robot-assisted total-intersphincteric resection (T-ISR) for lower rectal cancer.

Few studies fairly compared anorectal function and prognostic outcomes between patients undergoing abdominoperineal resection (APR) and anorectal-function-saving operations (ASO) under the equivalent conditions. By contrast, surgeons used to be somewhat hesitant to conduct total intersphincteric resection (T-ISR) as maximal ASO, due to its technical complexity and potential anorectal dysfunction. Propensity-score matched cohorts undergoing robot-assisted R0 surgery [T-ISR vs APR vs partial-subtotal ISR (PS-ISR)/lower anterior resection (LAR)] for rectal cancer (n=1361) were included. Operative outcomes, recurrence, and disease-free/overall survival (DFS/OS) were analyzed. Anorectal function was evaluated based on fecal incontinence score and high-resolution manometry between the T-ISR and other ASO groups. Few differences were detected between the T-ISR and APR groups. More patients undergoing APR had T4 stage disease, while the lowest tumor margin was the same in both groups (mean, 1.5cm from anal verge). Prognostic outcomes did not differ between the T-ISR and APR groups, including local (5.1% vs 7.7%, p=1) or systemic (15.4% vs 25.6%, p=0.401) recurrence, and 5-year DFS (78.7% vs 61.5%, p=0.1) and OS (89% vs 82.1%, p=0.434) rates, nor were there differences between the T-ISR and PS-ISR/LAR groups. The PS-ISR group generally showed less anorectal dysfunction than the T-ISR group, but maximal tolerance volume did not differ between these two groups and was within the range for the healthy population. T-ISR can replace most traditional APR, except for advanced T4 disease with aggressive infiltration into the levator-sphincters, and can provide tolerable anorectal dysfunction.

New indication area in intersphincteric resection: transanal total mesorectal excision combined with intersphincteric resection.

New indication area in intersphincteric resection: transanal total mesorectal excision combined with intersphincteric resection.

Indocyanine green fluorescence imaging during laparoscopic rectal cancer surgery could reduce the incidence of anastomotic leakage: a single institutional retrospective cohort study

BackgroundThere is insufficient evidence on whether indocyanine green (ICG) fluorescence angiography can reduce the incidence of anastomotic leakage (AL). This retrospective cohort study aimed to evaluate the effect of ICG fluorescence angiography on AL rates in laparoscopic rectal cancer surgery at a single institution.MethodsPatients who underwent laparoscopic low anterior resection or intersphincteric resection with ICG fluorescence angiography (ICG group; n = 73) and patients who underwent a similar surgical procedure for rectal cancer without ICG fluorescence (non-ICG group; n = 114) were enrolled consecutively in this study. ICG fluorescence angiography was performed prior to transection of the proximal colon, and anastomosis was performed with sufficient perfusion using ICG fluorescence imaging. AL incidence was compared between both groups, and the risk factors for AL were analyzed.ResultsAL occurred in 3 (4.1%) and 14 (12.3%) patients in the ICG and non-ICG groups, respectively. In the ICG group, the median perfusion time from ICG injection was 34 s, and 5 patients (6.8%) required revision of the proximal transection line. None of the patients requiring revision of the proximal transection line developed AL. In univariate analysis, longer operating time (odds ratio: 2.758; 95% confidence interval: 1.023–7.624) and no implementation of ICG fluorescence angiography (odds ratio: 3.266; 95% confidence interval: 1.038–11.793) were significant factors associated with AL incidence, although the creation of a diverting stoma or insertion of a transanal tube was insignificant.ConclusionICG fluorescence angiography was associated with a significant reduction in AL during laparoscopic rectal cancer surgery. Changes in the surgical plan due to ICG fluorescence visibility may help improve the short-term outcomes of patients with rectal cancer.

Trends of sphincter-preserving surgeries for low lying rectal cancer: A 20-year experience in China.

Over the last 2 decades, patients with low rectal cancer have had better outcomes from improvements in surgical techniques in sphincter preservation. We aimed to quantify the trends in sphincter-preserving surgeries for low rectal cancer over 20 years in a top tertiary hospital in China. Between 1999 and 2021, a cohort of patients with primary malignant rectal tumor ≤5cm from the anal verge and who received elective surgeries at Changhai Hospital, Shanghai, China, was identified. Data were extracted from electronic medical records. A Joinpoint Regression Model was used to analyze trends in surgical procedures by average annual percentage change (AAPC). Adjusted Cox proportional hazards regression model was used to assess overall survival. Among a total of 4,172 patients during the study period, 3,111 (74.6%) underwent a sphincter-preserving surgery and 1,061 (25.4%) received APR. Sphincter-preserving surgery increased 3.6% per year (95%CI, 2.3-4.9). Low anterior resection was the most performed procedure (86.3%) and maintained a steady trend, while intersphincteric resection increased 49.4% annually (95%CI, 19.5-86.7) after initiation. Laparoscopic techniques increased 15.1% per year (95%CI, 8.4-43.4) after initiation. Sphincter-preserving surgery increased annually for tumors ≤2cm, 2-≤3cm and 3-≤4cm from the anal verge (AAPC 7.1, 4.5-9.8; 4.7, 3.1-6.3; 2.7, 1.7-3.6, respectively). Furthermore, patients with sphincter-preserving surgery had a better overall survival than abdominoperineal resection (APR) patients (adjusted HR 0.78, 95% CI, 0.65-0.93, p=.01). Utilization of sphincter-preserving surgeries increased significantly over the last 20 years. Patients with low rectal cancer who underwent sphincter preservation had better survival than similar patients who underwent APR.

Risk factor and nomogram for predicting the probability of a permanent stoma after laparoscopic intersphincteric resection for ultralow rectal cancer

Objective: A permanent stoma can seriously affect patients' quality of life. Clinicians need to consider the risk of a permanent stoma when making clinical decisions. This study analyzed preoperative predictors of a permanent stoma after laparoscopic intersphincteric resection for low rectal cancer (LISR), and a prediction model was constructed validated. Methods: This was a retrospective study that analyzed clinical data of 331 ultralow rectal cancer patients who were diagnosed with primary rectal adenocarcinoma by endoscopy and pathology, including 218 males and 113 female, (58.8±11.2) years and (23.7±3.1) kg/m2. The patients underwent LISR with a preventive stoma from January 2012 to December 2020. Patients with multiple primary colorectal cancers, who underwent emergency surgery for intestinal obstruction or bleeding or perforation, and did not complete 18 months follow up were exclucled. R software was used to randomly select 234 patients as the modeling group with a ratio of approximately 7:3, and the remaining 97 patients comprised the validation group. The stoma site was determined by the surgeon before the operation, and the ileum 30 cm from the ileocecal valve was selected. The rates of a permanent stoma for the entire group and the preoperative clinical factors that may affect the permanency of a stoma in the modeling group were determined. A permanent stoma was defined as failure to close the stoma at 18 months after surgery. Multivariate logistic regression analysis was used to analyze the preoperative independent risk factors for a permanent stoma after LISR. R software was used to create the nomogram model, and the predictive ability of the nomogram model was evaluated by receiver operating characteristic (ROC) curve analysis. Results: Among the 331 patients who underwent LISR, 37 (26 cases in the modeling group and 11 cases in the validation group, 11.2%) developed a permanent stoma for the following reasons: anastomotic stenosis due to leakage (16 cases, 43.2%), distant metastasis (16 cases, 43.2%), intolerant to stoma closure surgery (3 cases, 8.1%), stenosis due to postoperative radiation (1 case, 2.7%), and poor recovery of anorectal function (1 case, 2.7%). Univariate analysis showed that preoperative neoadjuvant chemoradiotherapy, poorly differentiated tumor, cT3 stage, and distant metastasis were associated with a permanent stoma. Multivariate logistic regression analysis showed that neoadjuvant chemoradiotherapy [OR=3.078, 95% confidence interval (CI): 1.326-7.147; P=0.009], cT3 stage (OR=2.257, 95%CI: 1.001-5.091; P=0.049), and stage IV cancer (OR=16.180, 95%CI: 2.753-95.102; P=0.002) were independent risk factors for permanent stoma after LISR. Based on the selected risk factors, a nomogram model for predicting permanent stoma was constructed. The area under the ROC curve of the modeling group was 0.793, the optimal cut-off value was 0.890, the sensitivity was 0.577, and the specificity was 0.885. The area under the ROC curve of the validation group was 0.953. The corrected curves of the modeling group and the validation group showed a good degree of fit. Conclusion: Neoadjuvant chemoradiotherapy, cT3 stage, and distant metastasis are independent predictors of a permanent stoma after LISR, and the nomogram model is helpful to predict the probability of a permanent stoma. Patients with high-risk factors should be adequately informed of the risk of a permanent stoma before colorectal surgery.

Transanal down-to-up dissection of the distal rectum as a viable approach to achieve total mesorectal excision in laparoscopic sphincter-preserving surgery for rectal cancer near the anus: a study of short- and long-term outcomes of 123 consecutive patients from a single Japanese institution

BackgroundIn rectal cancer (RC) surgery, the complexity of total mesorectal excision (TME) in laparoscopic sphincter-preserving surgery (lap-SPS) for RC near the anus has been a critical issue. Recently, technical assistance via the anus for complete TME has been receiving attention. This study aimed at clarifying the transanal down-to-up dissection viability for achieving TME in lap-SPS for RC near the anus.MethodsWe evaluated surgical and oncological outcomes of a total of 123 consecutive patients undergoing either a transanal rectal dissection (TARD) under direct vision mobilizing the most difficult portion of TME via the anus or the transanal TME by using an endoscopic system (TaTME) for achieving TME in lap-SPS for RC near the anus between January 2006 and February 2021.ResultsA total of 123 consecutive patients (83 men) with a median age of 66 years (range 33–86 years) were included. TARD and TaTME were performed for 50 (40.7%) and for 73 (59.3%) patients, respectively. Preoperative treatment was performed for 40 (32.5%) patients, resulting in a complete pathological response in 5 (12.5%) patients. Intersphincteric resection was performed significantly more in the TARD group (p<0.001). Although the TaTME group needed a longer operative time at the transanal portion (p<0.001), the median blood loss was lower (p<0.001). Postoperative complications with the Clavien–Dindo classification grade ≧2 developed in 52 (42.3%) patients. Urinary dysfunction and stoma-related complications were found most frequently. More patients needing medication for urinary dysfunction were found in the TARD group, but a significant difference was not observed (10.0% vs. 6.8%, p=0.526). The quality of TME was good for almost all patients. Recurrence developed in 18 (14.6%) patients. The 5-year overall survival (OS) and relapse-free survival (RFS) rates in 123 patients were 95.8% and 88.8%, respectively. The 5-year OS and RFS between the two groups were comparable.ConclusionsOur data suggested that a transanal down-to-up dissection of the distal rectum might be a viable approach in lap-SPS for RC near the anus. Further studies are needed to examine the differences between TARD and TaTME.

Laparoscopic intersphincteric resection vs. transanal total mesorectal excision in overweight patients with low rectal cancer.

ObjectiveAnus-preserving surgery in overweight patients with low rectal cancer has been a challenge due to the narrow operating space. Intersphincteric resection (ISR) was once a standard therapeutic option for low rectal cancer. The effectiveness of transanal total mesorectal excision (taTME) in treating this group of patients remains uncertain as a new surgical strategy. The aim of this study was to evaluate the short-term effects of taTME with ISR in overweight patients with low rectal cancer.MethodsA total of 53 patients with low rectal cancer were treated with taTME in 31 cases and ISR in 22 cases. The surgery-related data, pathological manifestations of surgical specimens, postoperative recovery, and postoperative complications were compared.ResultsPatients in both groups completed the surgery successfully. There were no significant differences in operative time, blood loss, anastomotic distance from the anal verge and ileostomy between the two groups (P > 0.05). TaTME group performed or virtually finished resection of the rectal mesentery, and no positive cases of Circumferential Resection Margin (CRM) or Distal Resection Margin (DRM) were detected in either group. The number of lymph nodes found in surgical specimens did not change significantly between the two groups (P = 0.391). In the subgroup analysis, however, more lymph nodes were detected in female patients undergoing taTME than in male patients (P = 0.028). The ISR group took less time to remove the drainage tubes (P = 0.013) and the same results were obtained in both groups of male patients in the subgroup analysis (P = 0.011). There were no statistically significant differences in time to start liquid diet, time to remove catheters, time to start flatus, time to begin ambulation, postoperative hospital stay, and readmission within 30 days after surgery between the two groups (P > 0.05). However, female patients in the taTME group were initiated ambulation earlier than males in the subgroup analysis (P = 0.034). The difference was insignificant in the occurrence of postoperative complications between the two groups (P > 0.05).ConclusiontaTME is safe and feasible for the treatment of overweight patients with low rectal cancer.

Robotic vs. laparoscopic intersphincteric resection for low rectal cancer: a case matched study reporting a median of 7-year long-term oncological and functional outcomes.

Aim of this study was to compare operative, long-term oncological and functional outcomes of laparoscopic (LISR) and robotic (RISR) intersphincteric resection in low-lying rectal cancer. Retrospective analysis of prospectively maintained database was performed. 115 cases (LISR, n = 55; RISR, n = 60) were performed by a single surgeon (January 2011-January 2020). Clinical characteristics did not differ between the groups. Operating time was longer in RISR (160.0 ± 45.7 vs. 205.0 ± 36.5min, p = 0.035). There was no conversion in RISR, whereas in LISR, two patients (3.6%) converted to open surgery. Complete mesorectum was 61.8% and 83.3% for LISR and RISR (p = 0.046), respectively. Circumferential radial margin involvement was 10.9% and 8.3% in LISR and RISR (p = 0.365), respectively. Median follow-up was 82.8 (30-138) months for LISR and 83.6 (30-138) months for RISR. Three-, five-, and seven-year overall survival rates (OS) for LISR and RISR were: 88.6%, 80.4%, 73.4% and 90.4%, 86.3%, 76.9%, respectively. Three-, five-, and seven-year disease-free survival (DFS) rates for LISR and RISR were 80.5%, 75.2%, 70.4% and 84.4%, 81.4%, 79.8% (p = 0.328), respectively. Three-, five-, and seven-year local recurrence-free survival rates in LISR and RISR were: 96.1%, 92.6%, 88.4% and 96.7%, 94.2%, 90.4% (p = 0.573), respectively. Mean Wexner score for LISR (n = 32) and RISR (n = 40) was: 10.5 ± 4.7 and 9.8 ± 4.2 (p = 0.782), respectively. Colostomy-free survival in LISR and RISR was: 3 years 94.5%/95.2%, 5 years 89.1%/91.7%, and 7 years 83.6%/85.0%. RISR is associated with better mesorectal integrity, no conversion, and lower postoperative complication rate. RISR has longer operation time. Oncological and anorectal functional outcomes are similar in both groups.

Trans-Anastomotic Drainage Tube Placement After Hand-Sewn Anastomosis in Patients Undergoing Intersphincteric Resection for Low Rectal Cancer: An Alternative Drainage Method.

Anastomotic leakage (AL) is a common complication after intersphincteric resection (ISR). It significantly reduces quality of life and causes great distress to patients. Although traditional drainage (e.g., anal and pelvic catheters) may reduce the impact of AL to some extent, their role in reducing the incidence of AL remains controversial. In this study, we developed a novel drainage technique involving the placement of drainage tubes through the gap between sutures during handsewn anastomosis, to reduce the occurrence of anastomotic leakage. We retrospectively analyzed 34 consecutive patients who underwent intersphincteric resection requiring handsewn anastomosis between February 1, 2017, and January 1, 2021. Patients were classified into the trans-anastomotic drainage tube group (TADT, n = 14) and the non-TADT group (n = 20) based on whether trans-anastomotic tube placement was performed. The incidence of postoperative complications, such as AL, was compared between the two groups, and anal function of patients at 1-year post-ISR was evaluated. Six cases of AL occurred in the non-TADT group, while none occurred in the TADT group; this difference was statistically significant (p=0.031). The TADT group also had a shorter hospital stay (p=0.007). There were no other significant intergroup differences in operation time, blood loss, pain score, anastomotic stenosis, intestinal obstruction, or incidence of wound infection. In the 30 patients (88.2%) evaluated for anal function, there were no significant intergroup differences in stool frequency, urgency, daytime/nocturnal soiling, Wexner incontinence score, or Kirwan grading. Taken together, trans-anastomotic tube placement is a novel drainage method that may reduce AL after ISR requiring handsewn anastomosis and without adversely affecting anal function.

Influence of different sphincter-preserving surgeries on postoperative defecation function

Advances in surgical techniques and treatment concept have allowed more patients with low rectal cancer to preserve sphincter without sacrificing survival benefit. However, postoperative dysfunctions such as fecal incontinence, frequency, urgency, and clustering often occur in patients with low rectal cancer. The main surgical procedures for low rectal cancer include low anterior rectum resection (LAR), intersphincteric resection (ISR), coloanal anastomosis (Parks) and so on. The incidence of major LARS after LAR is up to 84.6%. The postoperative function of ISR is even worse than LAR. Moreover, the greater the extent of resection ISR surgery, the worse the postoperative function. There are few studies on the function of Parks procedure. Current evidence suggests that the short-term function of Parks procedure is inferior to LAR, but function can gradually recovered over time. Colorectal surgeons have attempted to improve postoperative defecation by modifying bowel reconstructions. Current evidence suggests that J pouch or end-to-side anastomosis during LAR does not reduce the incidence of defecation disorders. Pouch reconstruction during ISR cannot reduce the incidence of severe LARS either. In general, the protection of postoperative defecation function in patients with low rectal cancer still has a long way to go.

Reassessment of intersphincteric resection in the sphincter-preserving operation for ultra-low rectal cancer

Intersphincteric resection (ISR), as an ultra-low sphincter-preserving operation, is widely used in clinical practice at present. ISR can allow some patients with very low rectal cancer to avoid the pain of anal resection while ensuring oncological efficacy. However, the procedure of ISR requires wider intersphincteric dissection which may cause nerve damage, and the removal of partial or total internal anal sphincter as an "inherent defect" of ISR can result in poor anal function postoperatively. Based on the in-depth understanding of regional anatomy and physiological function, the author proposed a new functional sphincter preservation operation for very low rectal cancer-conformal sphincter preservation operation (CSPO) which has achieved good outcome in clinical practice. This article will revisit the brief history of rectal cancer surgery and discuss the main mechanisms underlining the poor anal function after ISR. Based on the anatomical study of the pelvic floor and anal canal, CSPO can improve the postoperative anal function of very low rectal cancer patients by reducing the damage of the autonomic nerves, receptor corpuscles and muscle fibers in the intersphincteric space, retaining more dentate line and internal sphincter with the design of resection line of tumor lower border under direct vision, and elevating the anastomosis height. At the same time, the future treatment prospect of low rectal cancer is envisioned.

Functional outcomes of intersphincteric resection in low rectal tumors.

Currently, sphincter-saving procedures are increasingly performed in the treatment of low rectal cancers. This study aimed to evaluate the outcomes of patients who underwent intersphincteric resection. This was a single-center, retrospective, cross-sectional study. We evaluated the electronic data files of 29 patients who had intersphincteric resections at our institute between 2008 and 2018. Bowel function outcomes were assessed prospectively using Wexner incontinence score. Histopathological, surgical and functional outcomes were analyzed. Mean age of nine female and 20 male patients included in the study was 55.8 ± 12.8 (30-76) years. A tumor-free surgical margin was achieved in all patients. Anastomotic leakage was detected in two patients. Mean Wexner incontinence score of 20 patients who still had functional anastomosis was 8.35, whereas 65% of the patients (n= 13) had a good continence status. There was no relationship between the continence status and sex, tumor distance from anal verge, T stage, distal surgical margin, and lymph node involvement. Twenty-one patients underwent primary coloanal anastomosis and eight patients underwent two-stage coloanal anastomosis. In the treatment of distal rectal cancer, adequate oncological surgery and relatively acceptable functional outcomes can be obtained with intersphincteric resection technique in suitable patients.