INTRAOPERATIVE ULTRASOUND GUIDED RETROPERITONEAL LAPAROSCOPIC RENAL BIOPSY IN THE MORBIDLY OBESE PATIENT

Abstract

Although most renal biopsies are done percutaneously, patients with large body habitus require biopsy under direct vision. 1 Laparoscopic biopsy is an attractive alternative with reduced patient morbidity compared to an open approach. 2 In the morbidly obese patient excessive body and perirenal adipose tissue obscure usual anatomic landmarks, making trocar placement and kidney localization challenging. We describe the use of intraoperative ultrasonography in the guidance of retroperitoneal laparoscopic renal biopsy in the obese patient. METHOD A 40-year-old man, 160 cm. tall and weighing 170.5 kg., was referred by the nephrologist for laparoscopic renal biopsy to evaluate the cause of a nephrotic syndrome. He was placed in the right flank position and secured to the operating table. The standard anatomic landmarks were not palpable, making standard trocar placement hazardous. Transcutaneous ultrasonography was used to identify the 12th rib and iliac crest where an incision was made in the midaxillary line (fig. 1). A Visiport* device was introduced into the retroperitoneum under direct vision. The ultrasound probe was moved to the right upper quadrant. Using the liver as an acoustical window, transverse imaging simultaneously localized the tip of the device and the kidney (fig. 2, A). The Visiport device was guided using realtime imaging to the lateral aspect of the kidney, while simultaneously activating the blade, ensuring incision through Gerota’s fascia (fig. 2, B). The device was removed, the retroperitoneum was insufflated to 10 mm. Hg and blunt dissection with the laparoscope was performed to create a working space. A second 5 mm. trocar was placed in the anterior axillary line at the 12th rib under direct vision. The incision in Gerota’s fascia was identified and, using minimal blunt dissection, the lateral aspect of the lower pole of kidney was located 15 minutes after skin incision. Laparoscopic cup 5 mm. biopsy forceps were used to obtain 2 cortical biopsy specimens. The biopsy site was fulgurated with an argon beam laser and packed with oxidized cellulose after adequate hemostasis was confirmed and the gas was evacuated. Total procedure time was 40 minutes with minimal blood loss. The patient was discharged home within 24 hours.