Intraoperative ultrasonic navigation for laparoscopic colorectal surgery with preservation of the left colic artery

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.

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).