Is low tie ligation truly reproducible in colorectal cancer surgery? Anatomical study of the inferior mesenteric artery division branches

Short-term outcomes of vessel-oriented D2 and D3 lymph node dissection for sigmoid colon cancer

BACKGROUND

Level of lymph nodes dissection (LND) and inferior mesenteric artery (IMA) ligation is still matter of debate of radical resection of colorectal cancer. This study aims to compare the short-term outcome of three different surgical techniques to treat sigmoid cancer: low ligation (LL) of the IMA with D3-LND, low IMA ligation with D2-LND, and high ligation (HL) of the IMA with D3-LND.

METHODS

Patients affected by sigmoid colon cancer, who underwent radical resection with three different techniques (LL and D3-LND Group A, HL and D3-LND Group B, and LL with D2 LND- Group C), were included. Operative time (min), blood loss (ml), early postoperative complications, and number of harvested lymph nodes were compared.

RESULTS

Thirty patients per group were enrolled. The median operation time was shorter in group C (130 min, interquartile range [IQR] 120-140), compared with the 245 min (IQR 193.8-295.5) of group A and 257 min (IQR 183-345) of group B, p < 0.005. No significant differences between A and B group were observed in the median intraoperative blood loss, while group C had higher intraoperative blood loss (200 ml, IQR 200-260, p = 0.002). Anastomotic leak occurred in three patients belonging to group B. A reduced number of harvested lymph nodes was registered in Group C (14 lymph nodes, IQR 10-17), p < 0.005.

CONCLUSIONS

Both high and low tie ligation with D3-LND for sigmoid cancer can be considered safe and feasible with low rate of postoperative complications, allowing a higher number of harvested lymph nodes compared to low tie ligation with D2 lymphadenectomy.

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.

The value of ICG-guided left colon vascular variation and anatomical rules for the radical resection of proctosigmoid colon cancer

Objective

During laparoscopic radical resection for proctosigmoid colon cancer (PCC), surgeons could inadvertently damage the arteries when following the operation path.This study investigated the variations in left colon blood vessels in order to guide the scientific protection of the marginal artery (MA) during laparoscopic surgery for PCC.

Methods

Data from seven patients who underwent inferior mesenteric artery (IMA) angiography were included as imaging references to preliminarily explore the vascular structure and variation in the left colon. The clinical video data of 183 PCC patients were retrospectively analyzed to observe intraoperative MA injury. Meanwhile, a prospective cohort of 96 patients with the same disease underwent intraoperative indocyanine green (ICG) fluorescence imaging of the peripheral sigmoid artery network, the variation of marginal arteries was summarized, and the distance between vessels and the bowel was measured at different levels. Patients were divided into 'ICG group' and 'non-ICG group' according to whether ICG guidance was performed, and perioperative conditions were compared between the two groups. Taking the integrity of lymph node dissection into consideration, 18 patients underwent carbon nanonode tracing. This study was conducted under the standard consent and ethical approval of the Ethics Committee of our center.

Results

7 patients with IMA angiography shared some vascular structures, defined as 'Dangerous Triangle' and 'Secure Window'. Through intraoperative observation, the primary arch was typically located 4.2 (2.3-6.0) cm away from the intestinal canal, and 5.21% (5/96) patients had poor anastomosis at the primary arch. Moreover, secondary vascular arches (6.4 (4.6-10.0) cm from the intestinal wall) were observed in 38.54% of patients. MA injury was identified in 2 of 183 cases, and the ischemic bowel was timely dissected, whereas no such injury occurred during ICG fluorescenceguided surgery. Guided by carbon nanoparticles, the integrity of lymph node dissection can be maintained while preserving the secondary arch in all patients.

Conclusions

This study demonstrated the benefits of ICG guidance in protecting the intestinal blood supply in laparoscopic PCC surgery. By enhancing the understanding of primary and secondary vascular arches, secure windows, and dangerous triangles, surgeons can safely optimize the surgical path during surgery.

High ligation versus low ligation of the inferior mesenteric artery in laparoscopic rectal cancer surgery: a retrospective study on surgical and long-term outcome

BACKGROUND

In laparoscopic low anterior resection for rectal cancer surgery, there has been controversy to whether the inferior mesenteric artery (IMA) should be ligated at the origin of its aorta (high ligation (HL)) or below the branches of the left colonic artery (LCA) (low ligation (LL)). This study was intended to clarify oncological outcome and long-term prognosis of retrospective analysis.

METHODS

Analyzed the cases who underwent laparoscopic low anterior resection (LAR) in Shanghai Ruijin Hospital from January 2015 to December 2016, 357patients scheduled into 2 groups according to the level of IMA ligation: HL (n = 247) versus LL (n = 110).

RESULTS

The primary endpoint is long-term outcomes, and the secondary endpoint is the incidence rate of major postoperative complications. There were no significant differences in 5-year overall survival (P = 0.92) and 5-year disease-free survival (P = 0.41). There were no differences between the clinical baseline levels in each group. The incidence of low anterior resection syndrome (LARS) in the two groups was statistically significant (P = 0.037). No significant differences were observed in operative time (P = 0.092) and intraoperative blood loss (P = 0.118). In the HL group, 6 cases (2.4%) had additional colonic excision due to poor anastomotic blood supply; none of the colonic anastomosis in the low ligation group had ischemic manifestations, and length from the proximal margin (P = 0.076), length from the distal margin (P = 0.184), the total number of lymph nodes excised (P = 0.065), and anastomotic leakage incidence (P = 0.33).

CONCLUSION

Low ligation of the IMA which reserved LCA with vascular root lymph node dissection in laparoscopic low anterior resection for rectal cancer surgery may help protect the blood supply of the anastomosis, and will not increase postoperative complications while enhance recovery, without compromising radical excision and long-term prognosis.

Discontinuity of marginal artery at splenic flexure and rectosigmoid junction: A systematic review and meta-analysis

AIM

The aim of this study was to provide comprehensive evidence-based assessment of the discontinuity of the marginal artery at the splenic flexure (SF) and the rectosigmoid junction (RSJ).

METHOD

A systematic review was conducted of literature published to 26 December 2022 in the electronic databases PubMed, SCOPUS and Web of Science to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using the Metafor package in R. The primary outcomes were the pooled PPEs of the marginal artery at the SF and the RSJ. The secondary outcome was the size of vascular anastomoses.

RESULTS

A total of 21 studies (n = 2,864 patients) were included. The marginal artery was present at the splenic flexure in 82% (95% CI: 62-95) of patients. Approximately 81% (95% CI: 63-94%) of patients had a large macroscopic anastomosis, while the remainder (19%) had small bridging ramifications forming the vessel. The marginal artery was present at the RSJ in 82% (95% CI: 70-91%) of patients.

CONCLUSION

The marginal artery may be absent at the SF and the RSJ in up to 18% of individuals, which may confer a higher risk of ischaemic colitis. As a result of high interstudy heterogeneity noted in our analysis, further well-powered studies to clarify the prevalence of the marginal artery at the SF and the RSJ, as well as its relationship with other complementary colonic collaterals (intermediate and central mesenteric), are warranted.

Comparison of High Ligation Versus Low Ligation of the Inferior Mesenteric Artery (IMA) on Short-Term and Long-Term Outcomes in Sigmoid Colon and Rectal Cancer Surgery: A Meta-analysis

This study was done to compare the perioperative outcomes and long-term outcomes between low ligation and high ligation of the inferior mesentric artery (IMA) in sigmoid colon and rectal cancer surgery. This study was conducted following the recommendations of the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). A literature search was performed in electronic databases including PubMed, CINAHIL, EMBASE, and Web of Science to identify studies published between January 1, 2015, and April 30, 2023. The outcomes assessed in this meta-analysis included postoperative complications (anastomotic leakage, surgical site infection, and postoperative ileus), intraoperative outcomes (duration of surgery in minutes, total intraoperative blood loss in milliliters, total lymph nodes harvested, and total number of metastatic lymph nodes), recovery outcomes (time to first flatus and length of hospital stay), and long-term outcomes (five-year mortality rate and disease-free survival rate). A total of 17 studies were included in this meta-analysis. Of these, six were randomized control trials (RCTs) and 11 were retrospective cohort studies. This meta-analysis suggests that lower ligation may be associated with a lower risk of anastomotic leakage compared to higher ligation in patients undergoing colon cancer surgery. However, there was no significant difference between the two techniques in terms of surgical site infection, postoperative ileus, total lymph nodes harvested, number of metastatic lymph nodes, duration of surgery, intraoperative blood loss, and length of hospital stay. Time to first flatus was significantly shorter in patients who underwent lower ligation. Additionally, there were no significant differences in the five-year mortality rate and disease-free survival rate between the two techniques. The results of this study indicate that both techniques are comparable in most aspects and suggest that the choice of technique should be based on individual patient factors and surgeon preference.

Comparison of Postoperative Outcome and Prognosis Among Laparoscopic Left Colectomy and Laparoscopic Sigmoidectomy in Sigmoid Colon Cancer Patients: A Propensity Score Matching Study

PURPOSE

The purpose of this study was to investigate the effect of laparoscopic left colectomy (LLC) and laparoscopic sigmoidectomy (LSD) on short-term outcomes and prognosis of sigmoid colon cancer (SCC) patients using propensity score matching (PSM).

METHODS

In this retrospective study, the SCC patients who underwent LLC or LSD surgery were collected from a single clinical center from Jan 2011 to Dec 2019. Short-term outcomes and prognosis were compared between patients who received LSD surgery and LLC surgery.

RESULTS

A total of 356 patients were included in this study. After 1:1 PSM analysis, there were 50 patients who underwent LLC surgery and 50 patients who underwent LSD surgery left in this study. No significant difference was found in baseline characteristics after PSM (P > .05). In comparison with the LLC surgery group, the LSD surgery group had shorter operation time (P = .003) after PSM. Moreover, the surgical procedure was not an independent predictor for overall survival (OS) (P = .918, 95% CI = .333-2.688) and disease-free survival DFS (P = .730, 95% CI = .335-2.150), but age (OS: P = .009, 95% CI = 1.010-1.075; DFS: P = .014, 95% CI = 1.007-1.061) and tumor stage (OS: P = .004, 95% CI = 1.302-3.844; DFS: P < .01, 95% CI = 1.572-4.171) were the independent risk factors for OS and DFS in SCC patients.

CONCLUSION

There was no significant difference between the two surgical procedures for prognosis of SCC patients. However, the possible reasons for changing the surgical procedures should be cautious by surgeons.

The significance of anatomical variation of the inferior mesenteric artery and its branches for laparoscopic radical resection of colorectal cancer: a review

Currently, high or low ligation of the inferior mesenteric artery (IMA) is a controversial issue in laparoscopic radical surgery for colorectal cancer. High or low ligation of the IMA has both advantages and disadvantages, and the level of ligation during the left colon and/or rectum resection has been a dilemma for surgeons. One important factor influencing the surgeon's decision to ligate the IMA in a high or low position is the anatomical type of the IMA and its branches. Some studies confirm that the anatomy of the IMA and its branches is critical to the anastomotic blood supply and, therefore, influences the choice of surgical approach (level of ligation of the IMA). However, many vascular variations in the anatomy of the IMA and its branches exist. Herein, we have summarized the anatomical types of the IMA and its branches, finding that the classification proposed by Yada et al. in 1997 is presently accepted by most scholars. Based on Yada's classification, we further summarized the characteristics of the IMA's various anatomical types as a guide for high or low ligation in radical colorectal cancer surgery.

Mesenteric Vascular Evaluation with Pre-operative Multidetector Computed Tomographic Angiography and Intraoperative Indocyanine Green Angiography to Reduce Anastomotic Leaks after Minimally Invasive Surgery for Colorectal Cancer

Background

The aim of this prospective study was to determine the effect of mesenteric vascular evaluation using pre-operative multidetector computed tomography angiography (MDCTA) and intraoperative indocyanine green (ICG) angiography on reducing the anastomotic leak rate of colorectal cancer patients undergoing minimally invasive resection.

Methods

Twenty-seven consecutive patients with colorectal cancer were studied, 18 males and 9 females, average age 69.1 ± 3.9 years. All patients underwent pre-operative mesenteric vascular evaluation using MDCTA with three-dimensional (3D) reconstruction and intraoperative evaluation of perfusion using ICG angiography. Twelve patients underwent laparoscopic resection (Olympus Visera Elite II OTV-S200) and 15 patients underwent robotic resection (DaVinci Si). Colorectal resection lines and anastomoses were guided by intraoperative ICG perfusion. Postoperative anastomotic leaks were assessed.

Results

Pre-operative MDCTA 3D reconstructions defined the left colic and sigmoid artery anatomy and guided operative planning. The intraoperative ICG angiography resulted in a change of the planned lines of resection in seven patients (26%). The rate of postoperative anastomotic leaks in this study was 0% (0/27), compared to a leak rate of 6.8% at our institution in the preceding two years.

Conclusion

Pre-operative evaluation of mesenteric vascular anatomy using MDCTA with 3D reconstruction and intraoperative evaluation of perfusion using ICG angiography were found to be technically feasible and safe. An appropriately designed study should be undertaken to prove whether it was truly effective at reducing the postoperative anastomotic leak rate in colorectal cancer patients undergoing minimally invasive resection at our institution.

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.

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.

Vascular anatomy of the splenic flexure: a review of the literature

Surgical treatment of the transverse colon is difficult because of the many variations of blood vessels. We reviewed the patterns of vascular anatomy and the definition of the vessels around the splenic flexure. We searched the PubMed database for studies on the vascular anatomy of the splenic flexure that were published from January 1990 to October 2020. After screening of full texts, 33 studies were selected. The middle colic arteries were reported to arise independently without forming a common trunk in 8.9-33.3% of cases. The left colic artery was absent in 0-7.5% of cases. The accessory middle colic artery was present in 6.7-48.9% of cases and was present in > 80% of cases without a left colic artery. The reported frequency of Riolan's arch was 7.5-27.8%. The frequency was found to vary widely across studies, partially due to the ambiguous definition of Riolan's arch. A comprehensive preoperative knowledge of the branching patterns of the middle colic artery and left colic artery and the presence of collateral arteries would be helpful in surgery for colon cancer in the splenic flexure.

High versus low ligation of the inferior mesenteric artery during laparoscopic rectal cancer surgery: A prospective study of surgical and oncological outcomes

BACKGROUND AND OBJECTIVES

There is controversy regarding whether the inferior mesenteric artery (IMA) should be ligated at its origin from the aorta (high ligation, HL) or below the branch of the left colic artery (low ligation, LL) during surgery for rectal cancer.

METHODS

This prospective study randomized 95 patients with histologically proven rectal cancer (clinical stages I-III based on the 8th American Joint Committee on Cancer guidelines) to undergo HL (n = 47) or LL with lymph node dissection at the root of the IMA (n = 48).

RESULTS

Only two intraoperative adverse events were observed (two HL patients experienced anastomotic ischemia and underwent extended bowel excision and splenic flexure mobilization). The LL group had a significantly shorter time to first flatus (p < .0001). No significant differences were observed in operative time (p = .14), intraoperative blood loss (p = .21), distance from the upper margin (p = .77), distance from the lower margin (p = .35), harvested lymph nodes (p = .33), or anastomotic leakage (p = .44), 2-year overall survival (p = .97), or 2-year disease-free survival (p = .42).

CONCLUSION

During laparoscopic low anterior resection, a combination of LL at the IMA and vascular root lymph node dissection may help protect the blood supply of the anastomosis, reduce postoperative complications, and enhance recovery, without compromising radical excision.

Long-term oncological outcomes of low anterior resection for rectal cancer with and without preservation of the left colic artery: a retrospective cohort study

Background

There is uncertainty in the literature about preserving the left colic artery (LCA) during low anterior resection for rectal cancer. We analyzed the effect of preserving the LCA on long-term oncological outcomes.

Methods

We retrospectively collected clinicopathological and follow-up details of patients who underwent low anterior resection for rectal cancer in the General Surgery Department of Guangdong Provincial People’s Hospital, from January 2014 to December 2015. Cases were divided into low ligation (LL), LCA preserved, or high ligation (HL), LCA not preserved, of the inferior mesenteric artery. The 5-year overall survival (OS) and disease-free survival (DFS) rates were compared between the two groups.

Results

Altogether, there were 221 and 295 cases in the LL group and HL groups, respectively. Operating time in the LL group was significantly longer than in the HL group (224.7 vs. 211.7 min, p = 0.039). Postoperative 30-day mortality, early complications including anastomotic leakage showed no significant differences between the LL and HL groups (postoperative 30-day mortality, 0.9% LL, 1.4% HL, p = 0.884; early complications, 41.2% LL, 38.3% HL, p = 0.509; anastomotic leakage 8.6% LL, 13.2% HL, p = 0.100). The median follow-up periods were 51.4 (7–61) months in the LL group and 51.2 (8–61) months in the HL group. During follow-up, the percentages of patients who died, had local recurrence, or had metastases were 39.8, 7.7, and 38.5%, respectively, in the LL group and 39, 8.5, and 40%, respectively, in the HL group; these differences were not significant (all p > 0.05). The 5-year OS and DFS were 69.6 and 59.6% in the LL group, respectively, and 69.1 and 56.2% in the HL group, respectively; these differences were not significant (all p > 0.05). After stratification by tumor-node-metastasis stage, the difference between the 5-year OS and DFS for stages I, II, and III cancer were not significant (all p > 0.05).

Conclusions

The long-term oncological outcomes of LL group are comparable with HL group. LL cannot be supported due to the absence of lower complication rates and the longer operating times.

Surgical anatomy of sigmoid arteries: A systematic review and meta-analysis

BACKGROUND

The purpose of this systematic review and meta-analysis was to determine the prevalence of the number of sigmoid arteries (SA) and variations in their origins.

METHODS

A thorough systematic search of literature through February 2020 was conducted on major electronic databases to identify eligible studies. Data were extracted and pooled into a meta-analysis using Metafor package in R. The primary outcome was the variations in the SA origin (according to modified Zebrowski classification), and the secondary outcome was the prevalence of the number of SA.

RESULTS

A total of 22 studies (n = 2653 patients) were included. Type 1 modified Zebrowski (separated origins or common trunk of the SA originating from descending recto-sigmoid trunk (DRST)) was the most common origin type of the SA (pooled prevalence estimate (PPE) = 49.67% (95% CI 32. 67- 66.71)), while type 3 (separated origins or common trunk of 1 or 2 SA originating from DRST or superior rectal artery (SRA) and 1 or 2 SA originating from DRST or SRA) was the least common (PPE = 0.18%; 95% CI 0.00-2.82)). Of the Type 1 variants, the not specified (N.S) variant was by far the most prevalent. The number of SA ranged from one to five, with three being the mode (PPE = 42.3%).

CONCLUSION

This is the most comprehensive analysis of arterial vascular anatomy of the sigmoid colon. In light of the highly variable anatomical pattern displayed by the SA, thorough pre-operative knowledge of their anatomy can be crucial in minimizing incidences of iatrogenic injury.

Short- and long-term outcomes of rectal cancer patients with high or improved low ligation of the inferior mesenteric artery

The ligation site of the inferior mesenteric artery (IMA) during laparoscopic radical resection for rectal cancer has been controversial. Consecutive patients (n = 205) with rectal cancer who underwent laparoscopic-assisted low anterior resection from January 2009 to December 2015 were retrospectively analyzed. The patients were divided into high ligation (n = 126) and improved low ligation groups (n = 79). A total of 205 rectal cancer patients underwent laparoscopic assisted anterior resection: 126 patients in the high ligation group and 79 patients in the improved low ligation group. The improved low ligation group was better than the high ligation group in terms of postoperative flatus time and postoperative defecation time. There were no differences between the groups in terms of blood loss, operation time, total number of lymph nodes, anastomotic leakage, postoperative time to first liquid diet and postoperative hospital stay. There were also no differences in 5-year overall survival (OS). Compared to high ligation, the improved low ligation ensures the extent of lymph node dissection, and promotes the early recovery of postoperative gastrointestinal function, but does not increase the operation time, bleeding risk, or anastomotic leakage. A ligation site of the IMA in laparoscopic rectal cancer surgery may not influence oncological outcomes.

The sigmoidea ima artery: A player in colonic ischemia?

INTRODUCTION

The sigmoidea ima artery is defined as the lowest sigmoid artery, which forms the distal end of the marginal artery by linking with the superior rectal artery. It supplies the rectosigmoid junction, which is a critical area for ischemia. The aim of the present study was to delineate the area supplied by the inferior mesenteric artery with special consideration of the sigmoidea ima artery.

MATERIALS AND METHODS

The inferior mesenteric artery was dissected from its origin to the bifurcation of the superior rectal artery in 30 cadavers (15 male, 15 female). Vessel length and distance to the promontory were measured for each branch.

RESULTS

There were two manifestations of the sigmoidea ima artery, irrespective of the branching pattern of the inferior mesenteric artery. It originated below the promontory in 25 cases (83.3%) and above it in three (10%). It did not derive from the superior rectal artery in two cases (6.7%). In these 16.7%, the marginal artery was absent near the rectosigmoid junction.

CONCLUSIONS

We suggest the terms "arteria sigmoidea ima pelvina" and "arteria sigmoidea ima abdominalis" for the two variants. The terms "arteria marginalis pelvina" and "arteria marginalis abdominalis" could be applied in clinical practice. An abdominal marginal artery could be considered a risk factor for colonic ischemia in colorectal resections and abdominal aortic aneurysm repair. Both variants should be considered when pre- and intra-operative perfusion measurements are interpreted.

Systematic review and meta-analysis of the anatomical variants of the left colic artery

AIM

To provide a comprehensive evidence-based assessment of the anatomical variations of the left colic artery (LCA).

METHOD

A thorough systematic search of the literature up until 1 April 2019 was conducted on the electronic databases PubMed, SCOPUS and Web of Science (WOS) to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using the Metafor package in R. The primary outcomes of interest were the absence of the LCA and the anatomical variants of its origin. The secondary outcomes were the distance (mean ± SD) between the origin of the inferior mesenteric artery (OIMA) and the origin of the left colic artery (OLCA).

RESULTS

A total of 19 studies (n = 2040 patients) were included. The pooled prevalence estimate (PPE) of LCA absence was 1.2% (95% CI 0.0-3.6%). Across participants with either a Type I or Type II LCA, the PPE of a Type I LCA was 49.0% (95% CI 40.2-57.8%). The PPE of a Type II LCA was therefore 51.0%. The pooled mean distance from the OIMA to the OLCA was 40.41 mm (95 CI% 38.69-42.12 mm). The pooled mean length of a Type I LCA was 39.12 mm (95% CI 36.70-41.53 mm) while the pooled mean length of a Type IIa and Type IIb LCA was 41.43 mm (95% CI 36.90-43.27 mm) and 39.64 mm (95% CI 37.68-41.59 mm), respectively.

CONCLUSION

Although the absence of the LCA is a rare occurrence (PPE 1.2%), it may be associated with an important risk of anastomotic leakage as a result of insufficient vascularization of the proximal colonic conduit. It is also necessary to distinguish variants I and II of Latarjet, the frequency of which is identical, with division of the LCA being technically more straightforward in variant I of Latarjet. Surgeons should be aware that technical difficulties are likely to be more common with variant II of Latarjet, as LCA ligation may be more difficult due to its close proximity to the inferior mesenteric vein (IMV).

Anatomical study of the left colic artery in laparoscopic-assisted colorectal surgery

BACKGROUND

It is important for lymph node dissection around the inferior mesenteric artery (IMA) with preservation of the left colic artery (LCA) to be aware of the track and the length of the LCA. We aimed to investigate the branching pattern and trajectory of LCA and measure the distances from the root of the IMA to the origin of the LCA (D mm) and from the origin of LCA to intersection of LCA and IMV (d mm) during laparoscopic left-sided colorectal operations.

METHODS

We analyzed 106 patients who underwent laparoscope-assisted left-side colorectal surgery during laparoscopic surgery. The branching patterns among the IMA, LCA, and sigmoidal trunk were evaluated; the trajectory of LCA was examined; the D mm and d mm were measured using a length of silk in the surgical operation.

RESULTS

In 59.5% patients, the LCA arose independently from the sigmoidal trunk (type A); in 8.5% patients, the LCA and sigmoidal trunk arose from the IMA at the same point (type B); in 29.2% patients, the LCA and sigmoidal trunk had a common trunk (type C); the LCA did not exist in 2.8% (type D).The D mm and d mm for all cases ranged from 15.0 to 65.3 mm (median, 43.1 mm) and from 20.3 to 46.2 mm (median, 34.8 mm), respectively. 74.8% of the LCA went straight upper left and upward to proximal part of descending colon (type I), 25.2% went to the lower left at first, then turned to travel straight upward to proximal part of descending colon (type II).

CONCLUSION

This study showed the anatomic variations of LCA during laparoscopic left-sided colorectal operation, which would help surgeons safely perform laparoscopic surgery in the left-side colon and rectum.

Lymph node yield, survival benefit, and safety of high and low ligation of the inferior mesenteric artery in colorectal cancer surgery: a systematic review and meta-analysis

PURPOSE

The aim of this meta-analysis was to compare high inferior mesenteric artery (IMA) ligation (HL) with low IMA ligation (LL) for the treatment of colorectal cancer and to evaluate the lymph node yield, survival benefit, and safety of these surgeries.

METHODS

PubMed, Embase, Cochrane Library, Web of Science, and China Biomedical Literature Database (CBM) were systematically searched for relevant articles that compared HL and LL for sigmoid or rectal cancer. We calculated the odds ratio (OR) with 95% confidence intervals (CIs) for dichotomous outcomes and the weighted mean difference (WMD) for continuous outcomes.

RESULTS

In total, 30 studies were included in this analysis. There were significantly higher odds of anastomotic leakage and urethral dysfunction in patients treated with HL compared to those treated with LL (OR = 1.29; 95% CI = 1.08 to 1.55; OR = 2.45; 95% CI = 1.39 to 4.33, respectively). There were no significant differences between the groups in terms of the total number of harvested lymph nodes, the number of harvested lymph nodes around root of the IMA, local recurrence rate, and operation time. Further, no statistically significant group differences in 5-year overall survival rates and 5-year disease-free survival rates were detected among all patients nor among subgroups of stage II patients and stage III patients, respectively.

CONCLUSIONS

LL can achieve equivalent lymph node yield to HL, and both procedures have similar survival benefits. However, LL is associated with a lower incidence of leakage and urethral dysfunction. Thus, LL is recommended for colorectal cancer surgery.

Neurovasculature of high and low tie ligation of the inferior mesenteric artery

Purpose

Controversy exists as to whether a high or low tie ligation of the inferior mesenteric artery (IMA) is the preferred technique in surgeries of the left colon and rectum. This study aims to contribute to the discussion as to which is the more beneficial technique by investigating the neurovasculature at each site.

Methods

Ten embalmed cadaveric donors underwent division of the inferior mesenteric artery at the level of the low tie. The artery was subsequently ligated at the root to render a section of tissue for histological analysis of the proximal (high tie), mid and distal (low tie) segments.

Results

Ganglia observed in the proximal end of seven specimens in the sample imply that there would be disruption to the innervation in a high tie procedure.

Conclusion

This study suggests that a high tie should be avoided if the low tie is oncologically viable.

Randomized clinical trial of high versus low inferior mesenteric artery ligation during anterior resection for rectal cancer

BACKGROUND

The optimal level for inferior mesenteric artery ligation during anterior resection for rectal cancer is controversial. The aim of this randomized trial was to clarify whether the inferior mesenteric artery should be tied at the origin (high tie) or distal to the left colic artery (low tie).

METHODS

Patients were allocated randomly to undergo either high- or low-tie ligation and were stratified by surgical approach (open or laparoscopic). The primary outcome was the incidence of anastomotic leakage. Secondary outcomes were duration of surgery, blood loss and 5-year overall survival.

RESULTS

Some 331 patients entered the trial between June 2006 and September 2012. The trial was stopped prematurely as recruitment was slow. Seven patients were excluded after randomization but before operation because of procedural changes. High tie and low tie were performed in 164 and 160 patients respectively. The incidence of anastomotic leakage was not significantly different (17·7 versus 16·3 per cent respectively; P = 0·731). The incidence of severe complications requiring intervention was 2·4 versus 5·0 per cent for high and low tie respectively (P = 0·222). In multivariable analysis, risk factors for anastomotic leakage included male sex (odds ratio 4·36, 95 per cent c.i. 1·56 to 12·18) and distance of the tumour from the anal verge (odds ratio 0·99, 0·98 to 1·00). At 5 years there were no significant differences in overall (87·2 versus 89·4 per cent respectively; P = 0·386) and disease-free (76·3 versus 77·6 per cent; P = 0·765) survival.

CONCLUSION

The level of ligation of the inferior mesenteric artery does not significantly influence the rate of anastomotic leakage. Registration number: NCT01861678 ( https://clinicaltrials.gov).

High tie versus low tie of the inferior mesenteric artery in colorectal cancer: A meta-analysis

BACKGROUND

Colorectal cancer surgery includes "high tie" and "low tie"of the inferior mesenteric artery(IMA). However, different ligation level is closely related to the blood supply of anastomosis, which may increase the leakage rate, and it is unclear which technique confers a lower anastomotic leakage rate(AL) and survival advantage.

OBJECTIVE

To compare the effectiveness and impact of inferior mesenteric artery (IMA) high ligation versus IMA low ligation on anastomotic leakage, lymph nodes yield rates and 5-year survival.

METHODS

A list of these studies, published in English from 1990 to 2017, was obtained independently by two reviewers from databases such as PubMed, Medline, ScienceDirect and Web of Science. Anastomotic leakage rate, the yield of lymph nodes and 5-year survival were compared using Review Manager 5.3.

RESULTS

There was no significant difference in anastomotic leakage, number of lymph nodes retrieved and 5-year survival rate for both techniques.

CONCLUSIONS

Neither the high tie nor the low tie strategy has an evidence in terms of anastomotic leakage rate, harvested lymph nodes, and the 5-year survival rate. Further RCT is needed.

Adaptive self-organization in the embryo: its importance to adult anatomy and to tissue engineering

The anatomy of healthy humans shows much minor variation, and twin‐studies reveal at least some of this variation cannot be explained genetically. A plausible explanation is that fine‐scale anatomy is not specified directly in a genetic programme, but emerges from self‐organizing behaviours of cells that, for example, place a new capillary where it happens to be needed to prevent local hypoxia. Self‐organizing behaviour can be identified by manipulating growing tissues (e.g. putting them under a spatial constraint) and observing an adaptive change that conserves the character of the normal tissue while altering its precise anatomy. Self‐organization can be practically useful in tissue engineering but it is limited; generally, it is good for producing realistic small‐scale anatomy but large‐scale features will be missing. This is because self‐organizing organoids miss critical symmetry‐breaking influences present in the embryo: simulating these artificially, for example, with local signal sources, makes anatomy realistic even at large scales. A growing understanding of the mechanisms of self‐organization is now allowing synthetic biologists to take their first tentative steps towards constructing artificial multicellular systems that spontaneously organize themselves into patterns, which may soon be extended into three‐dimensional shapes.

Technical difficulties of left colic artery preservation during left colectomy for colon cancer

PURPOSE

Low-tie ligation in colorectal cancer surgery is associated with technical difficulties in left colic artery preservation. We aimed to evaluate and classify the anatomical and technical difficulties of left colic artery (LCA) preservation at its origin and along its route at the inferior border of the pancreas.

METHODS

A vascular reconstruction computed tomography prospective series of 113 patients was analyzed. The inferior mesenteric artery (IMA) branching pattern according to Latarjet's classification (Type I, separate LCA origin, Type II, fan-shaped branching pattern) and the distances between the IMA and the LCA origins and between the LCA and the Inferior mesenteric vein (IMV) at the inferior border of the pancreas were measured.

RESULTS

The IMA branching pattern was Type I in 80 (71 %) patients and Type II in 33 (29 %) patients. The IMA-LCA distance was 39.8 ± 12.2 mm. The LCA-IMV distance at the inferior border of the pancreas was 20.5 ± 21.7 mm. When classified based on this distance, 75 (66 %) patients were classified into the Near subgroup (<20 mm) (7.7 ± 4.1 mm) and 38 (34 %) into the Far subgroup (≥20 mm) (45.6 ± 20.4 mm, p < 0.001). A Type I subgroup F accounted for 27 % of the patients.

CONCLUSIONS

Left colic artery preservation is highly feasible at its origin in more than two-thirds of cases due to the separate origin. The addition of a high IMV ligation increases the risk of damage to the LCA at the inferior border of the pancreas because the distance to the IMV is less than 20 mm in two-thirds of cases.