A smaller bougie size, shorter distance from the staple line to pylorus and to the angle of His were independently related to increased weight loss, according to researchers from Norway, Sweden and The Netherlands. However, a shorter distance between the proximal staple line and angle of His was also was associated with increased risk of de novo gastro-oesophageal reflux disease (GERD). Therefore, they concluded that surgeons face a delicate balance between achieving superior weight loss and preventing the onset of reflux.
The authors noted that GERD is a potential side-effect of LSG and as the procedure is currently the most commonly performed bariatric procedure worldwide, optimising the surgical technique is of major importance. Nevertheless, there is a paucity of studies that have examined the technical details in relation to weight loss and development of GERD. Therefore, they designed a study that would identify predictors of weight loss within two years after LSG and hypothesised that a more extensive gastric resection would result in greater weight loss and also have an impact on the prevalence of GERD.
Using data from three national registries (Norway (Scandinavian Obesity Surgery Registry , SOReg-N), Sweden (Scandinavian Obesity Surgery Registry, SOReg-S) and the Netherlands (Dutch Audit for Treatment of Obesity, DATO), the researchers noted the surgical technical variables including bougie size measured in Charrière (Ch), the distance from pylorus to the starting point of the gastric resection (cm), and the distance from the angle of His to the gastric resection margin (cm).
Outcomes
In total, 5,927 patients were included in the study. In the univariate analysis of pre-operative characteristics, female sex, higher BMI and smoking were associated with higher total weight loss. Conversely higher age, receiving treatment for depression, T2DM, reflux and sleep apnoea were associated with lower weight loss. For intra-operative variables, a smaller bougie size, a shorter distance to pylorus and the angle of His, and a longer operating time were all associated with higher weight loss. Whereas, the multivariate analysis (data only from Norway and Sweden) showed that female sex, higher BMI, smoking, pre-operative weight loss, smaller bougie size, shorter distance to pylorus, shorter distance to angle of His, and longer hospital stays were all associated with higher weight loss. Higher age, depression, and T2DM were associated with lower weight loss.
The researchers found a linear relationship between the %TWL and the distance to angle of His (only SOReg data available), a smaller bougie size and a shorter distance to pylorus both were associated with a larger %TWL at two years.
A total of 436 patients (7.5%) were treated for GERD pre-operatively while 543 (9.3%) received treatment for GERD two years after the operation. Although 282 of the 436 (65%) obtained GERD remission, 419 out of 5,382 (7.8%) had de novo GERD at two years. Statistically significant predictors of GERD remission were higher age and a shorter distance to pylorus. Importantly, greater weight loss was not associated with GERD remission.
The authors reported that the occurrence of de novo GERD was significantly influenced by a shorter distance to the angle of His, while bougie size was of borderline significance for the development of reflux when %TWL at two years was included as a covariate in the final model (p=0.04-0.05). The smaller the distance to angle of His, the larger the occurrence of de novo GERD.
Overall, there was no relationship between serious complications and any value of the operative variables bougie size, distance to pylorus, and distance to angle of His.
“Stapling close to the angle of His could increase the pressure in the lower esophageal sphincter (LES), but at the same time, dissection and stapling at and around the hiatus might cause breakdown of anatomical structures like the phreno-esophageal membrane which has an important role in keeping the LES intra-abdominally. Hence, resecting close to the angle of His could increase the likelihood of an axial separation between the diaphragmatic crura and the gastro-esophageal junction, allowing intra-thoracic migration of the gastric remnant over time,” the authors noted. “On the other hand, adequate dissection and exposure of the proximal part of the stomach are important to avoid misidentification of the angle of His and a retained fundus. It is considered crucial that the LES remains in an intra-abdominal position and in close proximity to the diaphragmatic crura in order to prevent reflux.”
Therefore, surgeons face a balancing act between performing an adequate exposure and resection of the fundus while at the same time not causing an anatomical aberration that might allow intra-thoracic migration of the gastric remnant.
The researchers added that future research should explore the impact of surgical techniques with low risks, e.g., gastropexy (suturing the divided omentum to the gastric remnant) that may keep the LES intra-abdominally, potentially reducing the risk of reflux.
The findings were reported in the paper, ‘Surgical Aspects of Sleeve Gastrectomy Are Related to Weight Loss and Gastro-esophageal Reflux Symptoms’, published in Obesity Surgery.
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