Maximum Tolerable Volume Research Articles

Anal sphincter dysfunction in patients treated with primary radiotherapy for anal cancer: a study with the functional lumen imaging probe

Background: Sphincter-sparing radiotherapy or chemoradiation are standard treatments for patients with anal cancer. The ultimate treatment goal is full recovery from anal cancer with preserved anorectal function. Unfortunately, long-term survivors often suffer from severe anorectal symptoms. The aim of the present study was to characterize changes in anorectal physiology after radiotherapy for anal cancer.Method: We included 13 patients (10 women, age 63.4 ± 1.9) treated with radiotherapy or chemoradiation for anal cancer and 14 healthy volunteers (9 women, age 61.4 ± 1.5). Symptoms were assessed with scores for fecal incontinence and low anterior resection syndrome. Anorectal physiology was examined with anorectal manometry and the Functional Lumen Imaging Probe.Results: Patients had a median Wexner fecal incontinence score of 5 (0–13) and a median LARS score of 29 (0–39). Compared to healthy volunteers, patients had lower mean (±SE) anal -resting (38 ± 5 vs. 71 ± 6, p < .001) and -squeeze pressures (76 ± 11 vs. 165 ± 15, p < .001). Patients also had lower anal yield pressure (15.5 ± 1.3 mmHg vs. 28.0 ± 2.0 mmHg, p < .001), higher distensibility, and lower resistance to flow (reduced resistance ratio of the anal canal during distension, q = 5.09, p < .001). No differences were found in median (range) rectal volumes at first sensation (70.5 (15–131) vs. 57 (18–132) ml, p > .4), urge (103 (54-176) vs. 90 (32-212), p > .6) or maximum tolerable volume (173 (86–413) vs. 119.5 (54–269) ml, p > .10).Conclusion: Patients treated with radiotherapy or chemoradiation for anal cancer have low anal resting and squeeze pressures as well as reduced resistance to distension and flow.

Study on anorectal dynamics of biofeedback therapy for fecal incontinence in patients with low rectal cancer after restorative resection

Objective This study intends to elaborate the effect of biofeedback therapy on postoperative defecation dysfunction in low rectal cancer by anorectal dynamics index, and to observe the effects and mechanism of biofeedback in the treatment of the process in detail. Methods 80 patients with low rectal cancer preparing for anterior resection were randomized for surgical treatment, treatment group 50 cases, and 30 cases in the control group. The treatment group received biofeedback therapy for 3 months, control group did not do special treatment, continuous observation patients Preoperative, before biofeedback treatment and at the end of 1, 3, 6, 9, 12 month about anorectal dynamics index and meaning, continence, feeling the change of function, defecation time and defecation time. Observed over the same period in control group during the experiment as the treatment group. Results After biofeedback training in the treatment group, the first 12 months of follow-up anal resting pressure (t=9.903, P=0.004), anal maximal systolic blood pressure (t=6.737, P=0.007)and rectal maximum tolerable volume were significantly (t=8.040, P=0.006) improved compared with before biofeedback treatment, that of (188.4±41.1) ml, (189.9±36.4) mmHg (1 mmHg=0.133 kPa) and (47.6±8.0) mmHg. But rectal sensory threshold capacity (t=2.362, P=0.823)and rectal defecation feeling capacity (t=3.507, P=0.583)were not significantly increased compared with before biofeedback therapy [(20.9±5.3) ml and (46.2±10.9) ml]. Postoperative patients in the treatment group before biological feedback therapy and biofeedback therapy for twelfth months later, anorectal defecation function was significantly improved (χ2=10.729, P=0.004), difference was statistically significant. The treatment group compared with the control group for twelfth months, the difference was statistically significant (χ2=37.777, P=0.002). Conclusion Biofeedback therapy can improve the anal function in patients with low or very low rectal cancer after restorative resection. Key words: Low rectal caicinoma; Restorative resection; Fecal incontinence; Biofeedback therapy

High-resolution anorectal manometry in children with functional constipation: a single-centre experience before and after treatment.

IntroductionConstipation is a common disorder among children, and most of the cases are functional in aetiology. Few studies have reported the manometric data of normal and constipated children.AimTo evaluate the manometric parameters in children with functional constipation and to assess any possible changes in these parameters after treatment.Material and methodsA prospective descriptive study was conducted at a single centre, enrolling 50 children diagnosed with functional constipation based on Rome IV criteria. Their age ranged from 6 to 14 years with a mean of 7.31 ±1.72 years. High-resolution manometry was performed on all children at the initial presentation and after six months of treatment.ResultsThe studied children showed markedly abnormal rectal sensation parameters (increased first sensation, first urge, intense urge, and maximum tolerable volume) during rectal balloon distension. These parameters were even higher in children with stool incontinence (p = 0.005). Manometric data after 6 months of treatment showed that the resting and squeeze pressures were increased when compared to pre-treatment recordings; however, both were statistically insignificant (p = 0.474 and p = 0.155, respectively). Abnormalities in rectal sensations and the manometric parameters reached near normal values following treatment.ConclusionsAnorectal manometry is sensitive in predicting improvement in patient condition even before complete clinical cure, and it has a prognostic role in the management of childhood constipation. More research is still needed before recommending anorectal manometry as a routine diagnostic or prognostic tool in paediatric constipation management.

Fecal incontinence in patients with spina bifida: The target is the rectum.

The prevalence rate of severe fecal incontinence (FI) in adults with spina bifida (SB) is high. The physiological basis of FI in SB has not been clearly established, which contributes to inadequate care. The aim was to better characterize a large cohort of adults with special consideration of anorectal physiology. A multidisciplinary team from a French referral centre for SB prospectively collected data on patients who had an anorectal manometry. Factors associated with severe FI (Cleveland clinical incontinence score ≥ 9) were assessed in a multivariate analysis model. A total of 132 adults with SB (sex ratio M/F: 55 [41.7%]/77 [58.3%]; mean age of 38.2 [11.6] years old) were assessed. Among these patients, 83/132 (62.9%) suffered from severe FI. Rectal perception was not evaluable among 17 patients who had a latex allergy. Overall, 29/115 (25.2%) had maximal tolerable volume (MTV) > 330 mL or no sensation. The absence of anal canal sensitivity, MVT > 330 mL and the amplitude of the recto-anal inhibitory reflex (RAIR) >75% after a rectal isovolumic inflation of 50 mL were significantly associated with severe FI in the multivariate analysis model. Neither neurological level nor other neurological features were associated with severe FI. This study showed that FI in patients with SB is mainly associated with rectal abnormalities. This should be taken into consideration to improve incontinence management of patients with SB.

The study on anorectal motility in elderly patients with chronic constipation

Objective To investigate the dynamic abnormality of anorectum in elderly patients with chronic constipation. Methods Anorectal perfusion manometry was performed to detect the change of anal canal pressure and the rectal sensation capacity in 58 elderly patients and 36 non-elderly adults with chronic constipation.The results were compared retrospectively. Results Anal resting pressure in a chronic constipation was significantly lower in elderly patients than in non-elderly adults, with statistically significant difference 〔(59.74±2.31)mmHg vs.(68.22±2.37)mmHg, t=2.430, P=0.017〕. The incidence of paradoxical motility of anal sphincter was significantly higher in elderly patients with three abnormalities(incomplete defecation, Bristol stool scale type 3-5 and straining at defecation)than in elderly patients without above three abnormalities(χ2=8.880、11.540、6.070, P=0.003、0.001、0.014). Maximal tolerable volume was significant lower in elderly patients with straining at defecation and abdominal pain than in control group(t=2.140, 2.260, both P<0.05). No correlation was observed between sex and anorectal motility in elderly patients with chronic constipation. Conclusions Anorectal motility in elderly patients with chronic constipation is different from that in non-elderly patients with chronic constipation.The dynamic abnormalities of anorectum in chronic constipation are different in elderly patients with different symptoms. Key words: Constipation; Anal canal; Manometry

Effects of NK1 receptors on gastric motor functions and satiation in healthy humans: results from a controlled trial with the NK1 antagonist aprepitant.

Aprepitant, an NK1 receptor antagonist, is approved for the treatment of chemotherapy-induced or postoperative emesis by blocking NK1 receptors in the brain stem vomiting center. The effects of NK1 receptors on gastric functions and postprandial symptoms in humans are unclear; a single, crossover study did not show a significant effect of aprepitant on gastrointestinal transit. Our aim was to compare, in a randomized, double-blind, placebo-controlled, parallel-group study (12 healthy volunteers per group), the effects of aprepitant vs. placebo on gastric emptying of solids (by scintigraphy) with a 320-kcal meal, gastric volumes (GVs; fasting and accommodation by single photon emission-computed tomography), satiation [maximum tolerated volume (MTV)], and symptoms after a dyspeptogenic meal of Ensure. Aprepitant (125 mg on day 1, followed by 80 mg on days 2-5) or placebo, one tablet daily, was administered for 5 consecutive days. Statistical analysis was by unpaired rank sum test, adjusted for sex difference and body mass index. To assess treatment effects on symptoms, we incorporated MTV in the model. Aprepitant increased fasting, postprandial, and accommodation GV and tended to increase volume to fullness and MTV by ~200 kcal. However, aprepitant increased aggregate symptoms, nausea, and pain scores after ingestion the MTV of Ensure. There was no significant effect of aprepitant on gastric half-emptying time of solids. We conclude that NK1 receptors are involved in the control of GV and in determining postprandial satiation and symptoms. Further studies of the pharmacodynamics and therapeutic role of NK1 receptor antagonists in patients with gastroparesis and dyspepsia are warranted.NEW & NOTEWORTHY Aprepitant increases fasting, postprandial, and accommodation gastric volumes. Aprepitant increases volume to fullness and maximum tolerated volume during a nutrient drink test. NK1 receptors are involved in the control of gastric volume and in determining postprandial satiation and symptoms.

Relationship of gastric emptying or accommodation with satiation, satiety, and postprandial symptoms in health.

The contributions of gastric emptying (GE) and gastric accommodation (GA) to satiation, satiety, and postprandial symptoms remain unclear. We aimed to evaluate the relationships between GA or GE with satiation, satiety, and postprandial symptoms in healthy overweight or obese volunteers (total n = 285, 73% women, mean BMI 33.5 kg/m2): 26 prospectively studied obese, otherwise healthy participants and 259 healthy subjects with previous similar GI testing. We assessed GE of solids, gastric volumes, calorie intake at buffet meal, and satiation by measuring volume to comfortable fullness (VTF) and maximum tolerated volume (MTV) by using Ensure nutrient drink test (30 ml/min) and symptoms 30 min after MTV. Relationships between GE or GA with satiety, satiation, and symptoms were analyzed using Spearman rank (rs ) and Pearson (R) linear correlation coefficients. We found a higher VTF during satiation test correlated with a higher calorie intake at ad libitum buffet meal (rs = 0.535, P < 0.001). There was a significant inverse correlation between gastric half-emptying time (GE T1/2) and VTF (rs = -0.317, P < 0.001) and the calorie intake at buffet meal (rs = -0.329, P < 0.001), and an inverse correlation between GE Tlag and GE25% emptied with VTF (rs = -0.273, P < 0.001 and rs = -0.248, P < 0.001, respectively). GE T1/2 was significantly associated with satiation (MTV, R = -0.234, P < 0.0001), nausea (R = 0.145, P = 0.023), pain (R = 0.149, P = 0.012), and higher aggregate symptom score (R = 0.132, P = 0.026). There was no significant correlation between GA and satiation, satiety, postprandial symptoms, or GE. We concluded that GE of solids, rather than GA, is associated with postprandial symptoms, satiation, and satiety in healthy participants.NEW & NOTEWORTHY A higher volume to comfortable fullness postprandially correlated with a higher calorie intake at ad libitum buffet meal. Gastric emptying of solids is correlated to satiation (volume to fullness and maximum tolerated volume) and satiety (the calorie intake at buffet meal) and symptoms of nausea, pain, and aggregate symptom score after a fully satiating meal. There was no significant correlation between gastric accommodation and either satiation or satiety indices, postprandial symptoms, or gastric emptying.

Influence of the patient-practitioner interaction context on acupuncture outcomes in functional dyspepsia: study protocol for a multicenter randomized controlled trial

BackgroundIn the treatment of functional dyspepsia, the placebo effect has been reported to be high, and the influence of the patient-practitioner relationship may be a major component of this effect. The specific and non-specific effects of acupuncture cannot be easily distinguished, and the patient-practitioner relationship may influence the total therapeutic effect in clinical practice. There have been no studies that investigate the influence of patient-practitioner relationship on acupuncture treatment for patients with functional dyspepsia.MethodsPatients with postprandial distress syndrome, a functional dyspepsia subtype, will be recruited at three hospitals (two in Korea and one in USA) for an international, multi-center, randomized, patient/assessor-blinded, clinical trial. The total anticipated sample size is 88. The participants will be randomly allocated into two groups: an augmented interaction group and a limited interaction group. Acupuncture, with total 12 acupoints, will be performed twice weekly for 4 weeks in both groups. Trained practitioners will provide an “augmented” or “limited” interaction context, as determined by random allocation. The primary outcome measure is the proportion of responders, the proportion of participants who answer “yes” to more than half of the adequate relief questions during the study. Secondary outcome measures include questionnaires for quality of life and symptoms of dyspepsia, and maximum tolerable volume of nutrient drink test. Data will be collected at baseline and following 4 weeks of acupuncture.DiscussionThis study will evaluate the influence of the patient-practitioner interaction on clinical effects of acupuncture in patients with functional dyspepsia.Trial registrationCRIS Identifier: (KCT0002229).

Role of recto-anal biofeedback in management of fecal incontinence: early experience for prospective non-surgical management

Background: Fecal incontinence is a difficult and debilitating problem with various nonsurgical and surgical modes of treatment. Biofeedback is among the most considerable nonoperative strategies. This study is to review of the short-term effectiveness of the use of biofeedback therapy in management of fecal incontinence.Methods: A retrospective review of 14 patients with fecal incontinence were included and completed the planned biofeedback sessions regarding clinical response and change in anorectal manometric parameters.Results: 14 incontinent patients (9 males and 5 females), mean age 38.0 ± 21.4 years, 6 patients (42.8%) showed excellent response (cured), 5 patients (35.7%) showed good response (improved) and 3 patients (21.5%) showed poor response. There were a highly significant decrease in the grade with mean 3.8±1.4 to 2.4±1.7 (P value =0.003) and a score mean 11.8±5.9 to 6.1±7.1 (P value = 0.002). increase in anal resting pressure by mean 33.6±18.1 mmHg (P value = 0.004) and anal squeeze pressure by mean 75.4±35.2 mmHg (P value = 0.002). Also increase in anal resting pressure from 36.2±13.4 mmHg to 46.0±19.7 mmHg (P value = 0.046) and the anal squeeze pressure 89.3±21.8 mmHg to 106.7±21.0 mmHg (P value = 0.026). the volume required for 1st sensation mean 34.6±10.8 cc. decreased to 29.3±9.4 cc. (P value = 0.048) and the maximum tolerable volume increases from 221.4±55.9 cc to 235.7±54.9 cc (P-value = 0.022).Conclusions: Biofeedback therapy has an effective role in short term efficacy in management of fecal incontinence.

Bilateral Posterior Tibial Nerve Stimulation in the Treatment of Rectal Evacuation Disorder: A Preliminary Report.

Posterior tibial nerve stimulation influences both motor and sensory pathways, as well as the central nervous system. Stimulation of posterior tibial nerve roots (L4 to S3) could improve stool evacuation through S3 and/or S2 stimulation. This study aimed to assess the efficiency of bilateral posterior tibial nerve stimulation in the treatment of rectal evacuation disorder without anatomic obstruction. This was a prospective case series studying the treatment of patients with obstructed defecation by posterior tibial nerve stimulation. The study was conducted at a tertiary referral academic medical center. Patients with rectal evacuation disorder without anatomic obstruction who were failing maximal conservative treatments were included. Thirty minutes of bilateral transcutaneous posterior tibial nerve stimulation was applied 3 times weekly for each patient for 6 consecutive weeks. The primary end point was the change in the modified obstructed defecation score. Secondary end points were changes in rectal sensitivity volumes (urge to defecate volume and maximal tolerable volume) and quality of life using the Patient Assessment of Constipation-Quality of Life questionnaire. Thirty-six patients (25 women) completed the trial. The mean age of patients was 57.2 years (SD = 14.4 y). No adverse events were reported. Symptomatic successful outcome was reported in 17 patients (47%) and modified obstructed defecation score decreased over 6 weeks (mean decrease = 10 points (95% CI, 8.7-11.3 points); p < 0.0001). Patients with successful outcome (responders) had relatively lower preoperative modified obstructed defecation score compared with patients with unsuccessful outcome (nonresponders). In the successful group, there were significant improvement after 6 weeks in both Patient Assessment of Constipation-Quality of Life score (mean improvement = 43.0 points (95% CI, 35.2-50.7 points); p < 0.0001) and rectal sensitivity (significant reductions in urge to defecate volume (from 258.1 ± 21.2 to 239.6 ± 15.3; p < 0.0001) and maximal tolerable volume (from 304.5 ± 24.8 to 286.8 ± 19.7; p < 0.0001)). No significant change in Patient Assessment of Constipation-Quality of Life or rectal sensitivity was observed in the nonresponders. The study was designed just to proof the concept, but small sample size is a limitation. Another limitation is the short duration of study of only 6 weeks. Current data showed that bilateral transcutaneous posterior tibial nerve stimulation can improve symptoms in a considerable percentage of patients with obstructed defecation without anatomic obstruction. The procedure is more effective in patients with a less-modified obstructed defecation score. Additional studies are needed to discover the predictive factors for success.

Pathophysiology of fecal incontinence in obese patients: A prospective case-matched study of 201 patients.

Obesity is an emerging risk factor for fecal incontinence (FI). The aim of this study was to characterize pathophysiologic mechanisms of FI in obese patients compared with non-obese patients in a prospective case-matched study. The general characteristics and data of the anorectal manometry and endosonography of patients who were evaluated for FI at a single institution from 2005 to 2015 were prospectively assessed. Fecal incontinence was defined by a Cleveland Clinic Incontinence Score (CCIS) >4. Obesity was defined by a body mass index ≥30kg/m2 . Obese patients were case-matched with two age- and sex-matched non-obese patients. A total of 201 patients were included (67 obese matched with 134 non-obese). The CCIS, Knowles-Eccersley-Scott Symptom Constipation Score and quality of life score were comparable between obese and non-obese patients with FI. Factors significantly associated with obesity in FI patients were cholecystectomy (odds ratio [OR]=3.45 [1.19-10.32], P=.0230), irritable bowel syndrome - diarrhea (OR=2.94 [1.22-7.19], P=.0158), upper part of the anal canal resting pressure ≥22mmHg (OR=3.45 [1.45-8.76], P=.0045), maximum rectal tolerable volume ≥240mL (OR=3.14 [1.34-7.54], P=.0082), and abdominal pressure ≥28mmHg (OR=2.75 [1.13-7.33], P=.0248) by multivariate analysis. Obese patients with FI had a comparable severity of FI to that of non-obese patients with FI. Regarding obesity in patients with FI, physicians should focus on stool consistency.

Anorectal Manometry Causing Rectal Perforation: Can We Prevent This Rare Iatrogenic Complication?

Anorectal manometry (ARM) is considered a very safe procedure used to assess anorectal function. ARM induced rectal perforation is exceedingly rare with only 7 reported cases to date. Here, we report an unusual case of rectal perforation caused by ARM. Importantly, there are common features found in previous reports. We propose here an algorithm to help prevent this morbid complication. A 54-yearold Caucasian female with history of rectal adenocarcinoma status post low anterior resection, coloanal anastomosis, loop ileostomy, adjuvant chemoradiation, and rectovaginal fistula repair 3 years prior was referred for ARM as a routine evaluation before ostomy reversal. Gastrograffin enema was normal. Minor resistance was noted during manometry probe insertion. During maximal tolerable volume (MTV) measurement, a “pop” was heard when the balloon was insufflated to 190 cc and the patient experienced minor discomfort. Upon withdrawal, serosanguinous material was noted on the balloon. She tolerated the procedure well otherwise. However, she returned 8 hours later with worsening abdominal pain and chills. Physical examination showed moderate left lower abdominal tenderness without peritoneal signs. CT scan revealed contrast leakage and a large intrapelvic fluid collection, consistent with distal rectal perforation. Meropenem and vancomycin were initiated. CT-guided percutaneous drain was placed and yielded 210 mL of purulent fluid. Her overall clinical status improved with conservative management. Endoscopic evaluation at 3 months showed a completely healed scar just above coloanal anastomosis. She underwent an uneventful ileostomy reversal 4 months after the incident. This case underscores a rare but dreadful complication of ARM. A review of 8 reported cases, including ours, exhibited 3 common features; 1) blood on the balloon upon withdrawal or sudden drop in balloon pressure during insufflation, 2) lower abdominal pain during the procedure, and 3) history of rectal surgery. This triad should prompt an urgent evaluation as suggested in our protocol. We also propose to omit MTV measurement in high-risk patients undergoing routine pre-ostomy reversal evaluation. Risk factors include elderly, history of rectal surgery, and multiple co-morbidities. Conservative treatment can be offered in selected patients while endoscopic closure may be attempted when detected early. The need for surgical intervention should be discussed as a multidisciplinary team.Table 1: Published Data on ARM Causing Rectal PerforationFigure 1

Study of postoperative anorectal dynamics in ultra-low rectal cancer patients undergoing laparoscopic intersphincteric resection

To study postoperative anorectal dynamic change in ultra-low rectal cancer patients undergoing laparoscopic intersphincteric resection. Clinical and follow-up data of 26 ultra-low rectal cancer patients undergoing laparoscopic intersphincteric resection in our department from January 2007 to January 2013 were retrospectively analyzed (observation group). Thirty rectal cancer patients undergoing laparoscopic low anterior resection by the same surgical team in the same period from the Medical Record Room were randomly extracted as control group. The observation indexes included preoperative and postoperative anal resting pressure(ARP), anal maximum squeeze pressure (AMSP), rectal maximum tolerable volume (RMTV), rectal anal inhibition reflex (RAIR) and Wexner anal function scores (0 means normal). There were no significant differences in clinical baseline data between the two groups(all P>0.05), except the distance from lower edge of tumor to dentate line [(2.9±0.4) cm in observation group vs. (5.0±0.5) cm in control group, P=0.000]. There were no differences in preoperative anorectal manometry and Wexner anal function score between two groups (all P>0.05). The average follow-up time in observation group and control group was 14.5 months and 14.0 months respectively. Three months after operation, significant differences between observation group and control group (all P=0.000) were as follows: defecation frequency [(6.0±1.5) times/day vs. (2.5±1.0) times/day], Wexner anal function score(5.0±0.9 vs. 2.9±1.2), ARP [(32.0±6.7) mmHg vs. (45.0±8.2) mmHg], AMSP [(90.1±6.9) mmHg vs. (110.0±7.5) mmHg], RMTV [(61.0±7.2) ml vs. (91.1±7.5) ml] and positive rate of RAIR [11.5%(3/26) vs. 66.7%(20/30)]. One year after surgery, there were no significant differences in defecation frequency, Wexner anal function scores, ARP, AMSP and RMTV between the two groups (all P>0.05), however the difference in positive rate of RAIR was still significant[38.5%(10/26) vs. 93.3%(28/30), P=0.000]. Laparoscopic intersphincteric resection for ultra- low rectal cancer can achieve satisfactory anorectal dynamic effect.

Application of acetone acetals as water scavengers and derivatization agents prior to the gas chromatographic analysis of polar residual solvents in aqueous samples

The sensitivity of gas chromatography (GC) combined with the full evaporation technique (FET) for the analysis of aqueous samples is limited due to the maximum tolerable sample volume in a headspace vial. Using an acetone acetal as water scavenger prior to FET-GC analysis proved to be a useful and versatile tool for the analysis of high boiling analytes in aqueous samples. 2,2-Dimethoxypropane (DMP) was used in this case resulting in methanol and acetone as reaction products with water. These solvents are relatively volatile and were easily removed by evaporation enabling sample enrichment leading to 10-fold improvement in sensitivity compared to the standard 10μL FET sample volumes for a selection of typical high boiling polar residual solvents in water. This could be improved even further if more sample is used. The method was applied for the determination of residual NMP in an aqueous solution of a cefotaxime analogue and proved to be considerably better than conventional static headspace (sHS) and the standard FET approach. The methodology was also applied to determine trace amounts of ethylene glycol (EG) in aqueous samples like contact lens fluids, where scavenging of the water would avoid laborious extraction prior to derivatization. During this experiment it was revealed that DMP reacts quantitatively with EG to form 2,2-dimethyl-1,3-dioxolane (2,2-DD) under the proposed reaction conditions. The relatively high volatility (bp 93°C) of 2,2-DD makes it possible to perform analysis of EG using the sHS methodology making additional derivatization reactions superfluous.

An image-based method to quantify biomechanical properties of the rectum in radiotherapy of prostate cancer

ABSTRACTBackground. Gastrointestinal morbidity after radiotherapy (RT) for prostate cancer may be related to the biomechanical properties of the rectum. In this study we present a magnetic resonance imaging (MRI)-based method to quantitate the thickness and elasticity of the rectal wall in prostate cancer patients treated with RT.Material and methods. Four patients previously treated with RT for prostate cancer underwent an MRI session with stepwise rectal bag deflation (from a maximum tolerable volume to 0 ml, in 50 ml steps), with a probe inserted inside the bag to monitor the internal rectal pressure. MRIs were acquired using Dixon sequences (4 mm axial slice thickness) at each deflation step. Rectal walls were defined from the recto-sigmoid junction to 3 cm above the anal canal as the space between the inner and outer wall surfaces. The wall thickness was determined and biomechanical properties (strain and stress) were calculated from the pressure measurements and the MRI-segmented rectal walls.Results. The integral rectal pressure varied for the maximum tolerable volume (range 150–250 ml) across patients and ranged from 1.3 to 4.0 kPa (SD = 1.2 kPa). Wall thickness was found to vary between patients and also across different rectum segments, with a mean (SD) thickness for the different segments at the 50 ml distension volume of 1.8–4.0 (0.6) mm. Stress showed larger variation than strain, with mean (SD) values for the different segments ranging between 1.5 and 7.0 (1.5) kPa.Conclusion. We have developed a method to quantify biomechanical properties of the rectal wall. The resulting rectal wall thickness, strain and stress differed between patients, as well as across different rectal wall sections. These findings could provide guidance in future predictive outcome modelling in order to better understand the rectal dose-volume response relationship.

Outcomes of ultra-low anterior resection combined with or without intersphincteric resection in lower rectal cancer patients.

We evaluated the current practice of ultra-low anterior resection (uLAR) in patients with lower rectal cancer and compared uLARs using mostly transabdominal approach with or without intersphincteric resection (ISR). A total of 624 consecutive lower rectal cancer patients undergoing curative uLAR were prospectively enrolled as ISR+ vs. ISR- groups (329 vs. 295 patients) between 2005 and 2012. The ISR+ group additionally received levator-sphincter reinforcement after distal resection. The circumferential resection margin (CRM) + rate (≤1 mm) was 2.1 % in the two groups. Postoperative ileus occurred more in the ISR- group than in the ISR+ group (p = 0.02). Substantial erectile dysfunction occurred 1.8 times more frequently in the ISR- group than in the ISR+ group (32 vs. 18.1 %; p = 0.01) among male patients at 2 years postoperatively. The urge to defecate volume and maximal tolerance volume, closely correlated with maximal squeezing pressure and/or mean resting pressure, did not differ between patients with and without chemoradiotherapy until 24 months postoperatively. Nevertheless, the urge to defecate volume was lesser in the ISR- group than in the ISR+ group at 24 months postoperatively (p = 0.022). For 301 patients in which >5 years had elapsed postoperatively, the mean 5-year local recurrence rate was 4.3 %, and the 5-year disease-free and overall survival rates were 78.9 and 92 %, respectively, without differences between the two groups. Compared with uLAR without ISR, the transabdominal ISR with levator-sphincter reinforcement provides a safe resection plane with competent CRM, concurrently reduces substantial complications, and marginally promotes recovery of neorectal function.

Effects of different gracilis loops in graciloplasty on congenital fecal incontinence

To compare the clinical effect of graciloplasty using two different gracilis encircled loops and to research the better method for the treatment of fecal incontinence after anoplasty for imperforate anus. Clinical data of 38 incontinence patients with congenital anal malformation undergoing graciloplasty in our hospitals from January 2009 to January 2012 were retrospectively analyzed. Twenty patients received the modified surgery in which the gracilis muscle was transposed anticlockwise into a circum-anal tunnel with a U-loop and its tendon secured to the ipsilateral pectineal ligament. Eighteen patients received the traditional surgery in which the gracilis muscle was wrapped clockwise around the anus with a γ-loop and its tendon secured to the contralateral periosteum of ischial tuberosity or pectineal ligament. All the patients were evaluated via Wexner score and anal manometry before surgery and 2 weeks, 6 months, 1 year and 2 years after surgery. In addition, it was assessed whether the patients had difficulty defecating while squatting after surgery. Generalized estimating equations showed that the Wexner score in two groups gradually decreased after surgery (P=0.000), but there was no significant difference between two groups (P=0.554). At 2 weeks, 6 months, 1 year and 2 years after surgery, there were respectively 4 cases (20.0%), 3 cases (15.0%), 2 cases (10.0%), 1 case (5.0%), who showed squatting difficult defecation in the U-loop group, and 10 cases (55.6%), 12 cases (66.7%), 10 cases (55.6%), 8 cases (44.4%) in the γ-loop group. The probability of squatting difficult defecation in U-loop group was significantly lower compared to γ-loop group (P=0.002), but the probability of squatting difficult defecation in two groups did not obviously change with time (P=0.057). Repeated measures ANOVA showed that anal resting pressure, anal maximal squeeze pressure, duration of anal squeeze, and rectal maximum tolerable volume in two groups were gradually improved after surgery (all P<0.01), but there were no significant differences between two groups (all P>0.05). Graciloplasty with different gracilis loops can improve anal function. However, U-loop can better improve difficult defecating while squatting, and is worthwhile for spreading in clinical practice.

Accuracy and Reproducibility of High-definition Anorectal Manometry and Pressure Topography Analyses in Healthy Subjects

High-definition anorectal manometry (HDAM-3D) provides a topographic and 3-dimensional profile of anorectal pressure. We assessed anorectal sensorimotor function and the reproducibility of measurements made with HDAM-3D in healthy adults, and the accuracy of data analysis by its software. Anal sphincter pressures and rectal sensory thresholds were measured in 78 healthy subjects via placement of a 10-mm rigid probe, with 256 circumferentially arrayed pressure sensors, and a balloon in the rectum. The bearing down maneuver was assessed in a subset of 18 subjects. We compared data analyzed by an expert with findings from automated software analysis. Measurements made in a subset of 16 subjects, 2 weeks apart, were compared to determine reproducibility. Resting, squeezing, and sustained squeezing pressures were significantly higher in men than in women (P < .05); other parameters were similar. Desire and urgency to defecate were similar between men and women, but the maximal tolerable volume was significantly lower in women (P < .05). Older women (>50 years) had significantly lower resting (P < .01) and sustained squeeze pressures (P < .04). Dyssynergic patterns of defecation were observed in 12 of 18 subjects (67%) who attempted to defecate without the 60-mL rectal balloon distention and in 6 of 18 subjects (33%) with the 60-mL rectal balloon distention. Test-retest values correlated (r= 0.81), as did analyses made by an expert vs software analyses of data (r= 0.99). On the basis of HDAM-3D measurements in healthy adults, anal sphincter pressures are higher in men than in women, but sensory and other parameters are similar; older subjects have weaker sphincters. Many people were found to have dyssynergic patterns of defecation, which could be related to the probe or other technical issues, so this technique may not be suitable for assessing defecation patterns. Measurements made by HDAM-3D are reproducible, and data can be accurately analyzed by its software.

Ameliorating Effect of Transcutaneous Electroacupuncture on Impaired Gastric Accommodation in Patients with Postprandial Distress Syndrome-Predominant Functional Dyspepsia: A Pilot Study.

Patients with functional dyspepsia (FD) have both reduced gastric accommodation and impaired gastric motility that are difficult to treat. The aim of this study was to investigate the therapeutic potential of transcutaneous electroacupuncture (TEA) for both of these disorders in FD patients. Acute experiments were performed in FD patients to study the effect of TEA and sham-TEA on gastric accommodation assessed by a nutrient drink test and gastric motility assessed by the measurement of the electrogastrogram (EGG). TEA or sham-TEA was performed via cutaneous electrodes at acupoints ST36 and PC6 or sham-points nonacupoints. It was found that (1) gastric accommodation (maximum tolerable volume) was reduced in FD patients compared with the controls (P < 0.03). TEA improved gastric accommodation in FD patients (P < 0.02). (2) Acute TEA significantly increased the percentage and power of normal gastric slow waves in the fed state assessed in the FD patients by the EGG in comparison with sham-TEA. (3) TEA increased vagal activity assessed by the spectral analysis of the heart rate variability in the fed state in FD patients. It was concluded that needleless method of transcutaneous electroacupuncture may have a therapeutic potential for treating both impaired gastric accommodation and impaired gastric motility in patients with FD.

Temporary sacral nerve stimulation in patients with fecal incontinence owing to rectal hyposensitivity: A prospective, double-blind study

Rectal hyposensitivity (RH) can lead to fecal incontinence (FI). Sacral nerve stimulation (SNS) is known to modulate rectal sensation, but no data about affecting FI owing to RH are available. This prospective study aimed to assess the therapeutic effect of temporary SNS on patients with FI owing to RH. Twenty-four patients with FI owing to RH had temporary SNS (4 weeks on followed by 1 week off). Before SNS (baseline), after 4 weeks of stimulation (on), and at the end of the off week we recorded first constant sensation (FCS), defecatory desire volume (DDV), maximum tolerated volume (MTV), anal pressures, bowel diaries, Wexner incontinence score, and FI quality-of-life score (FIQOL). There were significant decreases in DDV and MTV during the on-treatment period (P < .0001); this decrease was not significant during the off period. FCS was not significantly affected by SNS. FI episodes significantly improved during the on period in 22 patients (from 5.3 to 1.1 per week; P < .0001) and mean Wexner incontinence score improved from 13.3 to 1.7 (P < .0001). Anal pressures (resting and squeeze) significantly increased during the on period but not during the off period. There was significant improvement in FIQOL during the on period only. SNS can be effective in restoring continence and improving QOL in patients with FI owing to RH. Improved continence might be related to improvement of rectal sensation and/or increased anal pressure. The washout effect of SNS on the continence score, DDV, and MTV after cessation of stimulation needs to be explained.