This study innovatively explored simple index of abdominal shape of PAAD, LSA and other parameters on short-term surgical outcomes in patients undergoing LADG. We found that abdominal shape can influence operation time, estimated blood loss, postoperative hospital stay, the number of retrieved lymph nodes and complications. Furthermore, abdominal body shape differed between two genders, males had larger APD and smaller SFT over females. Therefore, we analyzed males and females separately and found that few abdominal shape parameters had an impact on short-term surgical outcomes in females. However, in males, we found some abdominal shape parameters were crucial. The result was consistent with the previously published literature [10–11, 14].
Obesity has always been considered an independent factor in patients with gastric cancer. BMI can be a parameter to represent obesity. Some studies believed that BMI has an impact on postoperative complications and survival [15–16]. In this study, males with BMI < 25 had less operation time and larger number of retrieved lymph nodes. It can be seen that obesity has an impact on the difficulty of LADG in male patients.
The operation time and estimated blood loss can reflect the difficulty of the operation. Previous studies have found that large APD can increase the operation time and Large LRD can increase the amount of surgical bleeding [10–11]. In this study, larger PAAD, SFT, APD and LRD contributed to increase of operation time in males, and smaller XBD contributed to increase of operation time in females. As for estimated blood loss, patients with larger LSA, PAAD, APD, SFT and LRD could experience larger amount of estimated blood loss in males, but all parameters had negative relationship with females. Different distensibility of abdominal wall in men and women due to accumulation of muscle and lipid may explain why abdominal shape was more strongly associated with male patients than female patients . The extra operation time and blood loss may be the large size of abdominal shape and excess fat tissues accumulated around vessels . As for larger LSA resulted in larger amount of estimated blood loss in males, it remained unclear, for LSA is composed of the xiphoid and the rib arch, and it is relatively fixed. We considered, the LSA may increases the space of abdominal cavity, leading to the difficulty and resulting in extra blood loss.
Previous article reported that post-operative complications ranged from 6.1–30% [5, 11, 18–19]. These studies focused on BMI and visceral fat as for post-operative complications [20–21]. In this study, the rate of post-operative complications was 28.2% and patients with higher PAAD and APD had more complications. In univariate analysis, PAAD and APD were independent factors for predicting postoperative complications in males. It may be the large size of abdominal shape which affect the safety of LADG, so, surgeons should be cautious about patients with higher PAAD and APD.
The number of retrieved lymph nodes is related to the effectiveness of the operation. Insufficient number of retrieved lymph nodes may lead to a poor prognosis [22–23]. In this study, lower APD, PAAD and SFT had more retrieved lymph nodes in males, it seems that smaller parameters of abdominal shape can make the surgery of LADG effective. So, much attention should be paid to patients with large parameters of abdominal shape, especially APD, PAAD and SFT.
This study has some limitations as well. First, this is a retrospective study at a single center; Second, this study included patients undergoing LADG, there may be some patients who underwent open gastrostomy because of obesity or converted to open gastrostomy caused by the large amount of bleeding or the difficulty of LADG; Third, this study used CT to estimate the LSA. Ideally, we think the rib arch is a straight line, but actually, the rib arch is a curve and some patients had asymmetrical bilateral costal arches. The calculation of the angle in this study may have some deviation. Fourth, the proportion of women in this study is obviously too small, so the results of women may be biased because of the small amount of data.
In conclusion, various abdominal shapes can influence the difficulty of LADG. Lower LSA and PAAD can reduce the difficulty of LADG in male patients. Therefore, a simple measurement of abdominal shape before surgery can predict the difficulty of surgery.