Anatomical siting of the splenic flexure using computed tomography

Predictors of difficulty in robotic splenic flexure mobilization during rectal cancer surgery

PURPOSE

In surgery for rectal cancer, splenic flexure mobilization is sometimes necessary to ensure a tension-free colorectal anastomosis with adequate blood supply. Splenic flexure mobilization is regarded as a challenging and risky maneuver, but there are no clear indicators of its difficulty in rectal cancer surgery. This study evaluated the impact of clinical and anatomical factors, including splenic flexure height measured qualitatively on the basis of vertebral level using computed tomography, on the difficulty of splenic flexure mobilization during rectal cancer surgery.

METHODS

The enrolled patients underwent robotic splenic flexure mobilization during rectal surgery for primary rectal cancer at Shizuoka Cancer Center in Japan between December 2011 and March 2022. All patients were scheduled to undergo splenic flexure mobilization preoperatively, and all procedures were carried out following a standardized approach. Linear regression analysis was conducted to determine the clinical and anatomical factors significantly influencing the operative time of the abdominal phase, which is defined as the duration from lymph node dissection around the inferior mesenteric artery to the mobilization of the sigmoid and descending colon, including the splenic flexure.

RESULTS

The median operative time for the abdominal phase was 88 min (range, 39-179 min). Univariate analysis revealed that the following variables were significantly correlated with a prolonged abdominal phase: higher body mass index, larger visceral fat area, and higher splenic flexure. In a multiple linear regression analysis, only higher splenic flexure remained significantly associated with a longer abdominal phase (p < 0.01).

CONCLUSIONS

Splenic flexure height measured on the basis of vertebral level using computed tomography may be useful for predicting the difficulty of robotic splenic flexure mobilization in surgery for rectal cancer.

Evaluation of Operative Notes for Splenic Flexure Mobilization: Are the Key Aspects Being Reported?

Background: Given the importance of operative documentation, we reviewed operative notes for surgeries that required splenic flexure mobilization (SFM) to determine their accuracy. Materials and Methods: We performed a retrospective review of 51 operative notes for complete SFMs performed at a single institution from January 2015 to June 2020. Results: None of the operative notes reported a rationale for performing SFM, use of preoperative imaging to guide technical approach, reasoning for the operative method and mobilization approach used, or specific steps taken to ensure that SFM was done safely. Most reports did not include technical details, with one-third of the notes merely reporting that "the splenic flexure was mobilized." Conclusions: Increased awareness about the lack of operative documentation of the critical aspects of the SFM could stimulate initiatives to standardize the SFM method and improve the quality of operative notes for SFM.

Sex differences in the splenic flexure

INTRODUCTION Anecdotally, surgeons claim splenic flexure mobilisation is more difficult in male patients. There have been no scientific studies to confirm or disprove this hypothesis. The implications in colorectal surgery could be profound. The aim of this study was to assess quantitatively whether there is an anatomical difference in the position of the splenic flexure between men and women using computed tomography (CT). METHODS Portal venous phase CT performed for preoperative assessment of colorectal malignancy was analysed using the hospital picture archiving and communication system. The splenic flexure was compared between men and women using two variables: anatomical height corresponding to the adjacent vertebral level (converted to ordinal values between 1 and 17) and distance from the midline. RESULTS In total, 100 CT images were analysed. Sex distribution was even. The mean ages of the male and female patients were 68.1 years and 66.7 years respectively (p=0.630). The mean vertebral level for men was 8.88, equating to the inferior half of the T11 vertebral body (range: 1-17 [superior half of T9 to inferior half of L2]), and 11.36 for women, equating to the inferior half of the T12 vertebral body (range: 4-16 [superior half of T10 to superior half of L2]). This difference was statistically significant (p=0.0001) and is equivalent to one whole vertebra. The mean distance from the midline was 160.8mm (range: 124-203mm) for men and 138.2mm (range: 107-185mm) for women (p<0.0001). CONCLUSIONS The splenic flexure is both higher and further from the midline in men than in women. This provides one theory as to why mobilising the splenic flexure may be more difficult in male patients.