Safety and feasibility of laparoscopic adrenalectomy: What is the role of tumour size? A single institution experience.

BACKGROUND: Although, there are studies in the literature having shown the feasibility and safety of laparoscopic adrenalectomy, there are still debates for tumour size and the requirement of the minimal invasive approach. Our hypothesis was that the use of laparoscopy facilitates minimally invasive resection of large adrenal tumours regardless of tumour size.
MATERIALS AND METHODS: Within 7 years, 149 patients underwent laparoscopic adrenalectomy at one institution. The patients were divided into two study groups according to tumour size. Group 1 included patients with adrenal tumours smaller than 5 cm and group 2 included larger than 5 cm. Patient demographics and clinical parameters, operative time, complications, hospital stay and final pathology were analysed. Statistical analyses of clinical and perioperative parameters were performed using Student's t-test and Chi-square tests.
RESULTS: There were 88 patients in group 1 and 70 in group 2. There were no significant differences between study groups regarding patient demographics, operative time, hospital stay, and complications. Estimated blood loss was significantly higher in group 2 (P = 0.002). The conversion to open rate was similar between study groups with 5.6% versus 4.2%, respectively. Pathology was similar between groups.
CONCLUSION: Our study shows that the use laparoscopy for adrenal tumours larger than 5 cm is a safe and feasible technique. Laparoscopic adrenalectomy is our preferred minimally invasive surgical approach for removing large adrenal tumours.

INTRODUCTION

Laparoscopic adrenalectomy has become the preferred technique due to quick recovery, short hospital stay, less pain and better cosmetics since its introduction in 1992.[1]

The main debate in the literature involves the surgical management of patients with large adrenal tumours. Although many studies have shown that large tumours are no longer a contraindication for laparoscopic adrenalectomy,[234] some authors reported laparoscopic approach for large tumours is not feasible due to the increased risk of malignancy, especially for the tumours that show infiltration to surrounding structures on computerized tomography (CT), which can also bring other risks as peritoneal dissemination or port site recurrence.[45]

Based on our experience, we have been favouring laparoscopic approach in patients with adrenal tumours regardless of tumour size. The aim of this study was to evaluate the safety and efficacy of laparoscopy for large adrenal tumours by comparing the outcomes of laparoscopic adrenalectomy for tumours larger than 5 cm with those smaller than 5 cm.

MATERIALS AND METHODS

Patients

The study included patients who underwent laparoscopic adrenalectomy between March 2006 and July 2013 at the Division of Endocrine Surgery in our institute. The patients were divided into two study groups according to tumour size. Group 1 included patients with adrenal tumours smaller than 5 cm and group 2 included larger than 5 cm. All patients were assessed by the endocrine unit preoperatively.

Data were extracted from a prospectively maintained clinical database, and tumour properties were analysed from the patients’ pre-operative abdominal CT scans. Clinical data included age, gender, body mass index (weight in kg divided by height in m2 ), previous abdominal operations, tumour size, operative time, and diagnosis. Estimated blood loss was measured from that collected in the suction device. Operative time was measured from skin incision to the closure of the port sites.

Those patients with pre-operative imaging features of advanced malignancy, such as tumour invasion of the surrounding structures, systemic metastases or the requirement of additional open surgery were routinely performed open adrenalectomy and excluded from the study.

Surgical Technique

Our techniques for laparoscopic adrenalectomy have been described in detail before.[6] All the procedures were performed by the 2 senior authors (Selcuk Mercan and Umut Barbaros).

Statistical Analysis

Data were analysed using SPSS software version 11.0 (IBM Corporation).. Data comparisons were performed using t-test and Chi-square test. Continuous data are expressed as mean ± standard deviation. Statistical significance was reached at P < 0.05.

RESULTS

From March 2006 to July 2013 a total of 149 patients with 158 adrenal tumours underwent laparoscopic adrenalectomy at the Division of Endocrine Surgery in our institute.

The study groups were similar for age, gender, diagnosis, and tumour side [Table 1]. The mean ages were 43.8 ± 14.2 years in group 1 and 45.1 ± 12.8 in group 2. Mean tumour size of group 1 was 3.1 cm (2–5) and 7.4 cm (5–17) in group 2. There was no significant difference between study group 1 and 2 according to mean operative time (78 ± 16 min and 92 ± 24 min, P: 0.052, respectively.), however, estimated blood loss was significantly different between study groups (group 1, 55 ± 40 mL; group 2, 145 ± 95 mL). There were 6 (7%) complications in group 1 including 3 wound infections and 3 respiratory infections, and 7 (10%) in group 2 including 2 wound infections, 2 respiratory infections, 1 pancreatic fistula due to the pancreas capsule disruption and 1 urinary infection [Table 2]. The pancreatic capsular disruption was occurred at the end of the dissection in a patient with a 12 cm pheochromacytoma, and the pancreatic fistula healed spontaneously after 2 weeks. There was no mortality. The mean hospital stay was similar between study groups with 2.8 ± 2.4 days for group 1 versus 3.5 ± 3.2 for group 2. The final pathologic examination of the specimens revealed three adrenocortical carcinomas in group 1, and seven in group 2 [Table 3]. The mean follow-up period of the patients were 48 ± 20 months.

Table 1

Comparison of patient demographics

Table 2

Comparison of perioperative outcomes

Table 3

Distribution of final pathologic outcomes

DISCUSSION

In our clinic, for the surgical management of adrenal tumours, we exclusively prefer the laparoscopic technique regardless of tumour size, but we have also exclusion criteria including patients with neoplasms demonstrating clear signs of malignancy with non-respectability as well as neoplasms larger than 15 cm or patients with concomitant intra-abdominal pathologies which require open surgery.

In daily practice, we identified that in the laparoscopic technique, the dissection time was dependent on the characteristics of the tumour, but not tumour size. For the treatment of small adrenal tumours laparoscopic technique has proven its safety and efficacy, moreover, morbidity of laparoscopic adrenalectomy has been reported as lower than a conventional open technique in the literature.[7] Laparoscopic technique for large adrenal masses (>5 cm) is generally challenging, due to concerns for malignancy, technical difficulty and potential for complications. However, multiple studies have concluded that laparoscopic resection of adrenal tumours larger than 5 cm is feasible and safe in endocrine surgery specialised centres. Now-a-days, it is generally accepted that large adrenal tumours can be approached laparoscopically and converted to open if local invasion is identified during the laparoscopic procedure.[5891011]

There are debates regarding the management of adrenocortical cancer laparoscopically. In our series, there were 8 patients with adrenocortical cancer resected with clear margins laparoscopically and in 3 cases, due to invasion of the tumour we converted to open. One patient in each group has developed local recurrence at the adrenalectomy bed during the post-operative 1st year and 3 patients distant metastasis. Miller et al. reported a study comparing laparoscopic versus open resection of adrenocortical cancer in 2010. In this study, the incidence of positive margins or tumour spillage was 50% for the laparoscopic and 18% for the open group,[12] however, in another large study, Brix et al. compared a total of 152 patients undergoing the adrenalectomy with the diagnosis of adrenocortical cancer. In this study, oncologic outcomes were reported to be similar between study groups.[13] Our data revealed no significant difference in conversion to open surgery for patients with large adrenal tumours compared to smaller tumours, and also according to our data, there was no association between tumour size and hospital stay.

CONCLUSION

Laparoscopic technique is safe and feasible for adrenal tumours regardless of tumour size that as long as surgical oncologic principles, such as wide resection and keeping the capsule intact, are followed in the hands of an experienced surgeon.