|Year : 2020 | Volume
| Issue : 1 | Page : 39-43
Volume of resected stomach after laparoscopic sleeve gastrectomy and its correlation with initial body mass index and weight loss
Kshitij Kirane1, Deepak Phalgune2, Shashank Shah3
1 Department of Surgery, Poona Hospital and Research Centre, Pune, Maharashtra, India
2 Department of Research, Poona Hospital and Research Centre, Pune, Maharashtra, India
3 Department of Laparoscopic Surgery, Poona Hospital and Research Centre, Pune, Maharashtra, India
|Date of Submission||27-Jun-2020|
|Date of Acceptance||10-Dec-2020|
|Date of Web Publication||19-Jan-2021|
Dr. Deepak Phalgune
18/27, Bharatkunj - 1, Erandawane, Pune - 411 038, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: The relation between the resected stomach volume (RSV) and the weight loss after laparoscopic sleeve gastrectomy (LSG) appears conflicting in the literature. The aim of the present research was to find the correlation of RSV after LSG, the percentage of excess weight loss (%EWL) at 6-month and 1-year follow-up, and the initial body mass index (BMI).
Materials and Methods: Sixty patients aged between 18 and 60 years who underwent LSG were included. Preoperatively, the baseline data of patients such as BMI and presence of Type 2 diabetes mellitus were noted. LSG was performed under general anesthesia. The resected stomach was punctured with Veress needle and insufflated with CO2. The maximum volume was recorded as RSV. The sleeve volume was measured by the amount of methylene blue used to distend the stomach during the leak test. %EWL was calculated at 6 months and 12 months. The primary outcome measures were to find the correlation of RSV with %EWL and BMI, whereas the secondary outcome measure was to find the correlation of vertical length of staple line with %EWL. Comparison of categorical and continuous variables was done using Chi-square test/Fisher's exact test and unpaired t-test, respectively. Correlation analysis was done using Pearson's correlation technique.
Results: The RSV positively correlated with initial BMI (r = 0.456). There was no significant correlation of RSV, sleeve volume, and vertical length of staple line with %EWL at 6-month and 12-month postoperative intervals.
Conclusion: RSV positively correlated with baseline BMI, but not correlated with %EWL.
Keywords: Body mass index, laparoscopic sleeve gastrectomy, percentage of excess weight loss, resected volume of stomach
|How to cite this article:|
Kirane K, Phalgune D, Shah S. Volume of resected stomach after laparoscopic sleeve gastrectomy and its correlation with initial body mass index and weight loss. Saudi Surg J 2020;8:39-43
|How to cite this URL:|
Kirane K, Phalgune D, Shah S. Volume of resected stomach after laparoscopic sleeve gastrectomy and its correlation with initial body mass index and weight loss. Saudi Surg J [serial online] 2020 [cited 2021 Feb 28];8:39-43. Available from: https://www.saudisurgj.org/text.asp?2020/8/1/39/307416
| Introduction|| |
Obesity is one of the important factors associated with many comorbid conditions. Obesity is also a social stigma which influences the well-being of the affected individual negatively. For the management of obesity, many options are currently available.,, The surgical management is considered the most effective and long-term solution to the condition. Sleeve gastrectomy is one of the surgical techniques available. Recently, some surgeons have begun to perform laparoscopic sleeve gastrectomy (LSG) as a sole procedure for morbidly obese patients., Many factors contribute to weight loss after LSG, of which the major factor in the success of the procedure is said to be volume restriction. Ghrelin, an appetite-stimulating hormone released mainly from the fundic glands, is reported to get decreased postoperatively. This also plays an important role in weight loss. Rapid gastric emptying, and faster intestinal transit after LSG, is said to be contributing to weight loss. This is also associated with the metabolic effects responsible for the improvement of Type 2 diabetes mellitus (T2DM).,,
The relation between the resected stomach volume (RSV) and the weight loss after LSG appears conflicting in the literature. Both the residual and the resected volumes represent the total gastric volume, and if the weight loss is related to one of the two volumes, it should be related to the other. While some reports indicate that the weight loss is related to RSV, others state that the weight loss is related to the residual volume of the stomach. The aim of the present research was to find the correlation between RSV after LSG, the percentage of excess weight loss (%EWL) at 6-months and 1-year follow-up, and the initial body mass index (BMI).
| Materials and Methods|| |
All the patients of both sexes between the age of 18 and 60 years admitted from July 2017 to October 2018 for LSG, and ready to participate, were included after explaining the potential advantages and risks. Written informed consent was taken from all the patients. Permission was obtained from the ethics committee (letter no. RECH/EC/2017-18/370) of the institution for this prospective observational study. Patients were excluded from the study if the resected stomach was torn or patients were lost to follow-up. Based on a previous study, setting an alpha error at 0.05 and power at 80%, the sample size of 55 patients was calculated by a formula. To validate the results, we included 65 patients.
Each patient underwent preoperative evaluation by a bariatric surgeon, an anesthesiologist, a physician, and a nutritionist. Patients were prescribed a very low-calorie diet prior to surgery. Standard prophylaxis against deep-venous thrombosis included administration of low-molecular-weight heparin from 12 h before surgery. Preoperative baseline data of patients such as age, sex, height, preoperative weight, BMI, and presence of T2DM were noted. LSG was performed under general anesthesia with endotracheal intubation. Standard position was given with the application of a sequential compression device on both legs. LSG was performed using two 10-mm ports and two 5-mm ports. The procedure was performed with standard steps without any major changes. The bougie size used was 34 Fr, which was consistent for all the procedures in all the cases. The sleeve creation was started with the first firing at 5 cm from the pylorus. Reinforcement of the staple line was done. A leak test with methylene blue was used to demonstrate the integrity of the staple line. Before performing a methylene blue test, the pylorus was clamped. When the tip of the tube was at the hiatus, we injected methylene blue under high pressure till the stomach was fully tense and the dye started refluxing into the esophagus. There would be marginal error in the final pressure and reflux as monitoring both simultaneously is difficult. However, that difference in distensibility would not be very significant. A drain was placed in the left subdiaphragmatic space. The resected stomach was then retrieved from the 10-mm port site [Figure 1]. The same technique was used in all the patients.
Method of measurement of sleeve volume and volume of the resected stomach
The resected stomach was punctured with Veress needle and insufflated with CO2 at a pressure of 20 mmHg using an endoflator in all patients, and the maximum volume was recorded. As the pressure in the resected stomach increased, and reached 20 mmHg, the flow via the endoflator stopped to give us the volume of the resected stomach. The volume of stomach in the patient's body (sleeve) was measured by the amount of methylene blue used to distend the stomach during the leak test performed after clamping the pylorus. The only way to measure the volume of sleeve was by methylene blue instillation as gas insufflation was not possible. We have a dedicated biomedical team in our hospital. The gas insufflator was calibrated by them every time.
Method of calculation
- Volume of sleeve = Amount of methylene blue used for the leak test
- Volume of the resected stomach = Amount of CO2 required to insufflate the stomach to maximum at standard pressure (20 mmHg)
- Vertical length of the stomach from 5 cm proximal to the pylorus to the angle of His.
The staple length was measured as the total length of the staples used. Sometimes, it could be tortuous, and be marginally more than the actual vertical length of the sleeve. The intention was to measure the entire suture line length from the apex to the lower part. The straight vertical length would be marginally less than the actual staple line. The vertical length of staple line was measured by addition of the length of staplers used during LSG while considering the length which was actually used for the last stapler.
Postoperatively, the patients were ambulated immediately and were started on a clear liquid diet on the 2nd day and discharged on the 3rd postoperative day. They were called back after a week for follow-up and again at 1-, 6-, and 12-month postoperative intervals.
- Approximate total volume of stomach = volume of sleeve + volume of the resected stomach
- Broca's index was used to calculate the ideal body weight (IBW) using the formula IBW = Height (cm) − 100
- %EWL = ([Weight lost]/[preoperative weight − ideal weight]) × 100%. EWL was calculated at 6-month and 12-month intervals using the above formula.
The primary outcome measures were to find the correlation of RSV with %EWL and BMI, whereas the secondary outcome measure was correlation of vertical length of staple line with %EWL.
Data collected were entered in Excel 2007, and analysis of data was done using Statistical Package for Social Sciences for Windows, version 20.0 from IBM Corporation Armonk, NY, USA. Data on categorical variables were shown as n (% of cases), and the data on continuous variables were presented as mean and standard deviation (SD). The intergroup comparison of categorical variables was done using Chi-square test or Fisher's exact test. The statistical significance of intergroup difference of means of continuous variables was done using unpaired t-test. The underlying normality assumption was tested before the statistical analysis. Correlation analysis was done using Pearson's correlation technique by adjusting the linear effect of the confounders such as age and sex. In the entire study, P < 0.05 was considered statistically significant.
| Results|| |
Initially, 65 patients were included in the study, but 5 patients were excluded as 4 were lost to follow-up and the resected stomach of one patient got torn. Hence, the analysis was done using the data of the sixty patients. Of the 60 cases studied, 22 (36.7%) were male and 38 (63.3%) were female. The mean ± SD of the age of the cases studied was 43.7 ± 12.6 years. The mean preoperative body weight was 109.0 ± 16.9 kg. The mean preoperative BMI was 42.6 ± 6.3 kg/m2. Twenty-seven (45.0%) patients had T2DM. Of the 60 cases studied, 8 (13.3%), 21 (35.0%), 8 (13.3%), 16 (26.7%), and 7 (11.7%) had initial BMI between 31.00 <35 kg/m2, 35.00 <40 kg/m2, 40.00 <45 kg/m2, 45.00 <50 kg/m2, and ≥50.00 kg/m2, respectively.
The mean RSV of the entire study population was 973.3 ± 105.6 mL. The distribution of mean RSV and mean total volume of stomach was significantly higher in males as compared to females [Table 1]. The mean %EWL of the entire study population at 6- and 12-month interval after surgery was found to be 47.9 ± 14.1 kg and 60.5 ± 16.7 kg, respectively. The mean %EWL for males at 6- and 12-month interval was 51.9 ± 12.7 kg and 66.4 ± 16.9 kg, respectively. The mean %EWL for females was 45.6 ± 14.5 at 6-month interval and 57.1 ± 15.8 at 12-month interval.
|Table 1: Comparison of mean resected and total volume of stomach according to gender|
Click here to view
The RSV showed a statistically significant positive (r = 0.422) correlation with BMI at baseline (P = 0.001) in the entire group of cases studied. The RSV did not show statistically significant correlation with %EWL loss at 6-month (r = −0.220 and P = 0.091) and at 12-month (r = −0.148 and P = 0.258) postsurgery follow-up intervals. The sleeve (remaining volume of stomach) volume in our study was found to be between 80 and 125 mL. The sleeve volume did not show statistically significant correlation with %EWL at 6-month (r = −0.010 and P = 0.938) and at 12-month (r = −0.076 and P = 0.566) postoperative follow-up intervals. The mean vertical length of staple line was found to be 27.40 cm. The vertical length of staple line did not show statistically significant correlation with %EWL at 6-month (r = −0.097 and P = 0.460) and 12-month (r = −0.066 and P = 0.615) postoperative follow-up intervals.
| Discussion|| |
In the present study, the RSV did not show statistically significant correlation with %EWL at 6-month and 12-month postoperative follow-up intervals. The RSV showed a statistically significant positive correlation with BMI at baseline. In our study, the mean RSV was significantly higher in males when compared to that in females. These results were similar to that reported in a previous study. In the present study, the mean RSV was 973.3 ± 105.6 mL, which was lower than the one reported by Singh et al.
In the present study, a statistically significant positive correlation was found between RSV and the initial BMI (r = 0.456). Our study substantiated the findings of Bekheit et al. and Singh et al. Csendes and Burgos stated that there were no significant differences in the anatomic measurements of the stomach between controls and patients with morbid obesity.
In our study, the mean %EWL at 6 and 12 months after surgery was found to be 47.92 ± 14.1 and 60.54 ± 16.7, respectively, which is consistent with the study conducted by Singh et al. We found a weak, nonsignificant negative correlation between RSV and %EWL at 6 months (r = −0.220) and 12 months (r = −0.148), which means the larger the volume of the resected stomach, the lower the EWL. Obeidat et al. reported that a significant correlation was observed between the RSV and %EWL at 1-year follow-up (P = 0.003). Bekheit et al. reported that multiple regression showed that the initial BMI was a predictor of %EWL at 6 and 12 months (r partial = −0.65, P < 0.0001), while the resected gastric volume was not. The results are in accordance with that of the study by Bekheit et al., but are in contrast to the findings of Obeidat et al., who reported a significant positive correlation. However, in this study, gas insufflation was used to measure the RSV as compared to saline instillation, but it is difficult to comment whether gas insufflation would change the interpretation. A comparison between the residual stomach volume and the %EWL would seem more logical, so we proceeded with the comparison. Elbanna et al. reported that the preoperative volume of the stomach positively correlated with baseline BMI, but not correlated with %EWL.
The sleeve volume in our study was found to be between 80 and 125 mL. The correlation between the volume of residual stomach and %EWL at 6 months was r = −0.010 and 12 months was r = −0.076, which was not statistically significant and contradicted with the results reported by Elbanna et al. and Hanssen et al. Perhaps, the residual volume is related to the rate of weight loss rather than the maximal weight loss. Stomach is known to be of different shapes, and it may have an impact on the volume of the resected stomach. The difference in shape would also provide a different range of the measured vertical staple line. The correlation analysis of vertical length of staple line with %EWL at 6-month and 12-month interval revealed no significance in our study.
The volume of stomach is probably the genetic status, and whether the volume gets influenced by diet or any other factors is not known. Our study shows that there was a correlation between the RSV and initial BMI. RSV forms the majority of the stomach volume. It implies that the patients with higher BMI had larger stomach volume; this may be interesting to study further.
Potential limitations of the study merit consideration. The sample size in our study was small. The duration of follow-up was short. The influence of neuro-hormonal component over stomach distensibility was not considered. The measurement of volumes of sleeve and the resected stomach was done by different methods. Hence, correlations with total volume were not done. We did not control for certain comorbidities that influence weight loss such as patient age and T2DM. We did not study the dietary and exercise pattern of the patients, which may influence weight loss. Weight loss post-LSG seems to be multifactorial and demands further multicentric research with large sample size.
| Conclusion|| |
In the present study, the RSV positively correlated with initial BMI (r = 0.456). There was no significant correlation of RSV as well as residual stomach volume with %EWL at 6-month and 12-month postoperative follow-up intervals. There was no significant correlation of vertical length of staple line with %EWL at 6-month and 12-month postoperative follow-up intervals.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Billington CJ, Epstein LH, Goodwin NJ, Hill JO, Pi-Sunyer FX, Rolls BJ, et al
. Overweight, obesity, and health risk. Arch Intern Med 2000;160:898-904.
Wang SS, Brownell KD, Wadden TA. The influence of the stigma of obesity on overweight individuals. Int J Obes 2004;28:1333.
Clapham JC. Treating obesity: Pharmacology of energy expenditure. Curr Drug Targets 2004;5:309-23.
Oviedo G, Pompetti D, Quines M, Roa C, Romero A. Effect of intragastric balloon as an alternative method for weight loosing in obese patients. Nutr Hosp 2009;24:40-5.
Yu J. Bariatric surgery and multidisciplinary treatment for obesity. Zhongguo Yi Xue Ke Xue Bao 2011;33:219-23.
Abeles D, Shikora SA. Bariatric surgery: Current concepts and future directions. Aesthet Surg J 2008;28:79-84.
Bult MJ, van Dalen T, Muller AF. Surgical treatment of obesity. Eur J Endocrinol 2008;158:135-45.
Roa PE, Kaidar-Person O, Pinto D, Cho M, Szomstein S, Rosenthal RJ. Laparoscopic sleeve gastrectomy as treatment for morbid obesity: Technique and short-term outcome. Obes Surg 2006;16:1323-6.
Givon-Madhala O, Spector R, Wasserberg N, Beglaibter N, Lustigman H, Stein M, et al
. Technical aspects of laparoscopic sleeve gastrectomy in 25 morbidly obese patients. Obes Surg 2007;17:722-7.
Vidal P, Ramón JM, Busto M, Domínguez-Vega G, Goday A, Pera M, et al
. Residual gastric volume estimated with a new radiological volumetric model: Relationship with weight loss after laparoscopic sleeve gastrectomy. Obes Surg 2014;24:359-63.
Karamanakos SN, Vagenas K, Kalfarentzos F, Alexandrides TK. Weight loss, appetite suppression, and changes in fasting and postprandial ghrelin and peptide-YY levels after Roux-en-Y gastric bypass and sleeve gastrectomy: A prospective, double blind study. Ann Surg 2008;247:401-7.
Braghetto I, Davanzo C, Korn O, Csendes A, Valladares H, Herrera E, et al
. Scintigraphic evaluation of gastric emptying in obese patients submitted to sleeve gastrectomy compared to normal subjects. Obes Surg 2009;19:1515-21.
Gagner M. Faster gastric emptying after laparoscopic sleeve gastrectomy. Obes Surg 2010;20:964-5.
Melissas J, Daskalakis M, Koukouraki S, Askoxylakis I, Metaxari M, Dimitriadis E, et al
. Sleeve gastrectomy – A “food limiting” operation. Obes Surg 2008;18:1251-6.
Baraki YM, Traverso P, Elariny HA, Fang Y. Preoperative prediction of stomach weight to be removed in laparoscopic sleeve gastrectomy procedure. Surg Technol Int 2010;20:167-71.
Obeidat FW, Shanti HA, Mismar AA, Elmuhtaseb MS, Al-Qudah MS. Volume of resected stomach as a predictor of excess weight loss after sleeve gastrectomy. Obes Surg 2014;24:1904-8.
Charan J, Biswas T. How to calculate sample size for different study designs in medical research? Indian J Psychol Med 2013;35:121-6.
] [Full text]
Moon Han S, Kim WW, Oh JH. Results of laparoscopic sleeve gastrectomy (LSG) at 1 year in morbidly obese Korean patients. Obes Surg 2005;15:1469-75.
Nahler G. Broca-formula. In: Dictionary of Pharmaceutical Medicine. Vienna: Springer; 2009.
Bekheit M, Abdel-Baki TN, Gamal M, Abdel-Salam W, Samir M, ElKayal E, et al
. Influence of the resected gastric volume on the weight loss after laparoscopic sleeve gastrectomy. Obes Surg 2016;26:1505-10.
Singh JP, Tantia O, Chaudhuri T, Khanna S, Patil PH. Is resected stomach volume related to weight loss after laparoscopic sleeve gastrectomy? Obes Surg 2014;24:1656-61.
Csendes A, Burgos AM. Size, volume and weight of the stomach in patients with morbid obesity compared to controls. Obes Surg 2005;15:1133-6.
Elbanna H, Emile S, El-Hawary GE, Abdelsalam N, Zaytoun HA, Elkaffas H, et al
. Assessment of the correlation between preoperative and immediate postoperative gastric volume and weight loss after sleeve gastrectomy using computed tomography volumetry. World J Surg 2019;43:199-206.
Hanssen A, Plotnikov S, Acosta G, Nuñez JT, Haddad J, Rodriguez C, et al
. 3D volumetry and its correlation between postoperative gastric volume and excess weight loss after sleeve gastrectomy. Obes Surg 2018;28:775-80.