Single trocar laparoscopic nephrectomy using magnetic anchoring and guidance system in the porcine model.

Purpose: We assessed the feasibility of single keyhole laparoscopic surgery using a novel transabdominal magnetic anchoring and guidance system platform in the porcine model.

Materials And Methods: A collaborative research group was formed to build a prototype system of magnetically anchored instruments for trocar-free laparoscopy. The design mandate was that the developed technology should be able to deploy into the insufflated abdomen through an existing 12 mm diameter trocar and then be moved into position in the peritoneum by manipulating external magnets.

Trocar-less instrumentation for laparoscopy: magnetic positioning of intra-abdominal camera and retractor.

Objective: To develop a novel laparoscopic system of moveable instruments that are positioned intra-abdominally and "locked" into place by external permanent magnets placed on the abdomen.

Summary Background Data: In conventional laparoscopy, multiple trocars are required because of the limited degrees of freedom of conventional instrumentation, and the limited working envelope (an inverted cone) created by the fulcrum motion around each port. While robotic systems can improve the number of degrees of freedom, they are restricted by even smaller working envelopes.

Time course of nicotinamide adenine dinucleotide diaphorase staining after renal radiofrequency ablation influences viability assessment.

Background And Purpose: Nicotinamide adenine dinucleotide (NADH) diaphorase staining has been used to confirm cell viability or death after radiofrequency ablation (RFA) of renal tissue. The time course over which NADH staining status converts from viable to non-viable after a lethal insult has not been defined for renal RFA, but the change may not be immediate. Our objective was to assess porcine renal tissue for viability using NADH diaphorase staining at various times after RFA.

Serum laboratory values following uncomplicated laparoscopic urological surgery.

Purpose: Presentation of complications following laparoscopic surgery can be different from corresponding open surgical complications. While leukopenia has been identified as a common finding in patients with unrecognized bowel injury following laparoscopy, to our knowledge no study has determined if leukopenia or other serum abnormalities are unique to patients with laparoscopic complications. We present an analysis of postoperative laboratory values from patients after uncomplicated urological laparoscopic surgery.

Training for renal ablative technique using an agarose-based renal tumour-mimic model.

Objective: To assess whether a recently developed porcine tumour-mimic model can serve as a training model for radiofrequency ablation (RFA) of renal masses, as the increased diagnosis of small occult renal masses has led to the development of nephron-sparing treatments, including RFA, and the techniques required for effective tumour ablation can be difficult to master.

Materials And Methods: Tumour mimics were created by injecting 0.7 mL of an agarose mixture into the parenchyma of a porcine kidney, producing 1-cm spherical lesions which were hyperechoic on ultrasonography (US).

Effect of warmed, humidified insufflation gas and anti-inflammatory agents on cytokine response to laparoscopic nephrectomy: porcine model.

Purpose: We evaluated the effects of warmed, humidified CO2 and anti-inflammatory agents on the local and systemic cytokine response after laparoscopic nephrectomy.

Materials And Methods: A total of 15 pigs were randomized to undergo standard laparoscopic nephrectomy, laparoscopic nephrectomy with warmed, humidified CO2 gas or laparoscopic nephrectomy with perioperative administration of intravenous dexamethasone and oral rofecoxib. At baseline, and 1, 4, 24 and 48 hours after surgery duplicate blood and peritoneal samples were drawn to analyze cortisol, glucose, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta and IL-6 via a microassay technique.

Renal radiofrequency ablation: technique and results.

Laparoscopic or percutaneous radiofrequency ablation has become a viable treatment option for small renal tumors. Although long-term results are not yet available, intermediate results show promise for the treatment of select renal lesions. Here, we describe the basics of radiofrequency ablation technology, outline techniques used for both percutaneous and laparoscopic treatment routes, and provide a brief review of clinical results to date.

Application of novel hemostatic agent during laparoscopic partial nephrectomy.

Purpose: We determined if QuikClot, a novel hemostatic agent made of a granulated mineral substance, could be used to control renal parenchymal bleeding and collecting system leakage during open and laparoscopic partial nephrectomy.

Materials And Methods: After obtaining renal hilar vascular control 2 domestic female pigs underwent bilateral open and 4 underwent unilateral laparoscopic partial nephrectomy. After excision of the lower pole without cautery the hemostatic agent was applied to the cut surface of the kidney and hilar vascular control was released.

Retrograde renal cooling during radio frequency ablation to protect from renal collecting system injury.

Purpose: We evaluated the protective effect of continuous retrograde irrigation of ice-cold saline on the renal collecting system during central parenchymal temperature based radio frequency ablation (RFA).

Materials And Methods: In 10 domestic pigs bilateral, centrally located renal parenchymal RFA lesions (intended 2 cm in diameter) were created that intentionally involved the collecting system. RFA probe placement was guided by fluoroscopy with retrograde collecting system opacification and simultaneous direct laparoscopic visualization.

Short-term efficacy of temperature-based radiofrequency ablation of small renal tumors.

Objectives: To present our experience using radiofrequency ablation (RFA) for the treatment of small renal tumors. Our objective was to assess the short-term (1 to 3 years) oncologic efficacy of RFA.

Methods: Consecutive renal tumors treated since May 2001 with a minimal follow-up of 6 months were included.

Contrast-enhanced ultrasound evaluation of radiofrequency ablation of the kidney: reliable imaging of the thermolesion.

Background And Purpose: Radiofrequency ablation (RFA) is limited by the inability to monitor progression of the thermal lesion. Contrast-enhanced ultrasonography (CEUS) imaging has considerable potential as a monitoring modality for RFA. We report our experience using CEUS to evaluate the lesion produced by RFA in a porcine model.

Acute histologic effects of temperature-based radiofrequency ablation on renal tumor pathologic interpretation.

Objectives: To describe the histopathologic changes and evaluate the interpretability of human renal tumor specimens obtained after temperature-based radiofrequency ablation (RFA).

Methods: RFA of 119 solid kidney tumors was performed percutaneously under computed tomography guidance, laparoscopically or during open surgery, using a temperature-based system. Of the 119 tumors, 70 were biopsied (two or more samples) after RFA, 39 immediately before ablation, and 10 were not biopsied.

Development of a renal tumor mimic model for learning minimally invasive nephron sparing surgical techniques.

Purpose: New laparoscopic partial nephrectomy and tumor ablation techniques are continuously being developed and evaluated in large animal models. However, to our knowledge no reliable renal tumor model exists to evaluate procedure efficacy. We developed and assessed the reliability of a tumor mimic model to serve as a training tool for minimally invasive kidney surgery.

The radiographic evolution of radio frequency ablated renal tumors.

Purpose: Radio frequency ablation (RFA) of renal tumors is a relatively new technology. Few groups are familiar with the posttreatment appearance of these lesions and how they differ from cryoablated renal masses. We describe the evolution of the appearance of these lesions on followup contrast enhanced (CE) computerized tomography (CT).

Radiofrequency interstitial tumor ablation: dry electrode.

With the shift in the treatment of small renal tumors from radical extirpative surgery to nephron-sparing approaches, dry-electrode radiofrequency ablation (RFA) has emerged as one potential modality. This application of RF energy leads to the production of heat within the treatment zone secondary to the native impedance of living tissue. Animal studies and human clinical series have demonstrated that RFA can create controlled, targeted, reproducible, and lethal lesions.

Nephrectomy after radiofrequency ablation-induced ureteropelvic junction obstruction: potential complication and long-term assessment of ablation adequacy.

Little information is available concerning the morbidity of radiofrequency ablation (RFA) or the evolution of an RFA lesion over time. We report our findings in a kidney removed 1 year after RFA of a 2.3-cm renal tumor.

Feasibility of laparoscopic partial nephrectomy using pledgeted compression sutures for hemostasis.

Purpose: To develop a technique for laparoscopic partial nephrectomy (LPN) without the use of hilar occlusion that allows large renal resection and excellent hemostasis.

Materials And Methods: Five female domestic pigs underwent right laparoscopic transperitoneal lower-pole partial nephrectomy after placement of pledgeted parenchymal compression sutures tied intracorporeally to induce regional renal hypoperfusion. Postoperatively, serial serum creatinine measurements were obtained to monitor renal function.

Laparoscopic partial nephrectomy with a diode laser: porcine results.

Purpose: To develop a safe and effective technique for laparoscopic partial nephrectomy without need for hilar occlusion.

Materials And Methods: Laparoscopic transperitoneal lower-pole partial nephrectomy was performed in five 45- to 50-kg female farm pigs using a 980-nm diode laser. Standard transperitoneal access was obtained, and a four-port approach was used to perform a laparoscopic right partial nephrectomy using a diode laser (23 W) without hilar occlusion.

Minimally invasive management of the small renal tumor: review of laparoscopic partial nephrectomy and ablative techniques.

The most profound change among the many that have occurred in the management of renal-cell carcinoma (RCC) in recent years is the advent of nephron-sparing surgery for masses <4 cm. The main challenge now is to reduce the morbidity associated with such procedures. Because of the problems in obtaining hemostasis, only a few highly experienced surgeons are performing partial nephrectomy laparoscopically.

Laparoscopic application of radio frequency energy enables in situ renal tumor ablation and partial nephrectomy.

Purpose: To our knowledge we present the initial series of renal mass in situ laparoscopic radio frequency ablation. We also discuss the indications for and results of subsequent laparoscopic partial nephrectomy.

Materials And Methods: Laparoscopic radio frequency ablation was performed in 13 patients with a mean age of 59 years (range 18 to 81) and a total of 17 small enhancing renal masses.

Percutaneous radiofrequency ablation of renal tumors: technique, limitations, and morbidity.

Objectives: To evaluate our evolving experience with percutaneous radiofrequency (RF) renal tumor ablation and focus on our technique to ensure maximal treatment efficacy and reduce the possibility of complications.

Methods: Fifteen patients with small (less than 4 cm) posterior or lateral contrast-enhancing (more than 10 Hounsfield units) renal tumors were candidates for RF treatment. Of these patients, 12 (13 tumors) received computed tomography-guided percutaneous RF ablation.

Laparoscopic versus open retroperitoneal lymph node dissection: a cost analysis.

Purpose: Laparoscopic retroperitoneal lymph node dissection is significantly less morbid than open retroperitoneal lymph node dissection but it is generally more costly due to longer operative time and disposable equipment. In response to budgetary pressure at our large county hospital we identified the cost components of laparoscopic retroperitoneal lymph node dissection that could be targeted to decrease procedure costs before expanding our laparoscopic retroperitoneal lymph node dissection program.

Materials And Methods: A comprehensive literature review of open and laparoscopic retroperitoneal lymph node dissection was performed and certain parameters were abstracted, including operative time and equipment, hospital stay, perioperative complications and surgical success rates.