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

The left colic artery: a comprehensive analysis

The anatomy of the left colic artery (LCA) is subject to a considerable level of variability, both in its origin, branching pattern, and location in the abdominal cavity. Due to this variability, many studies have tried to describe the vascular anatomy of this anatomical entity using various classifications. It is hoped that the results of the present study may aid surgeons in increasing their anatomical knowledge relevant to colorectal surgeries. A retrospective analysis, including 75 consecutive patients, was conducted to assess the anatomical and morphometric variations of the LCA. Finally, a total of 67 LCAs were included in this study. The majority of the LCA originated directly (N = 48; 71.64%) or indirectly via the colo-sigmoid trunk (N = 18; 26.87%) from the inferior mesenteric artery (IMA). The most common variation of the LCA, according to the Yada, or analogical Wang, classification, was found to be Type I (N = 28; 50.00%). The median diameter of the LCA at its origin was found to be 2.12 mm (LQ = 1.77; HQ = 2.51). The median cross-sectional area of the LCA at its origin was set to be 3.38 mm2 (LQ = 2.29; HQ = 4.33). In conclusion, this study provides a detailed analysis of the anatomical and morphometric variations of the LCA, offering valuable insights for improving the safety and effectiveness of colorectal surgeries, particularly during procedures involving ligation of the IMA. These results emphasize the need for thorough preoperative imaging and anatomical understanding to minimize the risk of iatrogenic injury. Preserving the LCA during low ligation of the IMA is shown to be crucial for maintaining adequate blood supply to the remaining bowel, reducing the risk of ischemia, and ensuring better patient outcomes.

Surgical anatomy of the cystic artery: A systematic review with meta-analysis

BACKGROUND

The current evidence-based systematic review with meta-analysis presents a detailed overview of the cystic artery (CA) surgical anatomy, including its origin, number, topography, and morphometry. Moreover, the surgical implications of these variants are further discussed.

METHODS

According to the Evidence-Based Anatomy Workgroup and PRISMA 2020 guidelines, the systematic review was performed using four online databases. The Anatomical Quality Assurance Tool was used to evaluate the risk of bias. Meta-analysis was performed with the R programming software. The pooled prevalence and pooled mean of different CA parameters were calculated.

RESULTS

The CA most commonly originated from the right hepatic artery (a pooled prevalence of 85.75 %). Other described origins (in order of frequency) were the aberrant right hepatic artery, the common hepatic, the left hepatic, the gastroduodenal, the superior mesenteric, and the middle hepatic arteries. The CA was single in 88.59 %, while it can be identified as double, triple, or absent. Most commonly, it was located inside the cystohepatic triangle in 83.83 %. Most commonly, it was superomedially to the cystic duct (77.80 %) and posteriorly to the common hepatic duct (35.08 %). The CA pooled mean length was 21.34 mm, and its diameter was more commonly over 1 mm.

CONCLUSION

The CA surgical anatomy is paramount when operating on the gallbladder. The CA's altered anatomy and adjacent area could lead to confusion, iatrogenic injury, and prolonged surgical time. The CA depicts high morphological variability; therefore, surgeons should consider the typical anatomy and possible (usual and unusual) variants.

Indocyanine green in left side colorectal surgery segmental resection to decrease anastomotic leak: A parallel retrospective cohort study of 115 patients

BACKGROUND

We investigated the impact of Indocyanine Green (ICG) angiography on reducing anastomotic leakage (AL) after elective left segmental colon resection, including transverse resection. While ICG is widely used in colorectal surgery to assess vascularization, its true effect on AL, particularly in left segmental resections, remains unclear.

STUDY DESIGN

This retrospective, monocentric cohort study included patients undergoing left and transverse colon resection from January 2017 to July 2023. Patients were divided into ICG and no-ICG groups. The primary outcome was AL, with secondary outcomes including postoperative morbidity and length of stay.

RESULTS

Of the 115 patients enrolled, 53 received ICG and 63 did not. AL occurred in 6 patients in the no-ICG group, but none in the ICG group. No significant correlation was found between ICG use and other confounding factors. Postoperative length of stay was also shorter in the ICG group.

CONCLUSIONS

The use of ICG was associated with a reduction in AL, with no cases in the ICG group. These findings suggest a potential benefit of ICG, warranting confirmation in future large-scale studies.

CLINICAL TRIAL REGISTRATION

clinicaltrial.gov (NCT05981937).

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.

Level of Inferior Mesenteric Artery Ligation in Sigmoid Colon and Rectal Cancer Surgery: Analysis of Apical Lymph Node Metastasis and Recurrence

INTRODUCTION

Whether high or low ligation of the inferior mesenteric artery (IMA) is optimal for treating sigmoid colon and rectal cancers is controversial. The present study aimed to compare outcomes of high and low ligation of the IMA and determine the adequate extent of IMA lymph node dissection.

METHODS

Subjects were 455 consecutive stage I-III colorectal cancer patients who underwent curative surgery between 2011 and 2019. We assessed the association between the level of IMA ligation and overall survival and recurrence-free survival (RFS) by propensity score matching analysis. Clinicopathological features of IMA lymph node metastasis and recurrence patterns were analyzed.

RESULTS

After propensity score matching, the low ligation group had a significantly worse prognosis than that of the high ligation group for RFS (p = 0.039). Positive IMA lymph nodes were associated with pathological T3 or T4 stage and N2 stage. IMA lymph node recurrences in the high ligation group occurred at the superior left side of the IMA root. In contrast, all recurrences in the low ligation group occurred at the left colic artery bifurcation.

CONCLUSION

High ligation of IMA is oncologically safe. However, even with high ligation, care must be taken to ensure adequate lymph node dissection.

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.

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.

Left colic artery diameter is an important factor affecting anastomotic blood supply in sigmoid colon cancer or rectal cancer surgery: a pilot study

BACKGROUND

Anastomotic blood supply is vital to anastomotic healing. The aim of this study was to demonstrate the effect of the left colic artery (LCA) on blood supply in the anastomotic area, explore the relationship between individual differences in the LCA and blood supply in the anastomotic area, and elucidate the relevant indications for LCA retention during radical resection for sigmoid or rectal cancer.

METHOD

Radical sigmoid or rectal cancer resection with LCA retention was performed in 40 patients with colorectal cancer who participated in this study. Systemic pressure, LCA diameter, and the distance from the root of the LCA to the root of the inferior mesenteric artery were measured and recorded. The marginal artery stump pressure in the anastomotic colon before and after the LCA clamping was measured, respectively.

RESULTS

There is a significant difference between the marginal artery stump pressure before LCA ligation and after ligation (53.1 ± 12.38 vs 42.76 ± 12.71, p < 0.001). The anastomotic blood supply positively and linearly correlated with body mass index and systemic pressure. Receiver-operating curve analysis revealed that LCA diameter (area under the curve 0.971, cutoff 1.95 mm) was an effective predictor of LCA improving anastomosis blood supply. No relationship was found between the LCA root location and anastomotic blood supply.

CONCLUSION

Preserving the LCA is effective in improving blood supply in the anastomotic area, and larger LCA diameters result in a better blood supply to the anastomotic area.

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.

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.

Anatomy of Subpancreatic Transverse Colon Vessel and Its Clinical Significance: An Observational Study

PURPOSE

To observe and count the probability of presence and the anatomy of the vessel arising via the inferior margin of the pancreas and traveling within the transverse mesocolon, and analyze its clinical significance.

METHODS

Patients who underwent radical operation for transverse colon cancer or descending colon cancer from January 2020 to November 2021 and a nonspecific cadaver were included in this study. We observed and recorded intraoperatively for the probability of presence and the anatomy of the vessel arising via the inferior margin of the pancreas and traveling within the transverse mesocolon. And its property was determined by tissue slice.

RESULTS

A total of 84 patients were included, of which, the vessel was observed in 72 (85.7%) patients, and its property was confirmed by tissue slice of one patient after surgery. The vessel was also observed in a nonspecific cadaver. Originating from transverse pancreatic artery, often one, occasionally two, rarely three vessels arose via the inferior margin of pancreas and supplied the left transverse colon. Artery and vein parallel ran, and it was difficult to separate them due to their small diameter, but the vessels may thicken under certain conditions for increasing blood supply.

CONCLUSION

The vessel, which is not yet reported and named in the literature, can be called the subpancreatic transverse colon vessel, which has a high probability of presence in humans and may be of great significance to human physiological anatomy, surgery, and oncology, and deserves recognition and attention from surgeons.

The Dilemma of the Level of the Inferior Mesenteric Artery Ligation in the Treatment of Diverticular Disease: A Systematic Review of the Literature

Background and aim: Although sigmoidectomy is a well-standardized procedure for diverticular disease, there are still unclear areas related to the varying morphology and vascular supply of the sigmoid colon. The level of vascular ligation could affect the functional outcomes of patients operated on for diverticular disease. The aim of this review is to primarily evaluate sexual, urinary and defecatory function outcomes, as well as postoperative results, in patients who underwent surgery for diverticular disease, with or without inferior mesenteric artery (IMA) preservation. Materials and methods: The MEDLINE/PubMed, WOS and Scopus databases were interrogated. Comparative studies including patients who underwent sigmoidectomy for diverticular diseases were considered. Bowel function, genitourinary function, anastomotic leak, operation time, conversion to open surgery, anastomotic bleeding, bowel obstruction were the main items of interest. Results: Twelve studies were included in the review, three randomized and nine comparative studies. Bowel and genitourinary function are not differently affected by the level of vascular ligation. The site of ligation of IMA did not influence the rate of functional complications, anastomotic leak and bleeding. Of note, the preservation of IMA is associated with a higher conversion rate and longer operative time. Conclusions: Despite the heterogeneity of patient groups, and although the findings should be interpreted with caution, functional and clinical outcomes after sigmoidectomy for diverticular disease do not seem to be affected by the level of vascular ligation as long as the IMA is ligated far from its origin.

Level of inferior mesenteric artery ligation does not affect rectal cancer treatment outcomes despite better cancer-specific survival after low ligation-randomized trial results

AIM

In rectal cancer surgery, the problem about which of the mesenteric artery ligation variants (high or low) is more beneficial to the patient remains unsolved. Recent meta-analyses suggest that the risk of surgical complications is similar for both ligation variants. The main objective was to compare the survival time in both groups with a minimum 48 months' follow-up. Secondary objectives were comparison of the number of harvested lymph nodes, the complication rate and other selected data related to the surgery.

METHOD

This was a randomized, single-centre, unblinded clinical trial of adult patients (n = 130) with cT1-3M0/ycT0-3M0 rectal and rectosigmoid junction adenocarcinoma undergoing radical open surgery. The intervention level was inferior mesenteric artery ligation.

RESULTS

The mean and median survival in the whole group was 45 months, while in the survivor group it was 83 and 82 months. The survival for 1-5 years, overall survival and disease-free survival were similar in both groups. The cancer-specific survival time was longer in the low inferior mesenteric artery ligation group (P = 0.005 for all and P = 0.02 for pTNM Stage III patients) There were no differences in the incidence of anastomotic leakage and overall morbidity. The median number of lymph nodes located at the root of the inferior mesenteric artery was 1; the mean was 1.7. They were not metastatic in any case. The median total number of harvested nodes was similar in both groups.

CONCLUSIONS

In radically treated adenocarcinoma of the rectum and the rectosigmoid junction, the level of inferior mesenteric artery ligation below the left colic artery branch provides similar treatment results to inferior mesenteric artery ligation just below its branching from the aorta in relation to overall and disease-free survival, and the risk of complications. Low inferior mesenteric artery ligation results in better cancer-specific survival. The risk of metastases at the mesenteric nodes is negligible.

Anatomical study of the inferior mesenteric vein using three-dimensional computed tomography angiography in laparoscopy-assisted surgery for left-sided colorectal cancer

PURPOSE

To investigate the drainage patterns of the inferior mesenteric vein (IMV) and measure the distance from the root of the inferior mesenteric artery (IMA) to the IMV using preoperative three-dimensional computed tomography (3D-CT) angiography in patients undergoing surgery for left-sided colorectal cancer.

METHODS

In this retrospective study, we analyzed data collected prospectively on 167 consecutive patients who underwent laparoscopic left-sided colorectal cancer surgery between July, 2014 and August, 2019. The drainage pattern of the IMV and the distance from the root of the IMA to the IMV were evaluated using 3D-CT angiography. We also assessed intraoperative adverse events and postoperative outcomes.

RESULTS

The IMV drained into the superior mesenteric vein (SMV) in 44 patients, into the confluence point of the SMV and splenic vein (SV) in 38 patients, into the SV in 83 patients, and into the middle colic vein in the remaining three patients. The median length from the root of the IMA to the IMV was 22.1 mm (1.3-84.9). IMV injury occurred in only one patient during surgery, but resulted in colonic ischemia.

CONCLUSION

3D-CT angiography is useful for the preoperative assessment of vascular anatomical variations of the IMV and IMA for safe intraoperative navigation and prevention of complications during laparoscopy-assisted left-sided colorectal surgery.

Definition and characterization of the descending branch of the left colic artery

PURPOSE

The descending branch of the left colic artery (dLCA) is under-recognized and has not been clearly defined. The dLCA is often confused with the sigmoid artery (SA) originating from the left colic artery (LCA). We clarified the anatomical characteristics of the dLCA and searched for surrogate measures to identify it.

METHODS

Arterial phase, venous phase, and three-dimensional images of abdominal arteries were created in 411 patients using contrast-enhanced computed tomography (CT). We analyzed the branching patterns of the inferior mesenteric artery (IMA) based on CT. The dLCA was defined as the artery originating from the LCA that flows into the marginal artery along the descending colon. We tested three candidate diagnostic measures for the dLCA using positional relationships and the segment length of vessels.

RESULTS

Arteries from the LCA were present in 360 patients, among which 459 dLCAs and 165 SAs were identified in 333 and 146, respectively. By the first measure of identifying the artery with its root lateral to the inferior mesenteric vein (IMV) as the dLCA, the sensitivity, specificity, and accuracy rate were 94%, 87%, and 92%, respectively. The second measure of identifying the artery with its root higher than the root of the IMA as the dLCA and the third of identifying the artery with its root located > 27.6 mm from the root of LCA as the dLCA yielded lower accuracy rates (69% and 89%, respectively).

CONCLUSION

Our study demonstrated that dLCAs are prevalent (93%) and may be easily found lateral to the IMV in clinical practice.

The New Concept of Physiological "Riolan's Arch" and the Reconstruction Mechanism of Pathological Riolan's Arch After High Ligation of the Inferior Mesenteric Artery by CT Angiography-Based Small Vessel Imaging

Background

Due to the complexity of anatomical relationship between superior mesenteric artery (SMA) and left colic artery (LCA), there is no unified anatomical concept of "Riolan's arch." There is no consensus as to tie off the inferior mesenteric artery (IMA) at its origin or just below the origin of the left colic artery during radical surgery of sigmoid colon and rectal cancers. The aim of the study is to investigate the anatomy of shortcut anastomotic branches (adjacent branches) of SMA at splenic flexure and to explore how the shortcut pathway (Riolan's arch) was formed, as the compensation of anastomotic branches between MCA and LCA under pathological conditions and the reconstruction and the mechanism of pathological Riolan's arch after high ligation of the inferior mesenteric artery.

Methods

Between January 2018 and May 2020, patients with colorectal cancer who underwent CTA before surgery were enrolled in the study. The anatomy of shortcut anastomotic branch of SMA and LCA was investigated by volume rendering technique (VR) and maximum-intensity projection (MIP). GE's small vessel extraction technology (selected VR) was used to directly display these shortcut anastomotic branches on a map and to establish their three-dimensional anatomical classification. Then, we used the axonometric drawing to make the model more exact. Next, combining with some cases of pathological Riolan's arch and basing on hydrodynamic principle, we speculate the mechanism of collateral circulation. Finally, based on the retrospective study of high ligation cases and combined principles of fluid mechanics, we show how these shortcut anastomotic branches evolved into Riolan's arch.

Results

We report the classification of the ascending branch of LCA (which approaches the splenic flexure) and the left branch of MCA, display these shortcut anastomotic branches on a map, and establish their three-dimensional anatomical classification. We found that Riolan's arch is a shortcut pathway for the compensation of anastomotic branches, between MCA and LCA under pathological conditions, and that the formation mechanism of shortcut path accords with the principle of hydrodynamics.

Conclusions

Our results show the mechanism of pathological Riolan's arch formation and provide new anatomic thinking for the battle between high and low ligation of IMA in colorectal cancer surgery.

Pathological features of lymph nodes around inferior mesenteric artery in rectal cancer: a retrospective study

Objective

This study aimed to explore the pathological characteristics of lymph nodes around inferior mesenteric artery in rectal cancer and its risk factors and its impact on tumor staging.

Methods

485 rectal cancer patients underwent proctectomy surgery were collected in this study. Clinical features of patients, including gender, age, BMI, tumor size, pathological type, differentiation, nerve invasion, lymph nodes, tumor marker, and pathological examinations, were analyzed.

Results

A total of 485 cases were included in this study. There were 29 cases with IMA-LN metastasis; the metastasis rate was 5.98% (29/485). Positive IMA-LNs were associated with distance from anal verge, CEA, pathological type, differentiation, nerve invasion, T stage, and N stage. Multivariate analysis showed that distance from anal verge, CEA level, differentiation, and T stage were independent risk factors for positive IMA-LNs.

Conclusion

Distance from anal verge, CEA level, differentiation, and T stage were independent risk factors for positive IMA-LNs. No skip metastasis occurred in IMA-LNs. We should choose the appropriate surgical methods to achieve better oncological results and reduce the incidence of postoperative complications.

Variant Arterial Supply of the Descending Colon by the Coeliac Trunk: A Case Report

Background and Objectives: Knowledge of arterial variations of the intestines is of great importance in visceral surgery and interventional radiology. Materials and Methods: An unusual variation in the blood supply of the descending colon was observed in a Caucasian female body donor. Results: In this case, the left colic artery that regularly derives from the inferior mesenteric artery supplying the descending colon was instead a branch of the common hepatic artery. Conclusions: Here, we describe the very rare case of an aberrant left colic artery arising from the common hepatic artery in a dissection study.

Discrepancy between surgeon and radiological assessment of ligation level of the inferior mesenteric artery in patients operated for rectal cancer-impacting registry-based research and surgical practice

Background

The reliability of the registered ligation level of the inferior mesenteric artery (IMA) in the Swedish Colorectal Cancer Registry has been questioned. The primary aim of this study was to evaluate this parameter in the registry by comparing the registered ligation levels with a postoperative computed tomography angiography (CT-angiography) in patients operated for rectal cancer.

Methods

Patients operated for rectal cancer at two Swedish university hospitals were prospectively included between December 2016 and December 2019. At the 1-year postoperative follow-up, an additional CT-angiography was performed and independently examined by two radiologists. The radiological assessment of the ligation level was compared to registry data, using different measures of agreement.

Results

A total of 94 patients were included, 55 (59%) were men and 39 (41%) women. All patients underwent abdominal resection: conventional or robot-assisted laparoscopic surgery, n=56 (60%), or open resection, n=38 (40%). The ligation level as assessed on CT-angiography was high in 29 (31%) patients and low in 65 (69%). The registered level of ligation of the IMA and the radiological assessment of the CT-angiographies were consistent in 77/94 cases, demonstrating an 82% agreement and a sensitivity and specificity of 86% and 72%, respectively. The estimated Kappa value was 0.58, reaching 0.64 after prevalence bias adjustment.

Conclusion

This study showed that CT-angiography can be used to evaluate the reliability of the registered ligation level in the Swedish Colorectal Cancer Registry. The demonstrated agreement between the registry and postoperative CT-angiography was moderate to good. This discrepancy impacts registry-based research using IMA ligation data and may ultimately influence surgical practice.

Trial registration

Clinical Trials identifier NCT03875612

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02222-5.

Metastasis to lateral lymph nodes with no mesenteric lymph node involvement in low rectal cancer: a retrospective case series

PURPOSE

The aim of this study is to examine the pattern of lymph node metastasis (lateral vs. mesenteric lymph nodes) in low rectal cancer.

METHODS

This retrospective analysis included all patients undergoing laparoscopic total mesorectal excision plus lateral lymph node dissection for advanced low rectal cancer (up to 8 cm from the anal verge) during a period from July 1, 2017, to August 31, 2019, at the Department of Colorectal Surgery, Tianjin Union Medical Center. The decision to conduct lateral lymph node dissection was based on positive findings in preoperative imaging assessments.

RESULTS

A total of 42 patients were included in data analysis. Surgery was successfully completed as planned, without conversion to open surgery in any case. A minimum of 10 mesenteric lymph nodes and 1 lateral lymph node on each side were dissected in all patients. Pathologic examination of resected specimens showed no metastasis to either mesenteric or lateral lymph nodes in 7 (16.7%) case, metastasis to both mesenteric and lateral lymph nodes in 26 (61.9%) cases, metastasis to mesenteric but not lateral lymph nodes in 4 (9.5%) cases, and metastasis to lateral but not mesenteric lymph nodes in 5 (11.9%) cases (n = 2 in the obturator region; n = 3 in the iliac artery region).

CONCLUSION

A clinically significant proportion of low rectal cancer patients have metastasis to lateral lymph nodes without involvement of mesenteric lymph nodes. More carefully planned prospective studies are needed to verify this preliminary finding.

The feasibility of laparoscopic TSME preserving the left colic artery and superior rectal artery for upper rectal cancer

BACKGROUND

Laparoscopic tumor-specific mesorectal excision (TSME) preserving the left colic artery and superior rectal artery is still a technically challenging procedure. We conducted this study to demonstrate the feasibility of this procedure for upper rectal cancer.

METHODS

A total of 184 patients with upper rectal cancer were retrospectively analyzed in our cancer center between April 2010 and April 2017. These patients were treated with either laparoscopic TSME (n = 46) or laparoscopic total mesorectal excision (TME) (n = 138). In the TSME group, the left colonic artery and superior rectal artery were preserved while they were not in the TME group.

RESULTS

The operation time in the TSME group was longer than that in the TME group (218.56 ± 35.85 min vs. 201.13 ± 42.65 min, P = 0.004). Furthermore, the number of resected lymph nodes in the TSME group was greater than that in the TME group (19.43 ± 9.46 vs. 18.03 ± 7.43, P = 0.024). The blood loss between the TSME and TME groups was not significant. No mortality occurred in either the TSME or TME groups. One patient in the TME group underwent conversion to laparotomy. The total postoperative complication rates in the TSME and TME groups were 8.7% and 17.4%, respectively. There was no difference in severe complications between the two groups (anastomotic leakage and stenosis).

CONCLUSIONS

Laparoscopic TSME preserving the left colic artery and superior rectal artery can be safely conducted for upper rectal cancer.