High ligation of the inferior mesenteric artery and anastomotic leakage in anterior resection for rectal cancer: a systematic review and meta-analysis of randomized controlled trial studies

[Anastomotic leaks in colorectal surgery]

A leakage of a colorectal anastomosis represents a severe complication in visceral surgery. An anastomotic insufficiency (AI) is a potentially life-threatening complication for patients that carries a high risk of subsequent complications and long-term stoma care. Numerous factors influence the risk of AI. Knowing and being able to estimate these factors are essential for successful treatment in colorectal surgery as they help determine the surgical strategy. The recognition of an AI can be challenging for practitioners due to the variability in the clinical presentation. If the presence of AI is suspected appropriate diagnostic measures must therefore be taken. If an AI has occurred a colorectal specialist should definitely be involved in the treatment as this can significantly reduce further complications and the rate of permanent stomas.

Long-term clinical outcomes after high and low ligations with lymph node dissection around the root of the inferior mesenteric artery in patients with rectal cancer

PURPOSE

This study aimed to evaluate the long-term clinical outcomes based on the ligation level of the inferior mesenteric artery (IMA) in patients with rectal cancer.

METHODS

This was a retrospective analysis of a prospectively collected database that included all patients who underwent elective low anterior resection for rectal cancer between January 2013 and December 2019. The clinical outcomes included oncological outcomes, postoperative complications, and functional outcomes. The oncological outcomes included overall survival (OS) and relapse-free survival (RFS). The functional outcomes, including defecatory and urogenital functions, were analyzed using the Fecal Incontinence Severity Index, International Prostate Symptom Score, and International Index of Erectile Function questionnaires.

RESULTS

In total, 545 patients were included in the analysis. Of these, 244 patients underwent high ligation (HL), whereas 301 underwent low ligation (LL). The tumor size was larger in the HL group than in the LL group. The number of harvested lymph nodes (LNs) was higher in the HL group than in the LL group. There were no significant differences in complication rates and recurrence patterns between the groups. There were no significant differences in 5-year RFS and OS between the groups. Cox regression analysis revealed that the ligation level (HL vs. LL) was not a significant risk factor for oncological outcomes. Regarding functional outcomes, the LL group showed a significant recovery in defecatory function 1 year postoperatively compared with the HL group.

CONCLUSION

LL with LNs dissection around the root of the IMA might not affect the oncologic outcomes comparing to HL; however, it has minimal benefit for defecatory function.

Inferior Mesenteric Artery Ligation Level in Rectal Cancer Surgery beyond Conventions: A Review

Within the intricate field of rectal cancer surgery, the contentious debate over the optimal level of ligation of the inferior mesenteric artery (IMA) persists as an ongoing discussion, influencing surgical approaches and patient outcomes. This narrative review incorporates historical perspectives, technical considerations, and functional as well as oncological outcomes, addressing key questions related to anastomotic leakage risks, genitourinary function, and oncological concerns, providing a more critical understanding of the well-known inconclusive evidence. Beyond the dichotomy of high versus low tie, it navigates the complexities of colorectal cancer surgery with a fresh perspective, posing a transformative question: "Is low tie ligation truly reproducible?" Considering a multidimensional approach that enhances patient outcomes by integrating the surgeon, patient, technique, and technology, instead of a rigid and categorical statement, we argued that a balanced response to this challenging question may require compromise.

Splenic flexure mobilization and anastomotic leakage in anterior resection for rectal cancer: A multicentre cohort study

BACKGROUND AND OBJECTIVE

Some colorectal surgeons advocate routine splenic flexure mobilization (SFM) when performing anterior resection for rectal cancer to ensure a tension-free anastomosis. Meta-analyses of smaller studies suggest that this approach does not influence anastomotic leakage rates, but larger multicentre studies are needed to confirm the safety of a selective strategy. The aim of this study is to evaluate the impact of SFM on anastomotic leakage.

METHODS

This is a retrospective multicentre cohort study, comprising 1109 patients operated with anterior resection for rectal cancer in 2014-2018. Exposure was SFM, while anastomotic leakage within a year constituted the outcome. Stratified analyses were performed for type of mesorectal excision and surgical approach, as well as sensitivity analysis considering vascular tie placement. Multivariable Cox regression with hazard ratios (HRs) and 95% confidence intervals (CIs) was employed to adjust for confounding, while multiple imputation was used for missing data.

RESULTS

SFM was performed in 381 patients (34.4%). Anastomotic leakage occurred in 83 (21.8%) and 123 (20.3%) patients operated with and without SFM, respectively. SFM was neither clearly detrimental nor beneficial regarding anastomotic leakage (adjusted HR = 0.82; 95% CI: 0.59-1.15), with no apparent differences for total or partial mesorectal excision and minimally invasive or open surgery. Concurrent high vascular ligation did not impact these results, and there was no evidence of interaction from centers with a more common use of SFM.

CONCLUSIONS

SFM did not seem to influence the risk of anastomotic leakage after anterior resection for rectal cancer, regardless of type of mesorectal excision, use of minimally invasive surgery, or high vascular ligation.

Comparison of the short-term and long-term outcomes of three different types of inferior mesenteric artery ligation in left colonic and rectal cancers: a network meta-analysis

To perform a network meta-analysis of the literature to assess the short-term and long-term outcomes of three operations for left colon and rectal cancer. Electronic literature searches were performed in the PubMed, Web of Science, EMBASE, and Cochrane Central Register of Controlled Trials databases up to August 2022. A Bayesian network meta-analysis using R software, ADDIS, and Review Manager 5.4 was conducted to compare outcomes of high ligation of the inferior mesenteric artery(IMA),low ligation of the IMA with D2 dissection (LLD2), and low ligation of the IMA with D3 dissection (LLD3). Sensitivity analysis was applied to investigate the influence of each primary study on the final result of the meta-analysis. Asymmetry of data was estimated by using Egger's tests. Publication bias corrected by trimming and filling method. A total of 44 studies, 5 randomized clinical trials (RCTs) and 39 non-RCTs, were included in this meta-analysis. HL was associated with a higher risk of anastomotic leakage (HL vs. LLD2, OR = 1.35, 95% CI 1.13-3.25, P = 0.001; HL vs. LLD3, OR = 1.65, 95% CI 1.35-2.01, P < 0.001), and required a longer postoperative hospital stay (HL vs. LLD3, SMD = 0.28, 95%CI 0.09-0.48, P = 0.01).However HL showed an advantage in terms of operation time(HL vs. LLD3, SMD = - 0.13, 95%CI - 0.26 to 0.01, P = 0.04). LLD3 is most likely to rank best in terms of short-term and long-term outcomes after surgery for left colon and rectal cancer. Caution should be taken in the risk of anastomotic leakage when treating colorectal cancer with LLD2. HL, LLD2 and LLD3 provide similar overall survival rates for left colon and rectal cancer.

Inferior mesenteric artery ligation level in rectal cancer surgery: still no answer-a systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis is to summarize the current scientific evidence regarding the impact of the level of inferior mesenteric artery (IMA) ligation on post-operative and oncological outcomes in rectal cancer surgery.

METHODS

We conducted a systematic review of the literature up to 06 September 2022. Included were RCTs that compared patients who underwent high (HL) vs. anterior (LL) IMA ligation for resection of rectal cancer. The literature search was performed on Medline/PubMed, Scopus, and the Web of Science without any language restrictions. The primary endpoint was overall anastomotic leakage (AL). Secondary endpoints were oncological outcomes, intraoperative complications, urogenital functional outcomes, and length of hospital stay.

RESULTS

Eleven RCTs (1331 patients) were included. The overall rate of AL was lower in the LL group, but the difference was not statistically significant (RR 1.43, 95% CI 0.95 to 2.96). The overall number of harvested lymph nodes was higher in the LL group, but the difference was not statistically significant (MD 0.93, 95% CI - 2.21 to 0.34). The number of lymph nodes harvested was assessed in 256 patients, and all had a laparoscopic procedure. The number of lymph nodes was higher when LL was associated with lymphadenectomy of the vascular root than when IMA was ligated at its origin, but there the difference was not statistically significant (MD - 0.37, 95% CI - 1.00 to 0.26). Overall survival at 5 years was slightly better in the LL group, but the difference was not statistically significant (RR 0.98, 95% CI 0.93 to 1.05). Disease-free survival at 5 years was higher in the LL group, but the difference was not statistically significant (RR 0.97, 95% CI 0.89 to 1.04).

CONCLUSIONS

There is no evidence to support HL or LL according to results in terms of AL or oncologic outcome. Moreover, there is not enough evidence to determine the impact of the level of IMA ligation on functional outcomes. The level of IMA ligation should be chosen case by case based on expected functional and oncological outcomes.

Real-time semi-quantitative assessment of anastomotic blood perfusion in mini‑invasive rectal resections by Sidestream Dark Field (SDF) imaging technology: a prospective in vivo pilot study

PURPOSE

Anastomotic leakage (AL) is one of the severe complications after rectal surgery, and anastomotic ischemia is one of the main factors. This prospective in vivo pilot study aimed to evaluate the effectiveness of Sidestream Dark Field (SDF) imaging in quantitative assessment of anastomotic microcirculation and to analyze its correlation with AL.

METHODS

Thirty-three patients with rectal cancer who underwent laparoscopic low anterior resection from 2019 to 2020 were enrolled. Microcirculation was measured by SDF imaging at the descending colon, the mesocolon transection line (MTL), and 1 cm and 2 cm distal to the MTL. Anastomotic microcirculation was measured at the stapler anvil edge before anastomosis. Quantitative perfusion-related parameters were as follows: microcirculation flow index (MFI), perfused vessel density (PVD), proportion of perfused vessels (PPV), and total vessel density (TVD).

RESULTS

All patients obtained stable microcirculation images. Functional microcirculation parameters (MFI, PPV, PVD) decreased successively from the descending colon, the colon at MTL, and 1 cm and 2 cm distal to the MTL (all P < 0.01). Extremely poor microcirculation was found at the intestinal segment 2 cm distal to the MTL. Micro-perfusion was significantly lower at the colonic limb of the anastomosis compared with the descending colon (all P < 0.001). Anastomotic leakage occurred in 3 patients (9.1%) whose anastomotic microcirculation was significantly lower than those without AL (all P < 0.01). Blood perfusion at the colonic limb of the anastomosis was significantly higher in patients with left colic artery preservation than in controls.

CONCLUSION

SDF imaging is a promising technique for evaluating anastomotic microcirculation and has potential clinical significance for risk stratification of AL.

Predictive Factors for Anastomotic Leakage Following Colorectal Cancer Surgery: Where Are We and Where Are We Going?

Anastomotic leakage (AL) remains one of the most severe complications following colorectal cancer (CRC) surgery. Indeed, leaks that may occur after any type of intestinal anastomosis are commonly associated with a higher reoperation rate and an increased risk of postoperative morbidity and mortality. At first, our review aims to identify specific preoperative, intraoperative and perioperative factors that eventually lead to the development of anastomotic dehiscence based on the current literature. We will also investigate the role of several biomarkers in predicting the presence of ALs following colorectal surgery. Despite significant improvements in perioperative care, advances in surgical techniques, and a high index of suspicion of this complication, the incidence of AL remained stable during the last decades. Thus, gaining a better knowledge of the risk factors that influence the AL rates may help identify high-risk surgical patients requiring more intensive perioperative surveillance. Furthermore, prompt diagnosis of this severe complication may help improve patient survival. To date, several studies have identified predictive biomarkers of ALs, which are most commonly associated with the inflammatory response to colorectal surgery. Interestingly, early diagnosis and evaluation of the severity of this complication may offer a significant opportunity to guide clinical judgement and decision-making.

Laparoscopic D3 lymph node dissection with left colic artery and first sigmoid artery preservation in rectal cancer

BACKGROUND

D3 lymph node dissection with left colic artery (LCA) preservation in rectal cancer surgery seems to have little effect on reducing postoperative anastomotic leakage. So we first propose D3 lymph node dissection with LCA and first sigmoid artery (SA) preservation. This novel procedure deserves further study.

METHODS

Rectal cancer patients who underwent laparoscopic D3 lymph node dissection with LCA preservation or with LCA and first SA preservation between January 2017 and January 2020 were retrospectively assessed. The patients were categorized into two groups: the preservation of the LCA group and the preservation of the LCA and first SA group. A 1:1 propensity score-matched analysis was performed to decrease confounding.

RESULTS

Propensity score matching yielded 56 patients in each group from the eligible patients. The rate of postoperative anastomotic leakage in the preservation of the LCA and first SA group was significantly lower than that in the LCA preservation group (7.1% vs. 0%, P=0.040). No significant differences were observed in operation time, length of hospital stay, estimated blood loss, length of distal margin, lymph node retrieval, apical lymph node retrieval, and complications. A survival analysis showed patients' 3-year disease-free survival (DFS) rates of group 1 and group 2 were 81.8% and 83.5% (P=0.595), respectively.

CONCLUSION

D3 lymph node dissection with LCA and first SA preservation for rectal cancer may help reduce the incidence of anastomotic leakage without compromising oncological outcomes compare with D3 lymph node dissection with LCA preservation alone.

5 year oncological outcomes of the HIGHLOW randomized clinical trial

INTRODUCTION

The oncological outcomes of low ligation (LL) compared to high ligation (HL) of the inferior mesenteric artery (IMA) during low-anterior rectal resection (LAR) with total mesorectal excision are still debated. The aim of this study is to report the 5 year oncologic outcomes of patients undergoing laparoscopic LAR with either HL vs. LL of the IMA MATERIALS AND METHODS: Between June 2014 and December 2016, patients who underwent elective laparoscopic LAR + TME in 6 Italian non-academic hospitals were randomized to HL or LL of IMA after meeting the inclusion criteria (HighLow trial; ClinicalTrials.gov Identifier NCT02153801). We analyzed the rate of local recurrence, distant metastasis, overall survival, disease-specific survival, and disease-free survival at 5 years of patients previously enrolled.

RESULTS

Five-year follow up data were available for 196 patients. Recurrence happened in 42 (21.4%) of patients. There was no statistically significant difference in the distant recurrence rate (15.8% HL vs. 18.9% LL; P = 0.970) and pelvic recurrence rate (4,9% HL vs 3,2% LL; P = 0.843). No statistically significant difference was found in 5-year OS (p = 0.545), DSS (p = 0.732) or DFS (p = 0.985) between HL and LL. Low vs medium and upper rectum site of tumor, conversion rate, Clavien-Dindo post-operative grade ≥3 complications and tumor stage were found statistically significantly associated to poor oncological outcomes in univariate analysis; in multivariate analysis, however, only conversion rate and stage 3 cancer were found to be independent risk factors for poor DFS at 5 years.

CONCLUSION

We confirmed the results found in the previous 3-year survival analysis, the level of inferior mesenteric artery ligation does not affect OS, DSS and DFS at 5-year follow-up.

High and low inferior mesenteric artery ligation in laparoscopic low anterior rectal resections: A retrospective study

Backgroud

The high or low inferior mesenteric artery (IMA) ligation in rectal cancer remains a great debate. This study retrospectively discussed the outcomes of the perioperative period, defecation and urinary function and long-term prognosis in rectal cancer patients with high or low IMA ligation.

Methods

This study enrolled 220 consecutive rectal cancer cases, including 134 with high IMA ligation and 86 with low ligation. A comparison between the two groups was made for anastomotic leakage, low anterior resection syndrome (LARS), international prostate symptom score (IPSS), 5-year disease-free survival (DFS) and 5-year overall survival (OS).

Results

Low-ligation group had a longer operative time, and larger intraoperative blood loss. No significant difference was noted in anastomotic leakage incidence. In multivariable analysis, the male gender and tumor located at the lower rectum were identified as risk factors for anastomotic leakage. No significant differences were observed between groups in their LARS and IPSS questionnaire responses. The high-ligation vs. the low-ligation 5-year OS and DFS were 78.3% vs. 82.4% and 72.4% vs. 76.6%, respectively, which were not statistically different.

Conclusion

The ligation level of the IMA had no significant effect on the anastomotic leakage incidence, defecation, urinary function, and long-term prognosis.

Comparison of high or modified low tie of the inferior mesenteric artery in laparoscopic rectal cancer surgery: A meta-analysis

OBJECTIVE

The purpose of this study was to perform a meta-analysis comparing the oncological, intraoperative and safety outcomes in laparoscopic rectal cancer surgery with and without preservation of the left colic artery (LCA).

METHOD

We searched several databases including PubMed, Web of Science, Cochrane Library, and Embase databases. This meta-analysis included randomized clinical trials, prospective, and retrospective comparative studies regarding high- or modified low-tie ligation of the inferior mesenteric artery in laparoscopic rectal cancer surgery.

RESULTS

Of 641 potentially eligible articles, 16 studies with 3050 participants met the eligibility criteria and were included in the meta-analysis. There was no significant difference in estimated blood loss (WMD -2.63, 95% CI -5.69 to 0.43; P = .09), the number of harvested lymph nodes (WMD -0.35, 95% CI -1.60 to 0.20; P = .50), the number of apical lymph node yield (WMD -0.19, 95% CI -0.52 to 0.13; P = .24), the number of apical lymph node metastasis (OR 0.76, 95% CI 0.40 to 1.45; P = .40), rate of conversion to open surgery (OR 0.74, 95% CI 0.50 to 1.09; P = .513), rate of urinary dysfunction (OR 1.39, 95% CI 0.71 to 2.74; P = .34), rate of recurrence and metastasis (OR 1.10, 95% CI 0.75 to 1.61; P = .64), 5-year survival rate (OR 0.89, 95% CI 0.67 to 1.18; P = .42). However, this meta-analysis demonstrated a statistically significant difference in operating time (WMD -9.92, 95% CI -15.49 to -5.84; P = .0005), rate of diverting stom (OR 1.42, 95% CI 1.06 to 1.92; P = .02), rate of anastomotic leakage (OR 2.673, 95% CI 1.91 to 3.62; P < .00001), time to first flatus (WMD 0.29, 95% CI 0.11 to 0.48; P = .002), time of hospitalization (WMD 0.64, 95% CI 0.14 to 1.15; P = .01) between the 2 surgical techniques.

COCLUSION

The available evidence suggests that preserving the left colic artery is a safe, effective technique for patients with laparoscopic rectal cancer. nique for patients with laparoscopic rectal cancer.

Does the level of inferior mesenteric artery ligation affect short-term and long-term outcomes of patients with sigmoid colon cancer or rectal cancer? A single-center retrospective study

Background

For sigmoid colon or rectal cancer, a definite consensus regarding the optimal level ligating the inferior mesenteric artery (IMA) has not been reached. We performed this study to determine whether the ligation level significantly affected short-term and long-term outcomes of patients with sigmoid colon or rectal cancer after curative laparoscopic surgery.

Methods

Medical records of patients with sigmoid colon or rectal cancer who had undergone curative laparoscopic surgery between January 2008 and December 2014 at the Department of Gastrointestinal Surgery, Guangdong Provincial Hospital of Traditional Chinese Medicine were reviewed. Then, the high tie group (HTG) was compared with the low tie group (LTG) in terms of short-term and long-term outcomes.

Results

Five-hundred ninety patients were included. No significant differences between two groups regarding baseline characteristics existed. HTG had a significantly higher risk of anastomotic fistula than LTG (21/283 vs 11/307, P = 0.040). Additionally, high ligation was proven by multivariate logistic regression analysis to be an independent factor for anastomotic fistula (P = 0.038, OR = 2.232, 95% CI: 1.047–4.758). Furthermore, LT resulted in better preserved urinary function. However, LTG was not significantly different from HTG regarding operative time (P = 0.075), blood transfusion (P = 1.000), estimated blood loss (P = 0.239), 30-day mortality (P = 1.000), ICU stay (P = 0.674), postoperative hospital stay (days) (P = 0.636), bowel obstruction (P = 0.659), ileus (P = 0.637), surgical site infection (SSI) (P = 0.121), number of retrieved lymph nodes (P = 0.501), and number of metastatic lymph nodes (P = 0.131). Subsequently, it was revealed that level of IMA ligation did not significantly influence overall survival (OS) (P = 0.474) and relapse-free survival (RFS) (P = 0.722). Additionally, it was revealed that ligation level did not significantly affect OS (P = 0.460) and RFS (P = 0.979) of patients with stage 1 cancer, which was also observed among patients with stage 2 or stage 3 cancer. Ultimately, ligation level was not an independent predictive factor for either OS or RFS.

Conclusions

HT resulted in a significantly higher incidence of anastomotic fistula and worse preservation of urinary function. Level of IMA ligation did not significantly affect long-term outcomes of patients with sigmoid colon or rectal cancer after curative laparoscopic surgery.

High Versus Low Ligation of the Inferior Mesenteric Artery in Colorectal Cancer Surgery: A Systematic Review and Meta-Analysis

Background and Objectives: This study aimed to compare the effects of high ligation (HL) versus low ligation (LL) in colorectal cancer surgery. Materials and Methods: We performed a comprehensive search using multiple databases (trial registries and ClinicalTrials.gov), other sources of grey literature, and conference proceedings, with no restrictions on the language or publication status, up until 10 March 2021. We included all parallel-group randomized controlled trials (RCTs) and considered cluster RCTs for inclusion. The risk of bias domains were "low risk," "high risk," or "unclear risk." We performed statistical analyses using a random-effects model and interpreted the results according to the Cochrane Handbook for Systematic Reviews of Interventions. We used the GRADE guidelines to rate the certainty of evidence (CoE) of the randomized controlled trials. Results: We found 12 studies (24 articles) from our search. We were very uncertain about the effects of HL on overall mortality, disease recurrence, cancer-specific mortality, postoperative mortality, and anastomotic leakage (very low CoE). There may be little to no difference between HL and LL in postoperative complications (low CoE). For short-term follow-up (within 6 months), HL may reduce defecatory function (constipation; low CoE). While HL and LL may have similar effects on sexual function in men, HL may reduce female sexual function compared with LL (low CoE). For long-term follow-up (beyond 6 months), HL may reduce defecatory function (constipation; low CoE). There were discrepancies in the effects regarding urinary dysfunction according to which questionnaire was used in the studies. HL may reduce male and female sexual function (low CoE). Conclusions: We are very uncertain about the effects of HL on survival outcomes, and there is no difference in the incidence of postoperative complications between HL and LL. More rigorous RCTs are necessary to evaluate the effect of HL and LL on functional outcomes.

Preservation versus nonpreservation of the left colic artery in anterior resection for rectal cancer: a propensity score-matched analysis

BACKGROUND

Preserving the left colic artery (LCA) during anterior resection for rectal cancer is controversial, and robust evidence of the outcomes of LCA preservation plus apical lymph node dissection is lacking. The purpose of this study was to investigate the impact of LCA preservation plus apical lymph node dissection surgery on anastomotic leakage and number of harvested lymph nodes.

METHODS

Patients who underwent laparoscopic or robotic anterior resection for rectal cancer between September 2017 and May 2020 were retrospectively assessed. The patients were categorized into two groups: preservation of LCA and nonpreservation of LCA. A one-to-one propensity score-matched analysis was performed to decrease confounding. The primary outcome was anastomotic leakage within 30 days after surgery. The secondary outcomes were number of harvested lymph nodes, 3-year overall survival, and 3-year disease-free survival.

RESULTS

A total of 216 patients were eligible for this study, and propensity score matching yielded 60 patients in each group. Anastomotic leakage in the LCA preservation group was significantly lower than that in the LCA nonpreservation group (3.3% vs. 13.3%, P = 0.048). No significant differences were observed in blood loss, operation time, intraoperative complications, splenic flexure mobilization, total number of harvested lymph nodes, number of positive lymph nodes, time to first flatus, or postoperative hospital stay. Kaplan-Meier survival analysis showed a 3-year disease-free survival of 85.7% vs. 80.5% (P = 0.738) and overall survival of 92.4% vs. 93.7% (P = 0.323) for the preservation and nonpreservation groups, respectively.

CONCLUSION

LCA preservation plus apical lymph node dissection surgery for rectal cancer may help reduce the incidence of anastomotic leakage without impairing the number of harvested lymph nodes. Preliminary results suggest that 3-year disease-free survival and overall survival rates may not differ between the two types of surgery, but studies with larger sample sizes are needed to confirm these conclusions. Trial registration ClinicalTrials.gov, NCT03776370. Registered 14 December 2018-Retrospectively registered, https://clinicaltrials.gov .

Systematic review and meta-analysis of randomized controlled trials evaluating the effect of the level of ligation of inferior mesenteric artery on functional outcomes in rectal cancer surgery

BACKGROUND

This systematic review and meta-analysis studied the role of high (HL) versus low (LL) inferior mesenteric artery (IMA) ligation on genitourinary and defecatory dysfunction in patients who had undergone resection for rectal cancer (RC).

METHODS

A systematic literature search of four major databases was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Randomized controlled trials (RCTs) comparing HL and LL of IMA in RC surgery were identified. Those studies that looked at genitourinary or defecatory dysfunction were included. Random-effects modeling to summarize statistics was performed. The risk of bias was assessed using Cochrane's Risk-of-Bias tool 2.

RESULTS

Three RCTs were included. There was clinical heterogeneity with regard to cancer stage and location as well as operative techniques and adjuvant treatments. Functional outcomes (FO) that were reported by at least two studies were International Consultation on Incontinence Questionnaire (ICIQ), International Index for Erectile Function (IIEF), Jorge-Wexner incontinence score (J-W). Difference was observed in ICIQ at 9 months after surgery favoring LL (standard mean difference: - 0.66; 95% confidence intervals (CI): - 0.92, - 0.40; P = 0.37; I 2 = 0%). Difference was also observed in IIEF at 9 months favoring LL (mean difference: 7.43; CI: 1.86, 13.00; P = 0.16; I 2 = 50%).

CONCLUSIONS

Although our study has demonstrated the superiority of LL in genitourinary function preservation, these results should be taken with consciousness due to significant heterogeneity between included studies, small sample size, and potential bias. More high-quality studies are needed.

PROSPERO

CRD4202121099  https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021210998.

Risk Factors and Preventive Measures for Anastomotic Leak in Colorectal Cancer

Anastomotic leak (AL) represents one of the most detrimental complications after colorectal surgery. The patient-related factors and surgery-related factors leading to AL have been identified in previous studies. Through early identification and timely adjustment of risk factors, preventive measures can be taken to reduce potential AL. However, there are still many problems associated with AL. The debate about preventive measures such as preoperative mechanical bowel preparation (MBP), intraoperative drainage, and surgical scope also continues. Recently, the gut microbiota has received more attention due to its important role in various diseases. Although the underlying mechanisms of gut microbiota on AL have not been validated completely, new strategies that manipulate intrinsic mechanisms are expected to prevent and treat AL. Moreover, laboratory examinations for AL prediction and methods for blood perfusion assessment are likely to be promoted in clinical practice. This review outlines possible risk factors for AL and suggests some preventive measures in terms of patient, surgery, and gut microbiota.

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.

Low Ligation Plus High Dissection Versus High Ligation of the Inferior Mesenteric Artery in Sigmoid Colon and Rectal Cancer Surgery: A Meta-Analysis

Background

Whether high or low ligation of the inferior mesenteric artery (IMA) is superior in surgery for rectal and sigmoid colon cancers remains controversial. Although several meta-analyses have been conducted, the level of lymph node clearance was poorly defined. We performed a meta-analysis comparing high and low ligation of the IMA for sigmoid colon and rectal cancers, with emphasis on high dissection of the lymph node at the IMA root in all the included studies.

Methods

PubMed, MEDLINE, and EMBASE databases were searched to identify relevant articles published until 2020. The patient’s perioperative and oncologic outcomes were analyzed. Statistical analysis was performed using the statistical software RevMan version 5.4.

Results

A total of 17 studies, including four randomized controlled trials, published between 2011 and 2020 were selected. In total, 1,846 patients received low ligation of the IMA plus high dissection of lymph nodes (LL+HD), and 2,648 patients received high ligation of the IMA (HL). LL+HD was associated with low incidence of anastomotic leakage (p < 0.001), borderline long operative time (p = 0.06), and less yields of total lymph nodes (p = 0.03) but equivalent IMA root lymph nodes (p = 0.07); moreover, LL+HD exhibited non-inferior long-term oncological outcomes.

Conclusion

In comparison with HL, LL+HD was an effective and safe oncological procedure for sigmoid colon and rectal cancers. Therefore, to ligate the IMA below the level of the left colic artery with D3 high dissection for sigmoid colon and rectal cancers might be suggested once the surgeons are familiar with this technique.

Systematic Review Registration

INPLASY.com, identifier 202190029.