Colonic J-pouch versus side-to-end anastomosis for rectal cancer: a systematic review and meta-analysis of randomized controlled trials

Reconstructive techniques following low anterior resection for carcinoma of the rectum

INTRODUCTION

Multiple reconstructive techniques have been described for reconstruction after a low anterior resection for carcinoma rectum. Colonic J pouch (CJP), Side to end anastomosis (SEA), transverse coloplasty pouch (TCP) and Straight Colo-rectal/anal anastomosis were the most widely studied.

EVIDENCE ACQUISITION

PubMed, Embase and Cochrane data base were searched for randomized, non-randomized studies and systematic reviews from inception of the databases till July 31st, 2023.

EVIDENCE SYNTHESIS

Considerable heterogeneity existed among different study findings. Reservoir techniques, including CJP, SEA, and TCP, exhibited reduced stool frequency, decreased urgency, and improved continence status compared to SCA, particularly in the short term. CJP maintained this advantage into the intermediate term. Other functional outcomes were similar among the techniques. However, these functional improvements did not translate into enhanced Quality of Life (QoL). TCP was associated with an elevated risk of anastomotic leaks. Other surgical outcomes remained comparable across all four techniques. Sexual outcomes also exhibited no significant variation. Some studies suggested that the size of the side limb in CJP or SEA may not significantly impact functional outcomes, implying that neorectum capacity may not be the primary determinant of improved function. The precise physiological mechanism underlying these findings remains unknown.

CONCLUSIONS

In the short and intermediate terms, reservoir techniques demonstrated superior functional outcomes, but long-term performance was comparable among all techniques. Notably, enhanced functional outcomes did not translate to improved Quality of Life. TCP, while effective, is linked to an increased risk of anastomotic complications, necessitating cautious utilization.

Comparison of the Colonic J-Pouch Versus Side-To-End Anastomosis Following Low Anterior Resection: A Systematic Review and Meta-Analysis

BACKGROUND

The aim of this systematic review and meta-analysis is to evaluate clinical, functional, and anorectal physiology outcomes of the side-to-end vs colonic J-pouch (CJP) anastomosis following anterior resection for rectal cancer.

METHODS

A PRISMA-compliant systematic review and meta-analysis was conducted using multiple electronic databases and clinical trial registers and all studies comparing side-to-end vs CJP anastomosis were included. Peri-operative complications, mortality rate, functional bowel, and anorectal outcomes were evaluated.

RESULTS

Eight randomized controlled trials (RCTs) and two observational studies with 1125 patients (side-to-end: n = 557; CJP: n = 568) were included. Of the entire functional bowel outcome parameters analyzed, only the sensation of incomplete bowel evacuation was significant in the CJP group at 6 months [OR: 2.07; 95% CI 1.06 - 4.02, P = .03]. Peri- and post-operative clinical parameters were comparable in both groups (total operative time, intra-operative blood loss, anastomotic leak rate, return to theater, anastomotic stricture formation and mortality). Equally, most of the analyzed anorectal physiology parameters (anorectal volume, anal squeeze pressure, maximum anal volume) were not significantly different between the two groups. However, anal resting pressure (mmHg) 2 years post-operatively was noted to be significantly higher in the side-to-end group than that of the CJP configuration [MD: -8.76; 95% CI - 15.91 - 1.61, P = .02].

DISCUSSION

Clinical and functional outcomes following CJP surgery and side-to-end coloanal anastomosis are comparable. Neither technique appears to proffer solution to low anterior resection syndrome in the short term but future well-designed; high-quality RCTs with long term follow-up are required.

Preventative strategies for low anterior resection syndrome

BACKGROUND

A common and debilitating complication of low anterior resection for rectal cancer is low anterior resection syndrome (LARS). As a multifactorial entity, LARS is poorly understood and challenging to treat. Despite this, prevention strategies are commonly overlooked. Our aim was to review the pathophysiology of LARS and explore current evidence on the efficacy and feasibility of prophylactic techniques.

METHODS

A literature review was performed between [1st January 2000 to 1st October 2023] for studies which investigated preventative interventions for LARS. Mechanisms by which LARS develop are described, followed by a review of prophylactic strategies to prevent LARS. Medline, Cochrane, and PubMed databases were searched, 189 articles screened, 8 duplicates removed and 18 studies reviewed.

RESULTS

Colonic dysmotility, anal sphincter dysfunction and neorectal dysfunction all contribute to the development of LARS, with the complex mechanism of defecation interrupted by surgery. Transanal irrigation (TAI) and pelvic floor rehabilitation (PFR) have shown benefits in preventing LARS, but may be limited by patient compliance. Intraoperative nerve monitoring (IONM) and robotic-assisted surgery have shown some promise in surgically preventing LARS. Nerve stimulation and other novel strategies currently used in treatment of LARS have yet to be investigated in their roles prophylactically.

CONCLUSIONS

To date, there is a limited evidence base for all preventative strategies including IONM, RAS, PFP and TAI. These strategies are limited by either access (IONM, RAS and PFP) or acceptability (PFP and TAI), which are both key to the success of any intervention. The results of ongoing trials will serve to assess acceptability, while technological advancement may improve access to some of the aforementioned strategies.

Risk factors for ischemia/necrosis of the colonic stump after proctectomy and delayed coloanal anastomosis

INTRODUCTION

Delayed coloanal anastomosis (DCAA) is a two-stage procedure. DCAA has been increasingly reused in recent years in the management of rectal cancer. Such increased use of DCAA has highlighted the complications associated with this procedure. We aimed to evaluate the risk and risk factors of ischemia/necrosis of the colonic stump between the two stages of DCAA.

PATIENTS AND METHODS

All patients who underwent a proctectomy with a DCAA were included in this retrospective single-centre study from November 2012 to June 2022. Two groups of patients were defined: patients with a well vascularized colonic stump (well vascularized group) and those who experienced ischemia or necrosis of the colonic stump (ischemic group). The primary endpoint was the rate of ischemia or necrosis of the colonic stump and an evaluation of the associated risk factors.

RESULTS

During the study period, 43 patients underwent DCAA. Amongst them, 32 (75%) had a well-vascularized colonic stump (well-vascularized group) and 11 (25%) ischemia of the colonic stump (ischemic group). Relative to patients in the well-vascularized group, those in the ischemic group were more often men (81.8% vs 40.6%, p = 0.034), had a higher BMI (29.2 kg/m2 vs 25.7 kg/m2, p = 0.03), were more frequently diabetic (63.6% vs 21.9%, p = 0.01) and more frequently had had preoperative radiotherapy (100% vs 53.1%, p = 0.008). On the preoperative CT scan, the interspinous diameter was shorter in the ischemic group (9.4 ± 1.01 cm vs 10.6 ± 1.01 cm, p = 0.001), the intertuberosity diameter was shorter (9.2 ± 1.18 cm vs 11.9 ± 1.18 cm, p < 0.0001), and the length of the anal canal was longer (31.9 ± 3 mm vs 27.4 ± 3.2 mm, p < 0.0001).

CONCLUSION

This study highlights clear risk factors for ischemia/necrosis of the colonic stump after proctectomy with DCAA.

Pathologic complete response to TNT + camrelizumab for rectal cancer with surgical anus-preservation: case report and literature review

Background

This case report demonstrates the efficacy of total neoadjuvant therapy (TNT) based on pathological complete response (PCR). We also discuss the surgical approach to preserving the anus and its perioperative management.

Case presentaion

The patient was a 26-year-old woman, with blood in the stool and stool thinning for over two months. Preoperative examination revealed locally advanced rectal cancer invading the left anal raphe and enlarged lymph nodes adjacent to the left internal iliac vessels. The lesion was preoperatively classified as T4bN1bM0 IIIC. Considering the size and depth of the tumor, it was difficult to have sufficient margins for radical resection, and the tumor was too close to the anal orifice. Considering the patient's youth and strong desire to preserve the anus, it was decided to use TNT combined with a camrelizumab regimen. After the entire course of neoadjuvant radiotherapy, the tumor size significantly reduced in fibrotic manifestations, and no enlargement of the lymph nodes adjacent to the left internal iliac vessels was observed. She underwent robotic laparoscopic ultra-low anterior rectal resection, left lateral lymph node dissection, and temporary ileostomy, and no significant residue was observed after all bowel tubes were taken for examination, nor was there cancerous involvement at the distal or radial cut edges, or metastasis. The patient was discharged nine days postoperatively, and no major complications were detected. Follow-up was performed without adjuvant chemotherapy.

Conclusions

TNT may be a better surgical option for preserving the anus and for complete radical resection in patients with LARC for whom Miles' resection is indicated.

Comparison of complications and bowel function among different reconstruction techniques after low anterior resection for rectal cancer: a systematic review and network meta-analysis

BACKGROUND

Anastomosis for gastrointestinal reconstruction has been contentious after low anterior resection of rectal cancer for the past 30 years. Despite the abundance of randomized controlled trials (RCTs) on colon J-pouch (CJP), straight colorectal anastomosis (SCA), transverse coloplast (TCP), and side-to-end anastomosis (SEA), most studies are small and lack reliable clinical evidence. We conducted a systematic review and network meta-analysis to evaluate the effects of the four anastomoses on postoperative complications, bowel function, and quality of life in rectal cancer.

METHODS

We assessed the safety and efficacy of CJP, SCA, TCP, and SEA in adult patients with rectal cancer after surgery by searching the Cochrane Library, Embase, and PubMed databases to collect RCTs from the date of establishment to May 20, 2022. Anastomotic leakage and defecation frequency were the main outcome indicators. We pooled data through a random effects model in a Bayesian framework and assessed model inconsistency using the deviance information criterion (DIC) and node-splitting method and inter-study heterogeneity using the I-squared statistics (I²). The interventions were ranked according to the surface under the cumulative ranking curve (SUCRA) to compare each outcome indicator.

RESULTS

Of the 474 studies initially evaluated, 29 were eligible RCTs comprising 2631 patients. Among the four anastomoses, the SEA group had the lowest incidence of anastomotic leakage, ranking first (SUCRA_SEA = 0.982), followed by the CJP group (SUCRA_CJP = 0.628). The defecation frequency in the SEA group was comparable to those in the CJP and TCP groups at 3, 6, 12, and 24 months postoperatively. In comparison, the defecation frequency in the SCA group 12 months after surgery all ranked fourth. No statistically significant differences were found among the four anastomoses in terms of anastomotic stricture, reoperation, postoperative mortality within 30 days, fecal urgency, incomplete defecation, use of antidiarrheal medication, or quality of life.

CONCLUSIONS

This study demonstrated that SEA had the lowest risk of complications, comparable bowel function, and quality of life compared to the CJP and TCP, but further research is required to determine its long-term consequences. Furthermore, we should be aware that SCA is associated with a high defecation frequency.

The impact of the anastomotic configuration on low anterior resection syndrome 3 years after total mesorectal excision for rectal cancer: a national cohort study

AIM

After low anterior resection, the bowel can be anastomosed in different ways. It is not clear which configuration is optimal from a functional and complication point of view. The primary aim was to investigate the impact of the anastomotic configuration on bowel function evaluated by the low anterior resection syndrome (LARS) score. Secondarily, the impact on postoperative complications was evaluated.

METHOD

All patients who had undergone low anterior resection from 2015 to 2017 were identified in the Swedish Colorectal Cancer Registry. Three years after surgery, patients were sent an extensive questionnaire and were analysed based on anastomotic configuration ('J-pouch/side-to-end anastomosis' or 'straight anastomosis'). Inverse probability weighting by propensity score was used to adjust for confounding factors.

RESULTS

Among 892 patients, 574 (64%) responded, of whom 494 patients were analysed. After weighting, the anastomotic configuration had no significant impact on the LARS score (J-pouch/side-to-end OR 1.05, 95% confidence interval [CI] 0.82-1.34). The J-pouch/side-to-end anastomosis was significantly associated with overall postoperative complications (OR 1.43, 95% CI 1.06-1.95). No significant difference was seen regarding surgical complications (OR 1.14, 95% CI 0.78-1.66).

CONCLUSION

This is the first study investigating the impact of the anastomotic configuration on long-term bowel function, evaluated by the LARS score, in an unselected national cohort. Our results suggested no benefit for J-pouch/side-to-end anastomosis on long-term bowel function and postoperative complication rates. The anastomotic strategy may be based upon the anatomical conditions of the patient and surgical preference.

Reconstructive techniques following low anterior resection for carcinoma of the rectum: meta-analysis

BACKGROUND

Multiple trials have compared reconstruction techniques used following the resection of distal rectal cancers, including straight colorectal anastomosis (SCA), colonic J pouch (CJP), side-to-end anastomosis (SEA), and transverse coloplasty (TCP). The latest meta-analysis on the subject concluded that all the reservoir techniques produce equally good surgical and functional outcomes compared with SCA. Numerous trials have been published in this regard subsequently. Hence, a network analysis (NMA) was performed to rank these techniques.

METHODS

A literature search of MEDLINE, Embase, and the Cochrane Library from their inception until April 2021 was conducted to identify randomized trials. Functional and surgical outcome data were pooled. ORs and standardized mean differences (MDs) were used as pooled effect size measures. A frequentist NMA model was used.

RESULTS

Thirty-two trials met the eligibility criteria comprising 3072 patients. CJP showed better functional outcomes, such as low stool frequency and better incontinence score, both in the short term (stool frequency, MD -2.06, P < 0.001; incontinence, MD -1.17, P = 0.007) and intermediate term (stool frequency, MD -0.81, P = 0.021; incontinence MD -0.56, P = 0.083). Patients with an SEA (long-term OR 4.37; P = 0.030) or TCP (long-term OR 5.79; P < 0.001) used more antidiarrheal medications constantly. The urgency and sensation of incomplete evacuation favoured CJP in the short term. TCP was associated with a higher risk of anastomotic leakage (OR 12.85; P < 0.001) and stricture (OR 3.21; P = 0.012).

CONCLUSION

Because of its better functional outcomes, CJP should be the reconstruction technique of choice. TCP showed increased anastomotic leak and stricture rates, warranting judicious use.

[Colonic pouch reconstruction after low anterior rectal resection]

For many decades the coloanal anastomosis was traditionally created as an end-to-end anastomosis. Despite successful surgical restoration of the intestinal passage after low rectal resection and total mesorectal excision (TME), physiological continence and evacuation function cannot be achieved in many cases using end-to-end anastomosis. Subsequent complaints, such as fecal incontinence and urge problems, evacuation difficulties and high stool frequency (so-called low anterior resection syndrome, LARS) are the result. The combination of symptoms after TME known as LARS is described in the literature in up to 60% of cases. The increased occurrence of the imperative urge to defecate, frequent bowel movements and problems with fecal incontinence motivated surgeons to look for alternative anastomosis techniques. Side-to-end anastomosis, coloplasty pouch and colonic J‑pouch have been shown in various studies to be superior to end-to-end anastomosis in terms of functional results. Current studies could show that the side-to-end anastomosis (even if this is not a pouch in the actual sense) and the two pouch techniques show comparable results in terms of functional outcome and the rate of anastomotic leakage. The alternative to coloanal anastomosis after TME is the abdominoperineal resection. Most, especially younger patients, prefer to try to maintain continence with the risk of the described functional problems. If the patients are well selected, TME can be carried out with the current techniques in such a way that continuity is maintained and a good defecation function is achieved for a large proportion of patients using the pouch-anal anastomosis or the side-to-end techniques.

The role of colonic motility in low anterior resection syndrome

Low anterior resection syndrome (LARS) describes the symptoms and experiences of bowel dysfunction experienced by patients after rectal cancer surgery. LARS is a complex and multifactorial syndrome exacerbated by factors such as low anastomotic height, defunctioning of the colon and neorectum, and radiotherapy. There has recently been growing awareness and understanding regarding the role of colonic motility as a contributing mechanism for LARS. It is well established that rectosigmoid motility serves an important role in coordinating rectal filling and maintaining continence. Resection of the rectosigmoid may therefore contribute to LARS through altered distal colonic and neorectal motility. This review evaluates the role of colonic motility within the broader pathophysiology of LARS and outlines future directions of research needed to enable targeted therapy for specific LARS phenotypes.

Comparison of the colonic J-pouch versus straight (end-to-end) anastomosis following low anterior resection: a systematic review and meta-analysis

AIMS

To evaluate comparative outcomes of straight (end-to-end) anastomosis versus colonic J-pouch anastomosis following anterior resection.

METHODS

A systematic search of multiple electronic data sources was conducted, and all studies comparing straight (end-to-end) anastomosis versus J-pouch anastomosis were included. Anastomotic complications, post-operative complications, re-operation, mortality, and functional outcomes were the evaluated outcome parameters. Revman 5.3 was used for data analysis.

RESULTS

Twenty-seven studies reporting a total number of 3293 patients who underwent straight anastomosis (n = 1581) or J-pouch (n = 1712) were included. Anastomotic leak and re-operation rates were significantly higher in the straight group compared to the J-pouch group [RD 0.03, P = 0.03] and [OR 1.87, P = 0.003], respectively. Stool frequency per 24 h at 6 months and 12 months was lower in the J-pouch group than the straight group [MD 2.13, P = 0.003] and [MD 1.44, P = 0.00001], respectively. In addition, the use of anti-diarrheal medication is lower at 12 months in the J-pouch group [MD 3.85, P = 0.03]. Moreover, the two groups showed comparable results regarding SSI, sepsis, paralytic ileus, anastomotic stricture formation, anastomotic bleeding, and mortality.

CONCLUSION

J-pouch anastomosis showed lower risk for anastomotic leak and re-operation. Furthermore, better functional outcomes such as stool frequency were achieved using the colonic J-pouch reconstruction over the conventional straight end-to-end anastomosis.