Endourology / Laparoscopy (1) - Part 2

95

MAGNETIC POSITIONING SYSTEM FOR TROCARLESS LAPAROSCOPIC INSTRUMENTS

Linda BAKER, Robert EBERHART*, Raul FERNANDEZ†, Richard BERGS† and Jeffrey CADEDDU

University of Texas Southwestern Medical Center at Dallas, Urology, Dallas, USA - * University of Texas Southwestern Medical School at Dallas, GI/Endocrinology, Dallas, USA - † University of Texas at Arlington, Automation & Robotics Research Institute, Fort Worth, USA

PURPOSE: Trocars limit laparoscopy by creating a fixed working envelope. Additional ports aid instrument position, visibility and efficiency but may introduce pain, and risk bleeding or organ damage. To circumvent these issues, a novel laparoscopic transabdominal magnetic positioning system (MPS) and tool platform was developed, allowing unrestricted movement of a magnetically anchored intra-abdominal camera and tissue retractor.

MATERIAL AND METHODS: We engineered, fabricated, and functionally tested in a porcine model the MPS with a custom-designed intra-abdominal laparoscopic camera and liver/spleen retractor. Both are introduced via one umbilical 12mm laparoscopic trocar, and coupled across the abdominal wall by a surgeon-controlled extracorporeal magnet. The MPS thus allows the surgeon to extracorporeally magnetically ‘steer’ the trocar-less intracorporeal tool to any location on the ventral abdominal wall.

RESULTS: Functionally adequate magnetic lifting forces at both 1 and 2 cm wall thickness were 850 g and 350 g, respectively and short term use was not associated with tissue damage by histological analysis. The MPS with custom camera and retractor performed well, permitting 3 porcine laparoscopic nephrectomies using only a 5 mm and custom lighted 12 mm trocar (left and right hand working instruments only).

CONCLUSIONS: Our novel MPS and tool platform is capable of securely and flexibly supporting prototype tissue retractors or cameras across a porcine abdomen. Laparoscopic porcine surgery utilizing only 2 trocars is feasible. Further refinements, including robotic technology, will facilitate the development of an array of clinically relevant trocar-less laparoscopic instruments.

96

ANTEROLATERAL APPROACH FOR RETROPERITONEOSCOPIC RENAL SURGERY

Venkata JAYANTHI

Columbus Children's Hospital, Urology, Columbus, USA

PURPOSE: Traditional retroperitoneoscopic renal surgery involves a lateral or posterior approach to the kidney. We describe an anterolateral approach which may offer some advantages, especially for those with little prior laparoscopic experience.

MATERIAL AND METHODS: Technique: A 1 cm incision is made 1 cm above the iliac crest. After retroperitoneal balloon distention, a camera port is placed and retroperitoneoscopy performed. Two 5 mm ports are placed under direct vision anteriorly and posteriorly at the ends of what would be a standard flank incision. This port placement allows dissection analogous to that performed via an open exploration.

RESULTS: Forty-one patients underwent a retroperitoneoscopic renal procedure. Twenty-seven underwent pyeloplasty and 14 underwent nephrectomy. There was only one open conversion, a boy with UPJ obstruction and dense adhesions related to prior renal trauma. Ages ranged from 1 to 20 years (mean 7.8). Inadvertent peritoneal tears occurred in 15 patients, mostly early in the series. The resulting pneumoperitoneum did not preclude successful completion of the procedure in any case, although some did require placement of a 4th port for peritoneal retraction.

CONCLUSIONS: The anterolateral approach is useful for those with little prior laparoscopic surgery because the exposure and dissection is identical to that performed with a standard flank incision. This is beneficial during pyeloplasty where aberrant vessels are typically located anterior to the UPJ. Ports are placed relatively far apart allowing surgical instruments to have greater mobility with less fighting. The main disadvantage with this approach is the potential for peritoneal tears.

97

SINGLE LAPAROSCOPIC PORT ASSISTED INSERTION OF PERITONEAL DIALYSIS CATHETERS IN CHILDREN

Irene MILLIKEN, Arvind NAGRA*, Maggie FITZPATRICK* and Ramnath SUBRAMANIAM

St James University Hospital, Dept Paediatric Urology, Leeds, UNITED KINGDOM - * St James University Hospital, Dept Paediatric Nephrology, Leeds, UNITED KINGDOM

PURPOSE: To assess the effectiveness and complication rate in laparoscopically placed peritoneal dialysis catheters (PDC) using the single port technique.

MATERIAL AND METHODS: This is a prospective study conducted from 2002 to 2004. Children with established renal failure requiring insertion of PDC were included. The insertion was performed by a single surgeon using a single port laparoscopic technique. Partial omentectomy was performed and the catheter accurately placed in the pelvis under vision. The catheter could then be used immediately post operatively.

RESULTS: Twenty-two children (13F:9M) with a mean age of 9 years (1.0-17.5) had PDC inserted laparoscopically between 2002 and 2004. Indications included renal dysplasia, reflux nephropathy, HSP nephropathy, IgA nephropathy, atypical HUS, FSGS and congenital nephritic syndrome. Mean time for insertion was 26 mins (23-29). 10 (45%) catheters were used within 4 hours. Early complications include a minor leak that resolved within 24 hours, 1 exit site infection that resolved with oral flucloxacillin, 1 blockage due to a fibrin clot that resolved with urokinase and 1 blocked after 2 weeks due to adhesions (not omentum) and was revised.

CONCLUSIONS: Laparoscopic insertion of PDC allows accurate placement of the catheter under direct vision, immediate use post operatively with minimum morbidity and good cosmesis. We found that laparoscopic insertion using the single port technique was a safe, effective and quick technique for use in children.

Read Endourology / Laparoscopy (1) Selected Abstracts - Part 1

email news signup