Guilherme C. Lima

Elective Laparoscopic Partial Nephrectomy in Patients with Tumors >4 cm

OBJECTIVES To assess the perioperative outcomes of elective laparoscopic partial nephrectomy to treat renal tumors in patients with tumor burdens > 4 cm compared with those with tumor burdens of < or = 4 cm. METHODS A retrospective review of medical records was performed for all patients who had undergone laparoscopic partial nephrectomy for renal tumors from January 2000 to March 2005. The preoperative risk factors (ie, sex, age, American Society for Anesthesiologists score), perioperative course (ie, operative time, estimated blood loss, warm ischemia time, intraoperative and postoperative complications, transfusion rate, intraoperative biopsy of surgical margins, length of hospitalization), and pathologic outcomes (ie, tumor stage, type, and grade) were collected and compared between the patients in the 2 cohorts. RESULTS Patients with larger tumors had significantly more complications (37.0% vs 21.8%, P = .039) and a significantly longer hospitalization (4.1 vs 3.0 days, P = .026). For those with malignant tumors > 4 cm compared with those with malignant tumors of < or = 4 cm, the complication rate was 33.3% and 11.6% (P = 0.006) and the length of hospitalization was 4.5 and 3.2 days (P = .055), respectively. No other differences were noted between the 2 groups stratified by tumor size. CONCLUSIONS Laparoscopic partial nephrectomy is an oncologically feasible option for tumor burdens > 4 cm in the greatest dimension to provide a nephron-sparing option for patients in whom individually selected lesions can be isolated.

Refining the laparoscopic retroperitoneal lymph node dissection for testicular cancer.

Since its initial description, the laparoscopic retroperitoneal lymph node dissection has evolved considerably, from a purely diagnostic tool performed to stage germ cell testicular cancer to a therapeutic operation that fully duplicates the open technique. Herein, we describe the current technique employed at our institution, along with illustrations of all surgical steps, and delineate the refinements of the technique over time.

Laser Probes for Noninvasive Coagulation of Subsurface Tissues

Previous ex vivo tissue studies utilizing deep laser heating combined with contact cooling of the tissue surface produced noninvasive thermal destruction of subsurface tissue structures in skin and liver samples. This study describes the design and preliminary in vivo testing of two integrated laser/cooling probes for simultaneous Nd:YAG laser irradiation and sapphire contact cooling of liver and skin tissues in an in vivo, acute porcine model for potential use in laparoscopic and endoscopic surgery. Nd:YAG laser radiation with a wavelength of 1.06 μm, power of 20 W, 7.5-mm-diameter spot, 500-ms pulse length, and repetition rate of 0.625 Hz, was delivered to the tissue with a total irradiation time of 16 s. The tissue surface was continuously cooled with a sapphire plate maintained at -5 oC, and with pre- and post-ablation cooling times measuring 120 s and 30 s, resulting in a total operation time of 166 s per a lesion. Thermal lesions were created in liver and skin at a 1-mm depth below the tissue surface and with a 3-4 mm diameter. The laser parameters and lesion dimensions were comparable to previous ex vivo tissue studies. Preliminary in vivo animal studies demonstrate noninvasive creation of subsurface thermal lesions in tissue using Nd:YAG laser irradiation in conjunction with sapphire contact cooling. Chronic wound healing studies will be necessary to optimize the laser and cooling parameters. Potential clinical applications include endoscopic laser treatment of female stress urinary incontinence and thermal coagulation of early stage bladder tumors.