Safety and efficacy of side-to-end anastomosis versus colonic J-pouch anastomosis in sphincter-preserving resections: an updated 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.

Surgical considerations for the "perfect" colorectal anastomosis

A technically sound colorectal anastomosis is paramount in optimising outcomes and reducing complications such as anastomotic leak which can lead to prolonged hospital stay, repeated operations, stoma formation, anastomotic stricture formation and even mortality in patients. Therefore, thorough consideration should be given to all aspects of its construct, from its basic mechanical configuration to subsequent evaluation of anastomosis integrity and perfusion. Risk factors for anastomotic leakage are well established and are usually classified into modifiable and non-modifiable risk factors. In this review article, we will focus on and discuss the modifiable surgical risk factors and how the authors incorporate latest evidence and surgical principles in creating a "perfect" colorectal anastomosis. We review the latest evidence on the proper mechanical construct of a colorectal anastomosis, enhanced recovery after surgery (ERAS), high versus low ligation of inferior mesenteric artery (IMA), routine splenic flexure mobilisation (SFM), the use of indocyanine green (ICG), as well as methods used for the evaluation of the anastomosis integrity. New adjuncts described in the literature to reinforce anastomoses are also discussed. In summary, meticulous technique with nuanced refinements based on our understanding of surgical principles, together with the adoption of relevant new technologies, are essential in our strive towards the "perfect" colorectal anastomosis.

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.

Coloanal Anastomosis

The furthest extent of restorative proctectomy involves a colon to anal anastomosis in the deep pelvis. While the anastomosis can be challenging, it can allow the patient to avoid a permanent ostomy. Patient and surgeon preparation can improve patient outcomes. This article will describe the options, technical challenges, and anecdotal tips for coloanal anastomosis.

The Colorectal Anastomosis: A Timeless Challenge

Colorectal anastomosis is a sophisticated problem that demands an elaborate discussion and an elegant solution. "Those who forget the past are condemned to repeat it." George Santayana, Life of Reason , 1905.

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.

Surgical Treatment of Low-Lying Rectal Cancer: Updates

Despite innovative advancements, distally located rectal cancer remains a critical disease of challenging management. The crucial location of the tumor predisposes it to a circumferential resection margin (CRM) that tends to involve the anal sphincter complex and surrounding organs, with a high incidence of delayed anastomotic complications and the risk of the pelvic sidewall or rarely inguinal lymph node metastases. In this regard, colorectal surgeons should be aware of other issues beyond total mesorectal excision (TME) performance. For decades, the concept of extralevator abdominoperineal resection to avoid compromised CRM has been introduced. However, the complexity of deep pelvic dissection with poor visualization in low-lying rectal cancer has led to transanal TME. In contrast, neoadjuvant chemoradiotherapy (NCRT) has allowed for the execution of more sphincter-saving procedures without oncologic compromise. Significant tumor regression after NCRT and complete pathologic response also permit applying the watch-and-wait protocol in some cases, now with more solid evidence. This review article will introduce the current surgical treatment options, their indication and technical details, and recent oncologic and functional outcomes. Lastly, the novel characteristics of distal rectal cancer, such as pelvic sidewall and inguinal lymph node metastases, will be discussed along with its tailored and individualized treatment approach.

Nomogram to predict postoperative infectious complications after surgery for colorectal cancer: a retrospective cohort study in China

Background

Postoperative infectious complications (ICs) after surgery for colorectal cancer (CRC) increase in-hospital deaths and decrease long-term survival. However, the methodology for IC preoperative and intraoperative risk assessment has not yet been established. We aimed to construct a risk model for IC after surgery for CRC.

Methods

Between January 2016 and June 2020, a total of 593 patients who underwent curative surgery for CRC in Chengdu Second People’s Hospital were enrolled. Preoperative and intraoperative factors were obtained retrospectively. The least absolute shrinkage and selection operator (LASSO) method was used to screen out risk factors for IC. Then, based on the results of LASSO regression analysis, multivariable logistic regression analysis was performed to establish the prediction model. Bootstraps with 300 resamples were performed for internal validation. The performance of the model was evaluated with its calibration and discrimination. The clinical usefulness was assessed by decision curve analysis (DCA).

Results

A total of 95 (16.0%) patients developed ICs after surgery for CRC. Chronic pulmonary diseases, diabetes mellitus, preoperative and/or intraoperative blood transfusion, and longer operation time were independent risk factors for IC. A prediction model was constructed based on these factors. The concordance index (C-index) of the model was 0.761. The calibration curve of the model suggested great agreement. DCA showed that the model was clinically useful.

Conclusion

Several risk factors for IC after surgery for CRC were identified. A prediction model generated by these risk factors may help in identifying patients who may benefit from perioperative optimization.