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

The Atlas of the Inferior Mesenteric Artery and Vein under Maximum-Intensity Projection and Three-Dimensional Reconstruction View

(1) Background: Understanding vascular patterns is crucial for minimizing bleeding and operating time in colorectal surgeries. This study aimed to develop an anatomical atlas of the inferior mesenteric artery (IMA) and vein (IMV). (2) Methods: A total of 521 patients with left-sided colorectal cancer were included. IMA and IMV patterns were identified using maximum-intensity projection (MIP) and three-dimensional (3D) reconstruction techniques. The accuracy of these techniques was assessed by comparing them with surgical videos. We compared the amount of bleeding and operating time for IMA ligation across different IMA types. (3) Results: Most patients (45.7%) were classified as type I IMA, followed by type II (20.7%), type III (22.6%), and type IV (3.5%). Newly identified type V and type VI patterns were found in 6.5% and 1% of patients, respectively. Of the IMVs, 49.9% drained into the superior mesenteric vein (SMV), 38.4% drained into the splenic vein (SPV), 9.4% drained into the SMV-SPV junction, and only 2.3% drained into the first jejunal vein (J1V). Above the root of the left colic artery (LCA), 13.1% of IMVs had no branches, 50.1% had one, 30.1% had two, and 6.7% had three or more branches. Two patients had two main IMV branches, and ten had IMVs at the edge of the mesocolon with small branches. At the IMA root, 37.2% of LCAs overlapped with the IMV, with 34.0% being lateral, 16.9% distal, 8.7% medial, and both the marginal type of IMV and the persistent descending mesocolon (PDM) type represented 1.4%. MIP had an accuracy of 98.43%, and 3D reconstruction had an accuracy of 100%. Blood loss and operating time were significantly higher in the complex group compared to the simple group for IMA ligation (p < 0.001). (4) Conclusions: A comprehensive anatomical atlas of the IMA and IMV was provided. Complex IMA patterns were associated with increased bleeding and operating time.

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.

Revisited Surgical Anatomy of the Left Colonic Angle for Tailored Carcinologic Colectomy: A Review

PURPOSE

Although several types of surgical procedure have been advocated to date, the optimal resection of the left colonic angle in cancer treatment remains controversial. Located at the border of the transverse and descending colons, the anatomy of the left colonic angle is complex and characterized by numerous anatomic variations. Recent advances in preoperative (three-dimensional CT angiography with colonography) and/or intraoperative (indocyanine green staining) imaging have allowed for a better identification of these variations.

METHODS

We performed a methodological review of studies assessing the anatomical variations of the left colic artery.

RESULTS

While the left colonic angle is classically vascularized by branches of the superior and inferior mesenteric arteries, an accessory middle colonic artery has been identified from 6 % to 36% of cases, respectively, leading to their classification of five types. In the absence of a left colic artery, this artery becomes predominant. In parallel to the variations in the venous drainage of the left colonic angle, which has been classified into four types, new lymphatic drainage routes have also been identified via this accessory artery and the inferior mesenteric vein.

CONCLUSIONS

Collectively, these newly obtained findings plead for preoperative identification in cases of cancer of the left colonic angle and a surgical strategy adapted to these anatomical variations.

Selective approach to arterial ligation in radical sigmoid colon cancer surgery with D3 lymph node dissection: A multicenter comparative study

Objectives

Radical surgery for sigmoid colon cancer is commonly performed with complete mesocolic excision (CME) and apical lymph node dissection, reached by central vascular ligation (CVL) of the inferior mesenteric artery (IMA) and associated extended left colon resection. However, IMA branches can be ligated selectively according to tumor location with D3 lymph node dissection (LND), economic segmental colon resection and tumorspecific mesocolon excision (TSME) if IMA is skeletonized. This study aimed to compare left hemicolectomy with CME and CVL and segmental colon resection with selective vascular ligation (SVL) and D3 LND.

Material and Methods

Patients (n= 217) treated with D3 LND for adenocarcinoma of the sigmoid colon between January 2013 and January 2020 were included in the study. The approach to vessel ligation, colon resection and mesocolon excision was based on tumor location in the study group, while in the comparison group, left hemicolectomy with routine CVL was performed. Survival rates were estimated as the primary endpoints of the study. Long- and short-term surgery-related outcomes were evaluated as the secondary endpoints of the study.

Results

The studied approach to the IMA branch ligation was associated with a statistically significant decrease in intraoperative complication rates (2 vs 4, p= 0.024), operative procedure length (225.56 ± 80.356 vs 330.69 ± 175.488, p <0.001), and severe postoperative morbidity (6.2% vs 19.1%, p= 0.017). Meanwhile, the number of examined lymph nodes significantly increased (35.67 vs 26.69 per specimen, p <0.001). There were no statistically significant differences in survival rates.

Conclusion

Selective IMA branch ligation and TSME resulted in better intraoperative and postoperative outcomes with no difference in survival rates.

A clinical study of inferior mesenteric artery typing in laparoscopic radical resections with left colonic artery preservation of rectal cancer

OBJECTIVES

An investigation of the effects of different types of the inferior mesenteric artery (IMA) on laparoscopic left colic artery (LCA) radical resection of rectal cancer was conducted.

METHODS

Clinical data were collected from 92 patients who underwent laparoscopic radical resection of rectal cancer with preservation of the LCA at Nantong University's Second Affiliated Hospital. All patients underwent full-abdominal dual-energy CT enhancement examination before surgery and 3D post-processing reconstruction of the IMA. Two radiologists with >3 years of experience in abdominal radiology jointly conducted the examination. A total of three types of IMA were identified among the patients: IMA type I (the LCA arising independently from the IMA), type II (LCA and sigmoid colon artery [SA] branching from a common trunk from IMA), and type III (LCA, SA, and superior rectal artery [SRA] branching from the IMA at the same point). The baseline data, pathological results, and intra-operative and post-operative indicators of the groups were analyzed.

RESULTS

The proportions of type I, type II, and type III IMA were 58.70% (54/92), 18.48% (17/92), and 22.82% (21/92), respectively. IMA typing was consistent with the preoperative CT evaluation results. The intra-operative blood loss of type III IMA patients [median (interquartile spacing), M (P25, P75): 52.00 (39.50, 68.50) ml] was higher than that of type I and II IMA patients [35.00 (24.00, 42.00) and 32.00 (25.50, 39.50) ml, respectively] (P<0.05). The incidence of anastomotic fistula in type III IMA patients (4 cases, 19.05%) was higher than that in non-type III IMA patients (1 case, 1.41%) (X²=6.679, P=0.010). The incidence of postoperative complications among the three types of IMA was not significantly different (P>0.05).

CONCLUSIONS

Among rectal cancer patients undergoing laparoscopic LCA preservation, type III IMA patients had more intraoperative bleeding and a higher incidence of postoperative anastomotic fistula. However, this did not increase the risk of overall postoperative complications.

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.

A pilot study on preoperative vascular anatomy and clinical application in rectal cancer resection

AIM

To assess the utility of preoperatively evaluating the vascular anatomy using multisection spiral computed tomography angiography (CTA) and image fusion technology in the treatment of obese patients undergoing laparoscopic radical resection for rectal cancer.

MATERIALS AND METHODS

This randomised prospective study included 56 patients who underwent laparoscopic surgery for rectal cancer. Patients were randomly divided into two groups: the fusion imaging group (preoperative CTA and image fusion reconstruction [n=28]) and the control group (not performed CTA and image fusion reconstruction before the operation [n=28]). Duration of surgery was defined as the primary endpoint, and the volume of bleeding, the number of lymph node dissections, conversion to laparotomy, time to recovery of postoperative flatus, length of hospitalisation as well as perioperative complications were defined as secondary endpoints.

RESULTS

Compared with the control group, the duration of surgery in the image fusion group was shorter, bleeding volume was reduced, and the number of lymph node dissections was greater (p<0.05); however, there was no significant differences between the two groups regarding time to postoperative flatus recovery, conversion to laparotomy, length of hospitalisation, and perioperative complications (p>0.05).

CONCLUSIONS

Preoperative assessment of the vascular anatomy was an effective method and avoided some invisible risks during surgery, and resulted in a better therapeutic effect.

Vascular variations encountered during laparoscopic surgery for transverse colon, splenic flexure, and descending colon cancer: a retrospective cohort study

BACKGROUND

Laparoscopic surgery for cancer located in the transverse colon or splenic flexure is difficult because of vascular variability in this region and adjacent vital organs such as the pancreas, spleen, and duodenum.

METHODS

This retrospective cohort study involved 51 patients who underwent laparoscopic surgery for colon cancer at Tokushima University Hospital from July 2015 to December 2020. Variations of the middle colic artery (MCA), left colic artery (LCA), middle colic vein (MCV), and first jejunal vein (FJV) and short-term outcomes of laparoscopic surgery in patients with each vascular variation were evaluated.

RESULTS

Variations of the MCA, LCA, MCV, and FJV were classified into four, three, five, and three patterns, respectively. The short-term outcomes of laparoscopic surgery for transverse colon cancer in patients with MCA variations and those with FJV variations were evaluated, and no significant difference was found in the operation time, blood loss, postoperative complication rate, time from surgery to start of dietary intake, or time from surgery to discharge among the different variations. Additionally, no significant differences were found in the short-term outcomes of laparoscopic surgery for descending colon cancer in patients with LCA variations.

CONCLUSION

Preoperative assessment of vascular variations may contribute to the stability of short-term outcomes of laparoscopic surgery for transverse colon, splenic flexure, and descending colon cancer.

Usefulness of Computed Tomography Angiography in the Preoperative Workup of Patients With Colorectal Cancer

OBJECTIVES

The objective of this study is to analyze the main patterns of branching of the inferior mesenteric artery (IMA) and to determine if your knowledge changes the surgical strategy in the colorectal cancer.

METHODS

This retrospective study included 63 patients with cancer of the sigmoid or rectum. We assessed the patterns of IMA in 3 subtypes: type A (independent left colic artery [LCA]), type B (LCA and sigmoid artery arising in a common trunk) and type C (LCA, sigmoid artery, and superior rectal artery with a common origin). Colorectal surgeons evaluated how the vascular map changed the type of IMA ligation.

RESULTS

Inferior mesenteric artery branching was classified as type A in 55.6% patients, type B in 23.8%, and type C in 20.6%. Knowledge of the vascular map changed the type of ligation from high to low in 20 of the 50 patients who were candidates for surgery. The change was possible in tumors located in the sigmoid colon and the rectosigmoid junction with the type A or B branching.

CONCLUSIONS

Preoperative Multidetector Computed Tomography angiography can define the pattern of IMA branching. Based on this information, a low ligation can be performed in tumors located in sigmoid colon and rectosigmoid junction with IMA branching types A and B.

Surgeon's role in CT-based preoperative determination of inferior mesenteric artery anatomy in colorectal cancer treatment

BACKGROUND

The inferior mesenteric artery (IMA) is a blood vessel of great importance in left colon and rectal cancer surgery. We aimed to determine the role of surgeons in computed tomography (CT) based vascular anatomy interpretation.

METHOD

Patients with left colon and rectal cancer treated surgically with D3 lymph node dissection and selective vascular ligation were included in this study. All patients (n=250) underwent preoperative CT with intravenous contrast. The IMA anatomy was schematically depicted by surgeon based on CT interpretation. Intraoperatively anatomy was defined by skeletonisation of the IMA. All patients had segmental resection with selective vascular ligation. The concurrence of prospectively obtained results were evaluated by intraclass correlation and Kendall's tau-b test. Misinterpretation of IMA anatomy was analysed by CT-specialist.

RESULTS

The preoperative and intraoperative IMA anatomy features were correctly interpreted in 237 cases (in 94.8%) within skeletonisation extent, which is supported by high level of agreement and concordance of preoperative data regards to intraoperative findings (K=0.926; p<0.001; CC=0.912; p<0.001). As a result of the CT-based evaluation of the IMA, E, K, and H types of branching patterns were proposed. IMV position was mistakenly identified in 2.6% of cases.

CONCLUSION

Surgeons are able to evaluate the IMA anatomy accurately with CT and use it in routine preoperative planning. The E, K, and H branching types may be used when defining approach to skeletonisation and level of vascular ligation.

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.

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.

Preservation of the left colic artery and superior rectal artery in laparoscopic surgery can reduce anastomotic leakage in sigmoid colon cancer

Background

The aim was to study the clinical significance in the preservation of the left colic artery (LCA) and superior rectal artery (SRA) for the laparoscopic resection of sigmoid colon cancer (SCC).

Patients and Methods

A total of 316 patients with SCC were divided into two groups. Group A received D3 resection with preservation of LCA and SRA, whereas Group B ligatured artery at the root of the inferior mesenteric artery. The operation time, number of resected lymph nodes, blood loss and anastomotic leakage rate were compared.

Results

In Group A, the average operation time was 283.02 ± 51.48 min, the average blood loss was 111.81 ± 77.08 ml and the average lymph node dissection was 14.8 ± 7.7. There was no statistical significance in blood loss and number of resected lymph nodes between Group A and B (P > 0.05). Longer operating time were observed in Group A as compared to Group B (P < 0.05). The anastomotic leakage rate had statistical significance between these two groups (P < 0.05).

Conclusions

Preservation of LCA and SRA was safe and feasible for the laparoscopic surgery of SCC, which could reduce anastomotic leakage rate.

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.

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.

Vascular anatomy of inferior mesenteric artery in laparoscopic radical resection with the preservation of left colic artery for rectal cancer

AIM

To investigate the vascular anatomy of inferior mesenteric artery (IMA) in laparoscopic radical resection with the preservation of left colic artery (LCA) for rectal cancer.

METHODS

A total of 110 patients with rectal cancer who underwent laparoscopic surgical resection with preservation of the LCA were retrospectively reviewed. A 3D vascular reconstruction was performed before each surgical procedure to assess the branches of the IMA. During surgery, the relationship among the IMA, LCA, sigmoid artery (SA) and superior rectal artery (SRA) was evaluated, and the length from the origin of the IMA to the point of branching into the LCA or common trunk of LCA and SA was measured. The relationship between inferior mesenteric vein (IMV) and LCA was also evaluated.

RESULTS

Three vascular types were identified in this study. In type A, LCA arose independently from IMA (46.4%, n = 51); in type B, LCA and SA branched from a common trunk of the IMA (23.6%, n = 26); and in type C, LCA, SA, and SRA branched at the same location (30.0%, n = 33). The difference in the length from the origin of IMA to LCA was not statistically significant among the three types. LCA was located under the IMV in 61 cases and above the IMV in 49 cases.

CONCLUSION

The vascular anatomy of the IMA and IMV is essential for laparoscopic radical resection with preservation of the LCA for rectal cancer. To recognize different branches of the IMA is necessary for the resection of lymph nodes and dissection of vessels.

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).