Risk factors for open conversion of lateral transperitoneal laparoscopic adrenalectomy: retrospective cohort study of the Spanish Adrenal Surgery Group (SASG)

The effect of obesity on the outcomes of laparoscopic adrenal surgery in patients with Cushing syndrome

Purpose

The aim of this study is to investigate the effect of obesity on the results of laparoscopic adrenal surgery in patients with Cushing syndrome.

Methods

This retrospective study was performed in Department of General Surgery at Erciyes University School of Medicine between January 2010 and January 2023. Our analysis included Cushing syndrome patients who underwent unilateral laparoscopic adrenalectomy (LA) with the transabdominal lateral approach. All patients were evaluated in terms of age, sex, tumor diameter, body mass index (BMI), American Society of Anesthesiologists physical status classification, morbidities, surgery history, tumor side, operative time, conversion to open surgery, complications, and length of hospital stay.

Results

A total of 90 patients (75 females and 15 males) underwent a transperitoneal LA. Patients were divided into 2 groups according to their BMI: obese group (≥30 kg/m2; n = 53, 58.8%) and nonobese group (<30 kg/m2; n = 37, 41.2%). All patients were classified into 3 subgroups: obese patient group, BMI ≥30-39 kg/m2 (n = 23); morbidly obese patient group, BMI ≥40 kg/m2 (n = 14); and nonobese patient group, BMI <30 kg/m2 (n = 53). There was no significant difference in intraoperative complications, conversion to open surgery, operative time, or length of hospital stay between the groups. Only conversion to open surgery was a risk factor for postoperative complications in univariate and multivariate analyses (odds ratio, 15.4; 95% confidence interval, 1.277-185.599; P = 0.031).

Conclusion

Our results showed that LA is safe and effective in patients with Cushing syndrome with morbid obesity, allowing acceptable morbidity and length of hospital stay.

Impact of Body Mass Index ≥35 kg/m2 on Minimally Invasive Adrenalectomy

Introduction: Obesity is associated with numerous chronic conditions and an increased risk for surgical complications. Laparoscopic and robotic adrenalectomy have proven effective in the resection of adrenal tumors. This study analyzes the outcomes of severely obese patients (body-mass index [BMI] ≥35 kg/m2) following minimally invasive adrenalectomy. Materials and Methods: A retrospective analysis of patients who underwent minimally invasive adrenalectomy at our institution between 2010 and 2023 was conducted. Two matching analyses were performed. The first analysis compared patients with BMI greater versus lower than 35 kg/m2. The second analysis compared outcomes between robotic and laparoscopic adrenalectomy in patients with a BMI ≥35 kg/m2. Results: A total of 278 patients were included in the study. The median tumor size was 29 mm. Adrenal tumors had similar laterality, and most were hormonally active (66.2%). The most common pathological diagnosis was pheochromocytoma (25.5%). No statistical difference was found in peri- and postoperative outcomes between patients with BMI ≥35 and <35 kg/m2 who underwent minimally invasive adrenalectomy. When the surgical approach was compared in severely obese patients, robotic adrenalectomy was associated with shorter hospital length of stay with similar operative time as the laparoscopic approach. Conclusions: Minimally invasive adrenalectomy is safe and feasible in patients with BMI ≥35 kg/m2. Robotic and laparoscopic approaches are both safe and efficient for the resection of adrenal tumors in severely obese patients.

Development and validation of machine-learning models for the difficulty of retroperitoneal laparoscopic adrenalectomy based on radiomics

Objective

The aim is to construct machine learning (ML) prediction models for the difficulty of retroperitoneal laparoscopic adrenalectomy (RPLA) based on clinical and radiomic characteristics and to validate the models.

Methods

Patients who had undergone RPLA at Shanxi Bethune Hospital between August 2014 and December 2020 were retrospectively gathered. They were then randomly split into a training set and a validation set, maintaining a ratio of 7:3. The model was constructed using the training set and validated using the validation set. Furthermore, a total of 117 patients were gathered between January and December 2021 to form a prospective set for validation. Radiomic features were extracted by drawing the region of interest using the 3D slicer image computing platform and Python. Key features were selected through LASSO, and the radiomics score (Rad-score) was calculated. Various ML models were constructed by combining Rad-score with clinical characteristics. The optimal models were selected based on precision, recall, the area under the curve, F1 score, calibration curve, receiver operating characteristic curve, and decision curve analysis in the training, validation, and prospective sets. Shapley Additive exPlanations (SHAP) was used to demonstrate the impact of each variable in the respective models.

Results

After comparing the performance of 7 ML models in the training, validation, and prospective sets, it was found that the RF model had a more stable predictive performance, while xGBoost can significantly benefit patients. According to SHAP, the variable importance of the two models is similar, and both can reflect that the Rad-score has the most significant impact. At the same time, clinical characteristics such as hemoglobin, age, body mass index, gender, and diabetes mellitus also influenced the difficulty.

Conclusion

This study constructed ML models for predicting the difficulty of RPLA by combining clinical and radiomic characteristics. The models can help surgeons evaluate surgical difficulty, reduce risks, and improve patient benefits.

Risk factors for postoperative complications after adrenalectomy for phaeochromocytoma: multicentre cohort study

BACKGROUND

To determine the incidence and risk factors for postoperative complications and prolonged hospital stay after adrenalectomy for phaeochromocytoma.

METHODS

Demographics, perioperative outcomes and complications were evaluated for consecutive patients who underwent adrenalectomy for phaeochromocytoma from 2012 to 2020 in nine high-volume UK centres. Odds ratios were calculated using multivariable models. The primary outcome was postoperative complications according to the Clavien---Dindo classification and secondary outcome was duration of hospital stay.

RESULTS

Data were available for 406 patients (female n = 221, 54.4 per cent). Two patients (0.5 per cent) had perioperative death, whilst 148 complications were recorded in 109 (26.8 per cent) patients. On adjusted analysis, the age-adjusted Charlson Co-morbidity Index ≥3 (OR 8.09, 95 per cent c.i. 2.31 to 29.63, P = 0.001), laparoscopic converted to open (OR 10.34, 95 per cent c.i. 3.24 to 36.23, P <0.001), and open surgery (OR 11.69, 95 per cent c.i. 4.52 to 32.55, P <0.001) were independently associated with postoperative complications. Overall, 97 of 430 (22.5 per cent) had a duration of stay ≥5 days and this was associated with an age-adjusted Charlson Co-morbidity Index ≥3 (OR 4.31, 95 per cent c.i. 1.08 to 18.26, P = 0.042), tumour size (OR 1.15, 95 per cent c.i. 1.05 to 1.28, P = 0.006), laparoscopic converted to open (OR 32.11, 95 per cent c.i. 9.2 to 137.77, P <0.001), and open surgery (OR 28.01, 95 per cent c.i. 10.52 to 83.97, P <0.001).

CONCLUSION

Adrenalectomy for phaeochromocytoma is associated with a very low mortality rate, whilst postoperative complications are common. Several risk factors, including co-morbidities and operative approach, are independently associated with postoperative complications and/or prolonged hospitalization, and should be considered when counselling patients.

Predictive Factors for Conversion from Laparoscopic Adrenalectomy to Open Surgery: A 9-Year Review of 911 Cases

Background: With the development of minimally invasive techniques, laparoscopic adrenalectomy (LA) has become the standard for the treatment of adrenal surgical diseases, but conversion to open adrenalectomy (OA) is also necessary in some cases. The purpose of this study was to investigate the risk factors for conversion from LA to OA. Methods: A retrospective study was performed on 911 patients who were diagnosed with adrenal tumors and underwent LA in the Department of Urology, Second Hospital of Lanzhou University from January 2013 to December 2021. According to the surgical methods, the patients were divided into the laparoscopic group (n = 873) and the conversion group (n = 38). Logistic regression was used to analyze the independent risk factors of conversion, and the logistic regression equation was established to predict the probability of conversion. Results: In this study, 38 patients (4.17%) were converted to open. In the univariate analysis, body mass index (P = .037), tumor side (P < .001), tumor size (P < .001), surgical approach (P < .001), and histological type (P = .006) were significantly associated with conversion. In the multivariate analysis, tumor diameter >7 cm (odds ratio = 2.835, 95% confidence interval 1.096-7.335; P = .032), transabdominal approach (odds ratio = 2.400, 95% confidence interval 1.136-5.074; P = .022), pheochromocytoma (odds ratio = 5.018, 95% confidence interval 1.964-12.822; P = .001), and malignant tumor (odds ratio = 17.781, 95% confidence interval 4.156-76.075; P < .001) were independent risk factors for transition opening. The logistic regression equation showed good power to predict conversion. Conclusion: Tumor size, surgical approach, and histological type were predictive factors for conversion from a laparoscopic to an open procedure. Preoperative evaluation of these characteristics is of great value for clinicians to evaluate the risk of conversion and make a surgical plan. It can not only reduce the conversion rate but also help to improve the intraoperative situation and shorten the length of hospital stays.

Surgical treatment of large pheochromocytoma (>6 cm): A 10-year single-center experience

Objective

Clinical practice guidelines recommend open adrenalectomy (OA) for large pheochromocytoma (LPCC) > 6 cm in size. Although laparoscopic adrenalectomy (LA) for the treatment of LPCC has been reported, its role remains unclear. This study aimed to compare the effectiveness of LA and OA, and summary the surgical treatment experience.

Methods

Data concerning LPCC, from January 2010 to June 2019 of a single institution, were retrospectively reviewed. Altogether 82 patients with a tumor larger than 6 cm were included (52 patients in LA group and 30 patients in OA group). Groups were balanced by propensity score matching (PSM) into 15 pairs. Patients’ demographics, preoperative characteristics, and prognosis were analyzed.

Results

Before PSM, the OA group had larger tumor sizes (median [interquartile range, IQR]: 8.9 [7.3–10.3] vs. 7.2 [6.7–8.0] cm; p=0.000) and higher vanillylmandelic acid level (median [IQR]: 114.3 [67.8–326.4] vs. 66.6 [37.8–145.8] μmol/24 h; p =0.004) and needed a higher cumulative dose of prazosin (median [IQR]: 83.5 [37.0–154.0] vs. 38.0 [21.0–81.0] mg; p=0.028). After PSM, the baseline data showed no significant differences between both groups. The LA group had relatively more stable blood pressure in surgery, with a lower fluctuation of systolic blood pressure (mean±standard deviation [SD]: 70.9±25.1 vs. 107.4±46.2 mmHg, p=0.012) and a lower percentage of hemodynamic instability (46.7% vs. 86.7%, p=0.020). The LA group had shorter postoperative hospital stays (mean±SD: 6.4±2.7 vs. 10.1±3.4 days; p=0.003) than the OA group. Differences regarding metastasis rate (6.7% vs. 0, p=1.000) were not statistically significant between LA and OA groups. The median (IQR) follow-up time of 82 patients was 72.5 (47.0–103.5) months. Binary logistic regression showed that right-side tumors or those >8 cm in size were independent risk factors of OA.

Conclusion

LA is a safe, minimally invasive procedure for LPCC and has relatively better perioperative characteristics in large medical centers. Patients with tumors on the right side or larger than 8 cm are more likely to undergo OA initially.

A nomogram for evaluation and analysis of difficulty in retroperitoneal laparoscopic adrenalectomy: A single-center study with prospective validation using LASSO-logistic regression

BACKGROUND

While it is known that inaccurate evaluation for retroperitoneal laparoscopic adrenalectomy (RPLA) can affect the surgical results of patients, no stable and effective prediction model for the procedure exists. In this study, we aimed to develop a computed tomography (CT) -based radiological-clinical prediction model for evaluating the surgical difficulty of RPLA.

METHOD

Data from 398 patients with adrenal tumors treated by RPLA in a single center from August 2014 to December 2020 were retrospectively analyzed and divided into sets. The influencing factors were selected by least absolute shrinkage and selection operator regression model (LASSO). Additionally, the nomogram was constructed. A receiver operating characteristic curve was used to analyze the prediction efficiency of the nomogram. The C-index and bootstrap self-sampling methods were used to verify the discrimination and consistency of the nomogram.

RESULT

The following 11 independent influencing factors were selected by LASSO: body mass index, diabetes mellitus, scoliosis, hyperlipidemia, history of operation, tumor diameter, distance from adrenal tumor to upper pole of kidney, retro renal fat area, hyperaldosteronism, pheochromocytoma and paraganglioma, and myelolipoma. The area under the curve (AUC) of the training set was 0.787, and 0.844 in the internal validation set. Decision curve analyses indicated the model to be useful. An additional 117 patients were recruited for prospective validation, and AUC was 0.848.

CONCLUSION

This study developed a radiological-clinical prediction model proposed for predicting the difficulty of RPLA procedures. This model was suitable, accessible, and helpful for individualized surgical preparation and reduced operational risk. Thus, this model could contribute to more patients' benefit in circumventing surgical difficulties because of accurate predictive abilities.

Comparison of Outcomes between Obese and Nonobese Patients in Laparoscopic Adrenalectomy: A Cohort Study

INTRODUCTION

Obesity is usually considered a risk factor for surgical complications. Laparoscopic adrenalectomy has replaced open adrenalectomy as the standard operation for adrenal tumors.

OBJECTIVE

To compare the safety of laparoscopic adrenalectomy to treat adrenal tumors in obese versus nonobese patients.

METHODS

This observational cohort study analyzed consecutive patients who underwent laparoscopic adrenalectomy with a lateral transperitoneal approach at a single center (2003-2020). Data and outcomes of obese (body mass index ≥30 kg/m2) and nonobese patients were compared. To analyze the association between operative time and other variables, we used simple and multivariate linear regression.

RESULTS

N = 160 (90 obese/70 nonobese) patients underwent laparoscopic adrenalectomy. Cushing syndrome and pheochromocytoma were the most frequent indications. Obese patients were older (58 vs. 52 years, p < 0.001). A greater proportion of obese patients were ASA grade III + IV (71.1 vs. 48.6%, p = 0.004). Obesity was associated with a longer operative time (72.5 vs. 60 min, p < 0.001) and greater blood loss (40 vs. 20 mL, p = 0.022). There were no differences in conversion, morbidity, or hospital stay. After adjustment for confounding factors, operative time was positively correlated with BMI ≥30 kg/m2, learning curve, estimated blood loss, 2D laparoscopy, and specimen size.

CONCLUSION

Lateral transperitoneal laparoscopic adrenalectomy is safe in patients with a BMI 30-35 kg/m2, so these patients also benefit from this minimally invasive surgery.

Factors associated with prolonged hospital stay after laparoscopic adrenalectomy

Laparoscopy is the standard technique for resecting adrenal tumors, but short-term outcomes such as length of stay (LOS) vary widely between centers. We aimed to identify factors associated with LOS after lateral transperitoneal laparoscopic adrenalectomy (LTLA). We analyzed consecutive patients undergoing unilateral LTLA between April 2003 and April 2020. Prolonged LOS was defined as a stay longer than the 75th percentile of the overall cohort. To identify potential factors associated with prolonged LOS, we compared collected data from patients with LOS ≤ 2 days versus LOS > 2 days and elaborated multivariate logistic regression models. We included 150 patients (73 men and 77 women, median age 54 years), with benign (n = 128) and malignant tumors (n = 22). The median LOS after LTLA was 2 days; 64 (42.7%) patients had prolonged hospitalization. Variables significantly associated with prolonged LOS in the univariate analysis included ASA III + IV (p = 0.016), pheochromocytoma (p < 0.001), learning curve (p = 0.032), surgery on Thursday or Friday (p < 0.001), 2D laparoscopy (p = 0.003), operative time (p < 0.001), estimated blood loss (p < 0.001), drainage (p < 0.001), specimen size (p = 0.011), conversions (p = 0.002), complications (p = 0.019), and hospital stay (p < 0.001). After adjustment for patient, surgical, and tumor characteristics, risk factors associated with prolonged LOS in the multivariate analysis were specimen size > 9 cm (OR:13.03, p = 0.005), surgery on Thursday or Friday (OR:6.92, p = 0.001), estimated blood loss ≥ 60 ml (OR:6.22, p = 0.021), and drainage (OR:5.29, p = 0.005). Prolonged length of stay after LTLA was associated with specimen size > 9 cm, operating on Thursday or Friday, estimated blood loss ≥ 60 mL, and drainage.

Three-dimensional (3D) system versus two-dimensional (2D) system for laparoscopic resection of adrenal tumors: a case-control study

PURPOSE

Laparoscopy is the standard technique for resecting adrenal tumors worldwide. The main drawbacks of conventional 2D laparoscopy are limited depth perception and tactile feedback. Currently available high-quality 3D laparoscopy systems might improve surgical outcomes for adrenalectomy. We compare the safety and efficacy of 3D versus 2D laparoscopy in the treatment of adrenal tumors.

METHODS

This case-control study analyzed prospectively collected data from patients with benign or malignant adrenal tumors treated laparoscopically at a single academic medical center between April 2003 and March 2020. We collected demographic, diagnostic, preoperative, and operative variables, and used multiple linear and logistic regression to analyze differences in various short-term outcomes between the two approaches while adjusting for potential confounders.

RESULTS

We included 150 patients: 128 with benign tumors and 22 with malignant tumors; 95 treated with 3D laparoscopy (case group); and 55 with 2D laparoscopy (control group). After adjustment for patient, surgical, and tumor characteristics, a 2D vision was associated with a longer operative time (β = 0.26, p = 0.002) and greater blood loss (β = 0.20, p = 0.047). There was no significant difference in rates of conversion to open surgery (odds ratio [OR] = 1.47 (95% CI 0.90-22.31); p = 0.549) or complications (3.6% vs. 2.1%; p = 0.624).

CONCLUSIONS

With experienced surgeons, laparoscopic adrenalectomy was safer and more feasible with the 3D system than with the 2D system, resulting in less operative blood loss and shorter operative time with no differences in rates of conversion to open surgery or postoperative complications. For adrenal tumors, 3D laparoscopy offers advantages over 2D laparoscopy.

Comparison between retroperitoneal and transperitoneal laparoscopic adrenalectomy: Are both equally safe?

STUDY OBJECTIVES

Compare the rates of major intra- and postoperative complications, surgical conversion and mortality between transperitoneal versus retroperitoneal laparoscopic adrenalectomy.

PATIENTS AND METHODS

In a series of 344 consecutive unilateral laparoscopic adrenalectomies, performed from January 1997 to December 2017, we evaluated the rates of major intra- and postoperative complications (Clavien-Dindo≥III) and surgical conversion of the two approaches.

RESULTS

The retroperitoneal laparoscopic route was used in 259 patients (67.3%) and the transperitoneal laparoscopic route in 85 patients (22.1%). A total of 12 (3.5%) major postoperative complications occurred, with no statistically significant difference between the two approaches (P=0.7). In univariate analysis, the only predictor of major postoperative complication was Cushing's syndrome (P=0.03). The surgical conversion rate was higher in the transperitoneal route group (10/85 (11.8%) compared to 6/259 (2.3%), P=0.0003) in the retroperitoneal route group. One death occurred in each group. Independent predictors of surgical conversion in multivariate analysis included the transperitoneal laparoscopic approach (OR 1.7, 95% CI 1.3-1.9, P=0.02), advanced age (OR 1.2, 95% CI 1.1-1.6, P=0.04) and large tumor size (OR 1.3, 95% CI 1.1-1.7, P=0.01).

CONCLUSION

Both transperitoneal and retroperitoneal approaches for laparoscopic adrenalectomy are safe, with an equivalent rate of major complications and mortality. The surgical conversion rate was higher for the transperitoneal route. The retroperitoneal approach should be reserved for small adrenal lesions.