Clinicopathologic differences before and after elective laparoscopic cholecystectomy according to obesity

Abstract

BACKGROUND

Although obesity is a well-established contributor to surgical risks, evidence regarding the specific outcomes of laparoscopic cholecystectomy (LC) in obese patients remains scarce.

AIM

To assess clinicopathologic differences and 1-year outcomes following elective LC in patients with obesity and gallstone disease.

METHODS

This retrospective study analyzed data from 65 patients who underwent elective LC for gallstone disease between January 2020 and May 2022, with outcomes assessed at the 1-year follow-up. Patients were categorized as obese (body mass index ≥ 25 kg/m²) or non-obese (body mass index < 25 kg/m²), and comparisons were made across preoperative laboratory values, intraoperative parameters, and patient-reported outcomes.

RESULTS

The obese group had significantly higher American Society of Anesthesiologists scores, higher glycated hemoglobin levels, and lower vitamin D levels than the non-obese group. Elevated triglycerides were more frequent in the obese group, whereas higher high-density lipoprotein levels were more common in the non-obese group. Intraoperative and postoperative outcomes did not differ between the groups. At the 1-year follow-up, 24.6% of patients reported post-cholecystectomy symptoms, with no group differences.

CONCLUSION

Obese patients had higher American Society of Anesthesiologists scores, lower vitamin D, and elevated triglycerides preoperatively, but these differences did not significantly affect intraoperative findings or 1-year postoperative outcomes compared to non-obese patients.

Key Words: Obesity; Body mass index; Laparoscopic cholecystectomy; Preoperative care; Patient outcome assessment

Core Tip: This study investigated the impact of obesity on the clinical characteristics and outcomes of patients undergoing elective laparoscopic cholecystectomy for gallstone disease. Obese patients showed distinct preoperative features, including higher American Society of Anesthesiologists scores, elevated glycated hemoglobin levels, and lower vitamin D levels; however, surgical outcomes were similar to those of non-obese patients. Postoperative care should focus on addressing obesity-related risks to improve long-term outcomes even when immediate surgical results are unaffected.

INTRODUCTION

Obesity, defined as a body mass index (BMI) ≥ 25 kg/m² for Asian populations[1], has been increasing globally, including in South Korea, becoming a significant public health concern[2]. Obesity is associated with increased surgical morbidity and mortality rates. Laparoscopic cholecystectomy (LC) is the standard treatment for symptomatic gallstones. Although obesity was once considered a relative contraindication to surgery, advances in minimally invasive techniques have shown that LC can be safely performed even in patients with a BMI ≥ 40 kg/m², offering reduced operation times, shorter hospital stays, and fewer complications compared to open cholecystectomy[2-6]. Despite this, data specifically evaluating the LC outcomes in obese patients remain limited. Obese individuals often have a high prevalence of comorbidities, highlighting the need for essential postoperative follow-up[7]. However, the perceived safety of LC may lead surgeons to underestimate the importance of long-term monitoring. Moreover, the impact of LC on the postoperative quality of life in obese patients remains unclear. Given this lack of evidence, this study aimed to assess the clinicopathological differences between obese and non-obese patients undergoing elective LC and evaluate their clinical outcomes at 1-year follow-up.

MATERIALS AND METHODS

Study design and patients

This retrospective cohort study included 65 patients who underwent elective LC for symptomatic gallstone disease or gallbladder wall thickening ≥ 4 mm between January 2020 and May 2022. Patients were categorized as obese (BMI ≥ 25 kg/m²) or non-obese (BMI < 25 kg/m²). Exclusion criteria included prior drainage procedures (e.g., endoscopic retrograde cholangiopancreatography with or without drainage and percutaneous transhepatic gallbladder drainage), emergency surgeries, or lack of 1-year follow-up. This study was approved by the Pusan National University Hospital Institutional Review Board (No. 2503-019-149), and informed consent was obtained from all participants.

Surgical procedure

All surgeries were performed by a single experienced hepatobiliary surgeon using a standardized 3-port LC technique. Prophylactic antibiotics (first-generation cephalosporins) were administered 30 min before skin incision.

Data collection

At the 1-year follow-up, patients were surveyed for surgical satisfaction, changes in digestive function, stool characteristics (including the presence of loose stools), and body weight changes (defined as a change > 2 kg).

Statistical analysis

Categorical variables were analyzed using the χ² test or Fisher’s exact test, and continuous variables were analyzed using Student’s t-test or the Mann-Whitney U test, as appropriate. Statistical significance was set at P < 0.05. All statistical analyses were performed using SPSS version 20.0 (IBM Corp., Armonk, NY, United States).

RESULTS

Preoperative clinical differences

Table 1 summarizes the preoperative characteristics of the obese (n = 31) and non-obese (n = 34) groups. There were no significant differences in age (53.2 ± 12.7 years vs 51.9 ± 14.3 years, P = 0.709) or sex distribution. The prevalence of hypertension (25.8% vs 20.6%, P = 0.598) and diabetes (12.9% vs 8.8%, P = 0.711) was also similar between groups. However, the obese group had a significantly higher proportion of patients with American Society of Anesthesiologists (ASA) scores ≥ 3 (25.8% vs 2.9%, P = 0.008), reflecting a greater burden of comorbidities. Mean glycated hemoglobin levels were significantly higher in the obese group (6.08% ± 0.68%) than in the non-obese group (5.71% ± 0.39%, P = 0.014), although this difference was attenuated when diabetic patients were excluded. Vitamin D levels were significantly lower in the obese group (23.26 ± 7.16 ng/mL) than in the non-obese group (30.91 ± 10.61 ng/mL, P = 0.035), and a higher incidence of deficiency was noted. Regarding lipid profiles, elevated triglyceride levels were observed in 41.7% of obese patients, significantly more than 10.0% seen in the non-obese group (P = 0.036). Mean high-density lipoprotein (HDL) levels were significantly lower in the obese group (42.6 ± 8.7 mg/dL) than in the non-obese group (49.2 ± 9.8 mg/dL, P = 0.011). These findings reflect the typical dyslipidemic metabolic profile of obesity, characterized by hypertriglyceridemia and reduced HDL cholesterol - both established risk factors for cardiovascular disease. Although these metabolic differences did not influence immediate surgical outcomes in our study, they highlight the importance of comprehensive preoperative risk stratification.

Table 1 Preoperative clinical characteristics of obese and non-obese patients undergoing laparoscopic cholecystectomy, %.

Variable	Obese (n = 31)	Non-obese (n = 34)	P value
Age (years)	57.9 ± 13.1	59.1 ± 11.9	0.711
Sex (M:F)	14:17	12:22	0.417
Hypertension	45.2	29.4	0.189
Diabetes	19.4	8.8	0.220
ASA score ≥ 3	25.8	2.9	0.008b
HbA1c	6.08 ± 0.68	5.71 ± 0.39	0.014a
Vitamin D (ng/mL)	23.26 ± 7.16	30.91 ± 10.61	0.035a
Elevated triglycerides	41.7	10.0	0.036a
Elevated HDL	0.0	40.0	0.011a

^aP < 0.05.

^bP < 0.01.

M: Male; F: Female; ASA: American Society of Anesthesiologists; BMI: Body mass index; HDL: High-density lipoprotein; HbA1c: Glycated hemoglobin.

Intraoperative and postoperative findings

Table 2 presents the intraoperative and postoperative data. Although the incidence of biopsy-confirmed acute cholecystitis was higher in the obese group (16.1% vs 2.9%), the difference was not statistically significant (P = 0.067). Anesthesia time was slightly longer in the obese group (106.3 ± 22.1 minutes) than in the non-obese group (92.7 ± 18.5 minutes), but this also did not reach statistical significance (P = 0.194). The length of hospital stay was similar between groups (1.61 ± 0.8 days vs 1.79 ± 0.9 days, P = 0.562). Importantly, the complication rate was higher in the obese group, although the difference did not reach statistical significance.

Table 2 Intraoperative and immediate postoperative outcomes in obese and non-obese patients, %.

Variable1	Obese (n = 31)	Non-obese (n = 34)	P value
Acute cholecystitis	16.1	2.9	0.067
Anesthesia time (minutes)	106.3 ± 49.3	92.7 ± 33.7	0.194
Hospital stay (days)	1.61 ± 1.20	1.79 ± 1.30	0.562
Intraoperative bile leak	6.5	5.9	0.924
Complications	6.5	0.0	0.132

¹Includes intraoperative data, hospital stay, and recorded postoperative.

One-year follow-up outcomes

Table 3 details the findings at 1-year follow-up. Digestive function outcomes were similar between groups. The incidence of loose stools was 22.6% in the obese group and 11.8% in the non-obese group (P = 0.245), indicating no significant difference. There were also no notable differences in body weight change between groups over the 1-year period. Overall, 24.6% (n = 17) of patients reported dissatisfaction after surgery, citing decreased digestive function (n = 12) or persistent upper abdominal discomfort (n = 4) as the primary concerns. Only one patient required regular medication for post-cholecystectomy dyspepsia. In contrast, 32.3% of patients expressed satisfaction, attributing it to improved digestion or relief of preoperative symptoms. These findings suggest that LC provides effective symptom relief for many patients, regardless of obesity status.

Table 3 One-year postoperative outcomes in obese and non-obese patients after laparoscopic cholecystectomy, %.

Variable1	Obese (n = 31)	Non-obese (n = 34)	P value
Improved digestion	16.1	20.6	0.895
Loose stools	22.6	11.8	0.245
Weight gain	29.0	20.6	0.150
Postoperative satisfaction	25.8	38.2	0.924

¹Patient responses were assessed using a standardized questionnaire addressing digestive changes, stool characteristics, and satisfaction with the surgical outcomes.

DISCUSSION

According to the World Health Organization criteria, the Asian populations exhibit a distinct relationship between BMI, body fat percentage, and health risks, including diabetes, compared to Western populations[8]. In this study, a few patients had a BMI over 30 kg/m²; therefore, obesity was defined traditionally as BMI ≥ 25 kg/m². This study primarily aimed to investigate the surgical risks associated with obesity in elective LC, which is generally considered safe. The secondary aim was to assess the changes in clinical outcomes one year after surgery based on obesity status. The ASA score is widely used to assess preoperative physical status[9]. Obesity can contribute to higher ASA scores as it is often associated with comorbidities such as hypertension, diabetes, respiratory disorders, and cardiovascular diseases[10,11]. In line with this, our findings showed a significantly higher proportion of obese patients with ASA scores ≥ 3, largely attributable to cardiovascular, pulmonary, and chronic renal diseases. Despite these preoperative differences, obesity did not adversely affect short-term surgical outcomes after elective LC.

Previous research has highlighted that obese individuals often have lower circulating vitamin D levels than non-obese individuals[12], likely because of reduced sun exposure, sequestration of vitamin D in the adipose tissue, or altered metabolism. In addition to its established role in bone health, vitamin D deficiency has been linked to an increased risk of cardiovascular disease, metabolic syndrome, diabetes, immune dysfunction, and certain cancers[13,14]. Our findings also revealed significantly lower vitamin D levels in the obese group, underscoring the need for lifestyle interventions and, where appropriate, dietary supplementation to address this deficiency. Obesity, particularly excessive visceral adiposity, is known to alter lipid metabolism, frequently resulting in dyslipidemia[15]. In our study, obese patients exhibited a significantly higher prevalence of hypertriglyceridemia and lower HDL levels than non-obese patients, consistent with the typical metabolic profile of obesity. These abnormalities are well-established risk factors for atherosclerotic cardiovascular disease and are key components of metabolic syndrome[15]. Although they did not affect intraoperative or short-term postoperative outcomes in our cohort, they may contribute to long-term cardiovascular risk. Therefore, routine lipid profiling and appropriate metabolic management should be considered during the preoperative evaluation of obese patients undergoing LC. The established association between obesity and diabetes was also reflected in our study, where obese patients showed significantly higher glycated hemoglobin levels, although the prevalence of diabetes itself did not differ significantly between the groups.

Postcholecystectomy syndrome refers to a range of symptoms that can arise following cholecystectomy, including indigestion, abdominal pain, diarrhea, and changes in bowel habits[16]. In our study, 24.6% of patients reported symptoms consistent with postcholecystectomy syndrome at the 1-year follow-up. Notably, only one patient required ongoing medical treatment for persistent indigestion, and no significant association between obesity and post-cholecystectomy syndrome was observed. Although LC is widely regarded as a safe procedure, these findings suggest that some patients may experience persistent postoperative discomfort, highlighting the importance of attentive follow-up.

Importantly, the complication rate in the obese group was higher, though not statistically significant. This finding aligns with previous reports suggesting that obesity alone does not increase the risk of perioperative complications during LC when performed under standardized protocols[3,5,6]. Despite preoperative metabolic and functional differences, obesity did not adversely affect the short-term surgical outcomes of elective LC in our cohort. Although the incidence of post-cholecystectomy symptoms did not differ significantly between obese and non-obese patients, obese individuals may be more susceptible to prolonged recovery or altered gastrointestinal function because of underlying metabolic or dietary factors[17]. Obesity is increasingly recognized as a state of chronic low-grade inflammation and metabolic dysregulation, with elevated triglycerides, insulin resistance, and reduced HDL levels commonly observed[15]. These metabolic disturbances may not affect immediate outcomes but could have implications for long-term recovery and overall health status. Clinicians should consider structured postoperative follow-up for obese patients, including nutritional counseling, weight management, and symptom monitoring[18]. Such interventions may improve patient-reported outcomes and help prevent long-term dissatisfaction after surgery. Furthermore, recent advancements in laparoscopic techniques - including the use of bariatric-specific ports, energy devices optimized for thick abdominal walls, and refined port placement strategies - have significantly improved procedural safety and efficacy in obese patients[19]. These technical improvements may account for the favorable short-term outcomes observed in our obese cohort despite their higher metabolic burden. However, this study has some limitations. The small sample size and low proportion of patients with BMI > 30 kg/m² may limit generalizability, particularly in severely obese populations. As a retrospective study, the possibility of selection bias and unmeasured confounders, such as postoperative lifestyle changes, cannot be excluded. Subgroup analyses by obesity class or age were not conducted, and the effects of metabolic interventions, such as vitamin D supplementation or lipid management, were not assessed. The 1-year follow-up period may also be insufficient to fully evaluate long-term outcomes. Despite these limitations, this study offers real-world insight into perioperative outcomes in obese patients undergoing elective LC. Larger prospective studies with extended follow-up are needed to confirm these findings and better understand the long-term impact of obesity on recovery and patient-centered outcomes.

CONCLUSION

Obesity is associated with distinct preoperative characteristics; however, it does not significantly impact immediate surgical outcomes after elective LC. Most patients experienced favorable short-term outcomes, and only a small proportion developed postcholecystectomy symptoms. These findings support the safety of elective LC in obese patients, although comprehensive postoperative care is essential to manage obesity-related comorbidities and nutritional deficiencies. Further studies are needed to explore long-term recovery outcomes and to better understand the impact of obesity on patient-centered surgical success.