Predictive Factors for Conversion After Laparoscopic Adrenalectomy

Hector R Romero, MD, Victoria Cerecedo, MD, Mauricio Sierra, MD, David Velazquez, MD PhD, Nicholas Williams, FRACS, Alexander P Heinze. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubiran

Background. Laparoscopic adrenalectomy (LA) is associated with several advantages over the open equivalent such as less postoperative pain, use of lesser dose of analgesics, decreased morbity, better cosmesis, an earlier return to work and regular activities, shorter hospital stay, reduced costs and greater patient satisfaction. However, the procedure has also been associated with limitations such as tumors larger than 6 cm, the diagnosis of pheochromocytoma or malignant lesions. There´s still ongoing debate on which is the appropriate limit for laparoscopic resection regarding tumor size. It is traditionally said that LA should be avoided if evidence of periadrenal infiltration is recognized preoperatively because invasion may compromise peripheral structures and because the capsule should remain intact. There is still very few data concerning the identification of risk factors associated to conversion. The aim of this study is to identify risk factors that may predict conversion from a laparoscopic to an open procedure.

Patients and methods From August 1991 to January 2010, a total of 133 Laparoscopic Adrenalectomies were performed at National Institute of Medical Science and Nutrition Salvador Zubirán. A retrospective analysis of variables, including tumor size, patient age, body mass index (BMI), sex, side, history of abdominal surgery and histology of tumor was performed to investigate about the risk of conversion in LA.

Results. Our population had a mean age of 39.94 ± 14.74 years (15 -78), 29 (21.8%) were men and 104 (78.2%) were women. The most frequent diagnosis was Cushing syndrome in 49 patients (36.8%) followed by after pheochromocytoma 28 (21.1%), aldosteronoma 25 (18.8%), adrenocortical cancer 2 ( 1.5%) , myelolipoma 6 ( 4.5%), metastasis 3 (2.3%) , lymphoma 3 ( 2.3%), cystic lesions 3 ( 2.3%) , amyloidosis 2 ( 1.5%), non functioning adenoma 6 ( 4.5%), paraganglioma 2 ( 1.5%), hyperplasia 3 ( 2.3%) and one (0.8%) virilizing cortical tumor. 58 (43.6%) patients had history of previous abdominal surgery. We found that 38 (28.6%) lesions developed in the right side, and 52 ( 39.1%) on left side. 43 (32.3%) were bilateral.

A total of 9 (6.8 %) laparoscopic adrenalectomies required conversion. Significant predictors of conversion according to the univariate analysis were tumor size > 7 cm, BMI >25 kg/m2 and diagnosis of paraganglioma. Multivariate analysis showed that the significant independent predictive factors for conversion were tumor size > 7 cm with a frequency of conversion of 77.8% (OR 6.641 ; 95% confidence interval 1.356- 34.42; P < 0.013), and paraganglioma with a frequency of conversion of 22.2% (OR 0.053 ; 95% confidence interval 0.026 – 0.110; P <0.004). Malignant tumors were the reason for conversion in 42.9% of the cases (OR 17.25; 95% confidence interval 3.01-98.70; P < 0.005)

Conclusion. Knowledge of tumor size, patient´s BMI and histology of the tumor should be considered predictive in terms of conversion to an open procedure. This data can be helpful in counseling our patients preoperatively.

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