The UCI Seldinger technique for percutaneous renal cryoablation: protecting the tract and achieving hemostasis.

PURPOSE: To describe our Seldinger technique of percutaneous renal cryoablation that was devised to facilitate renal biopsy, cryoprobe placement, and instillation of adjunctive hemostatics while protecting surrounding tissues from cryoinjury. PATIENTS AND METHODS: This approach was used to manage 13 renal masses in 12 adult patients. Under CT-fluoroscopic guidance, an access needle was inserted to abut the surface of the tumor, followed by an Amplatz super-stiff guidewire and a customized coaxial catheter system, which was used as a conduit for needle biopsy, cryoprobe insertion, and FloSeal instillation. In addition, a porcine model was used to compare the temperature readings adjacent to the sheathed and the unsheathed cryoprobe during percutaneous renal cryoablation. RESULTS: In all patients, the use of this access approach was accomplished without incident. Two patients needed blood transfusions. No patient had significant skin, muscle, or nerve debility. At a mean follow-up of 11 months, none had evidence of persistent disease on CT or MRI contrast imaging. In the porcine model, the customized sheath protected the surrounding tissues from reaching temperatures below 5 degrees C while temperatures down to -15 degrees C were obtained when no insulating sheath was used. CONCLUSIONS: A modified Seldinger technique enabled us to perform percutaneous renal cryotherapy through a single access channel, which facilitated access for biopsy, cryoprobe placement, and instillation of hemostatic agents. This approach may provide a protective barrier against cryogenic damage to neighboring tissues and could theoretically help minimize the chance of tract seeding.

Percutaneous and laparoscopic cryoablation of small renal masses.

PURPOSE: We reviewed our 4-year experience with percutaneous cryoablation and laparoscopy for treating small renal masses. MATERIALS AND METHODS: After institutional review board approval we retrospectively analyzed renal cryoablation procedures performed between March 2003 and October 2007. An in-depth analysis was performed concerning demographics, hospital course and short-term outcome with respect to percutaneous vs laparoscopic cryoablation. RESULTS: A total of 37 patients underwent treatment for 43 renal masses. Of the 37 patients 19 underwent laparoscopic cryoablation (24 tumors) and 18 underwent percutaneous cryoablation (19 tumors) using computerized tomography fluoroscopy. For percutaneous cryoablation a saline instillation was used in 58% of cases to move nonrenal vital structures away from the targeted renal mass. There were 5 cases of hemorrhage requiring transfusion, all of which were associated with the use of multiple cryoprobes. The transfusion rate in the percutaneous and laparoscopic cryoablation groups was 11.1% and 27.8%, respectively. Operative time was significantly longer in the laparoscopic cryoablation group compared to the percutaneous cryoablation group at 147 (range 89 to 209) vs 250.2 (range 151 to 360) minutes, respectively. The overall complication rate (including transfusion) was lower in the percutaneous cryoablation group compared to the laparoscopic cryoablation group (4 of 18 [22.2%] vs 8 of 20 [40%], respectively). Hospital stay was significantly shorter in the percutaneous vs laparoscopic cryoablation group at 1.3 vs 3.1 days, p <0.0001, respectively. Narcotic use in the percutaneous cryoablation group was more than half that used by the laparoscopic cryoablation group (5.1 vs 17.8 mg, p = 0.03, respectively). Among patients with biopsy proven renal cell carcinoma during a median followup of 11.4 and 13.4 months in the percutaneous and laparoscopic cryoablation groups, cancer specific survival was 100% and 100%, respectively, and the treatment failure rate was 5.3% and 4.2%, respectively. CONCLUSIONS: Percutaneous cryoablation is an efficient, minimally morbid method for the treatment of small renal masses and it appears to be superior to the laparoscopic approach. Short-term followup has shown no difference in tumor recurrence or need for re-treatment. Of note, hemorrhage was solely associated with the use of multiple probes.

High-frequency oscillatory ventilatory support during CT-guided percutaneous cryotherapy of renal masses.

PURPOSE: Computed tomography (CT)-guided percutaneous procedures are often made more difficult due to the movement of the kidney during respiration. Here we examine the use of high-frequency oscillatory ventilation (HFOV), which eliminates the movement of the kidney, potentially making cryoprobe access to the kidney simpler and possibly more efficient. METHODS: We compared seven CT-guided percutaneous procedures using a single cryoprobe and either standard mechanical ventilation (MV) (n=4) or HFOV (n=3). The variables studied included: total time of patient intubation, operative time, overall duration of interventional radiology (IR) suite time, change in hematocrit, narcotic use, and complications. The ease of the procedure was rated on a subjective scale from 1 to 3. RESULTS: The total intubation time remained nearly identical at 210 minutes for HFOV and 208 minutes for MV, but surgeon procedural time decreased by 31 minutes in the HFOV group (HFOV=99 minutes and MV=130 minutes) (P=0.40). Total IR time was 225 minutes for HFOV compared to 212 minutes for the MV group (P=0.63). There were no significant differences in the postoperative hematocrit, creatinine, or narcotic use between the two groups. There were no complications related to the procedure or anesthesia in either group. Both urology attending physicians and the interventional radiologist noted that the procedure seemed easier with HFOV. CONCLUSION: HFOV may shorten the actual procedural time required to perform cryoablation, likely due to the elimination of renal movement during the procedure, thereby facilitating targeting and access to the renal mass. In this initial experience, patients tolerated HFOV without incident, and the operating surgeons found it easier to perform the procedures.

Use of Yttrium-90 TheraSphere for the treatment of unresectable hepatocellular carcinoma.

This is a retrospective analysis of a new treatment modality, intra-arterial administration of Yttrium-90 TheraSphere, for unresectable hepatocellular carcinoma (HCC). Patients with HCC not amenable to surgical treatment who had satisfactory physiological function without comorbid disease or significant pulmonary shunting were eligible for treatment. Patients were categorized into complete, partial, or no response based on serum alpha-fetoprotein (AFP) levels and CT or MRI imaging. Fourteen patients were considered candidates for treatment. Three patients were excluded due to significant hepatopulmonary shunting. Eleven patients were treated with TheraSphere. One patient (9%) had a complete response, eight patients (78%) had a partial response, and two patients (18%) showed no response. Partial and complete responders with AFP-associated HCC demonstrated a median decrease in AFP levels of 79 per cent at 73 days. No patients developed liver toxicity nor died due to treatment. Five patients (45%) died of progressive disease at a median of 7 months post-treatment. Six patients (54%) were alive at a median of 11 months (range, 9 to 20 months). Okuda stage 2 and 3 patients showed a median survival of 11 months and 7 months, respectively. Yttrium-90 TheraSphere treatment for unresectable hepatocellular carcinoma is well tolerated and appears to extend survival.