William L. Newcomb

Hepatic tumor ablation with clustered microwave antennae: the US Phase II Trial

BACKGROUND Thermal ablation techniques have become important treatment options for patients with unresectable hepatic malignancies. Microwave ablation (MWA) is a new thermal ablative technique that uses electromagnetic energy to produce coagulation necrosis. We report outcomes from the first clinical trial in the United States using MWA and a 915 MHz generator. PATIENTS AND METHODS Patients with unresectable primary or metastatic liver cancer were enrolled in a multi-institutional trial from March 2004 through May 2006. Demographic information, diagnosis, treatment, and outcomes were documented. RESULTS Eighty-seven patients underwent 94 ablation procedures for 224 hepatic tumors. Forty-two ablations (45%) were performed open, 7 (7%) laparoscopically, and 45 (48%) percutaneously. The average tumor size was 3.6 cm (range 0.5-9.0 cm). Single antenna ablation volumes were 10.0 ml (range 7.8-14.0 ml), and clustered antennae ablation volumes were 50.5 ml (range 21.1-146.5 ml). Outcome variables were measured with a mean follow-up of 19 months. Local recurrence at the ablation site occurred in 6 (2.7%) tumors, and regional recurrence occurred in 37 (43%) patients. With a mean follow-up of 19 months, 41 (47%) patients were alive with no evidence of disease. There were no procedure-related deaths. The overall mortality rate was 2.3%. CONCLUSIONS Microwave ablation is a safe and effective technology for hepatic tumor ablation. In our study, clustered antennae resulted in larger ablation volumes. Further studies with histological confirmation are needed to verify clinical results.

Comparing quality-of-life outcomes in symptomatic patients undergoing laparoscopic or open ventral hernia repair.

BACKGROUND The aim of this study was to compare quality-of-life outcomes in patients with symptomatic hernias who were undergoing laparoscopic and open repairs. MATERIALS AND METHODS Clinical data for patients undergoing ventral hernia repair were reviewed with quality-of-life surveys administered before and at least 6 months following surgery. RESULTS The study included 56 symptomatic patients. Forty-one patients (73%) underwent laparoscopic repair, and 15 patients (27%) underwent open repair. There was no difference in preoperative quality-of-life scores on the SF-36 Health Survey between patients having laparoscopic or open repairs. Postoperative quality-of-life scores on the SF-36 survey were significantly improved in the laparoscopic group, compared with the open group, in general health (46% vs. 37%; P=0.0217), vitality (53% vs. 45%; P=0.0491), role-emotional (45% vs. 35%; P=0.0480), and mental health (49% vs. 39%; P=0.0381). Postoperative quality-of-life scores on the Carolinas Comfort Scale (CCS) were significantly improved in the laparoscopic group, compared with the open group, in bending over (3.15 vs. 5.87, P=0.0158), sitting up (2.51 vs. 5.13; P=0.0211), activities of daily living (2.48 vs. 5.75; P=0.0139), coughing or deep breathing (2.95 vs. 5.75; P=0.0314), walking (2.36 vs. 4.62; P=0.0427), exercising (3.19 vs. 6.14; P=0.0222), and total comfort scale (17.62 vs. 40.23; P=0.0084). CONCLUSIONS Laparoscopic ventral hernia repair provides improved quality-of-life, compared with open repair, 6 months postoperatively. Nearly all physical variables measured by the CCS were significantly better when ventral hernias were repaired laparoscopically.

Guidelines for Power and Time Variables for Microwave Ablation in an In Vivo Porcine Kidney

PURPOSE Microwave technology provides an emerging thermal ablation technique for solid organ tumors. We propose guidelines and recommend optimal time and power for use. METHODS Microwave ablations using a VivaWave Microwave Ablation System (Valleylab, Boulder, CO) were performed in vivo in a porcine kidney model. The independent variables were power (20, 30, 40, 45, 50, 60 W) and time (2, 4, 6, 8, 10, 15, 20 min) with the outcome variable diameter of ablation. Following ablations, kidneys were procured for gross and histological evaluation. Analysis of variance (ANOVA) was used followed by Tukey tests when appropriate. A P value of <0.05 was considered statistically significant. RESULTS In 308 total ablations, a minimum of 7 ablations were performed in 35 of 42 power and time variables (83%). The outcome variable, ablation diameter, was affected significantly by time, power, and time/power interaction (P < 0.0001). For each time point, a one-way ANOVA showed an overall significant difference in ablation size X wattage (P < 0.0001). Tukey tests showed that, at each time point, ablation sizes at 45, 50, and 60 W were not significantly different. After determining that 45 W was optimal, a one-way ANOVA showed an overall significant difference in ablation sizes for time points at 45 W (P < 0.0001). Tukey tests showed that, at 45 W, ablation sizes at 10 min were significantly larger than ablation sizes at 8, 6, 4, and 2 min. CONCLUSIONS We propose guidelines for use of a novel microwave ablation system and recommend use at 45 W for 10 min.

Abdominal Wall Reconstruction After Temporary Abdominal Closure: A Ten-Year Review

Abdominal wall reconstruction (AWR) is often required for hernias created after temporary abdominal closure (TAC). Demographic and clinical data from patients undergoing TAC and AWR between January 1, 1992, and December 31, 2002, were collected and univariate analysis performed. Temporary abdominal closure and AWR were performed in 21 patients. Complications developed in 12 patients (57.1%) after TAC; associated risk factors were mesh placement (P = .04) and skin grafting (P = .04). Successful AWR included mesh (n = 6), component separation (n = 6), primary repair (n = 4), and 3 combination techniques. Six patients (28.6%) developed intraoperative complications, and 14 (66.7%) developed postoperative complications. Intraoperative complications were increased in patients with tissue expanders (P = .01). Postoperative complications (P = .04) were less likely with component separation. The complication rate with TAC and AWR is high. Tissue expanders are associated with an increased risk of intraoperative complications with AWR, whereas component separation is associated with a reduction in postoperative complications.

An evaluation of electrosurgical vessel-sealing devices in biliary tract surgery in a porcine model

OBJECTIVES The purpose of this study was to evaluate two electrosurgical vessel-sealing devices in biliary surgery. METHODS Porcine common bile ducts (CBDs) were sealed with two electrosurgical devices, an electrothermal bipolar vessel-sealing device (EBVS) and ultrasonic coagulation shears. Acute study animals underwent surgical bile duct sealing followed by immediate burst pressure testing. Chronic study animals were maintained for 1 week postoperatively and then tested. RESULTS The seal failure rate in the acute study was 50% for both the EBVS device and shears, and 0% for the laparoscopic surgical clip device used as a control. The latter had significantly higher burst pressures (646.2 ± 281.8 mmHg; P = 0.006) than the EBVS device (97.6 ± 86.6 mmHg) and shears (71.7 ± 89.3 mmHg). No significant difference in burst pressures was noted between the EBVS device and shears (97.6 ± 86.6 mmHg vs. 71.7 ± 89.3 mmHg). In the chronic study, obvious bile leaks occurred in one of four pigs (25%) in the EBVS device subgroup and two of four pigs (50%) in the shears subgroup. The average proximal CBD pressure in seven pigs was 16.1 ± 4.1 mmHg. The average chronic burst pressure in the control subgroup was 1088.0 ± 922.6 mmHg. CONCLUSIONS Given the high rates of failure of the EBVS device and the shears in consistently sealing biliary ducts, we do not recommend their routine use in biliary surgery.

Safety and efficacy of the electrothermal bipolar vessel sealer in trauma

The electrothermal bipolar vessel sealer (EBVS) was developed as an alternative to sutures, clips, and the ultrasonic scalpel for haemostasis during open and laparoscopic surgery. The purpose of this prospective clinical study was to objectively evaluate the performance of the EBVS during trauma surgery. Data from trauma cases, in which the EBVS was used, was collected prospectively for 19 consecutive months. Data collected included: total number of EBVS applications, need for additional haemostatic devices after application, calculated time savings or loss, and hemorrhagic complications. The EBVS was used in 23 trauma cases consisting of 13 small bowel resections, 4 ileocolectomies, 2 left hemicolectomies, 1 transverse colectomy, 1 right hemicolectomy with roux-en-Y gastrojejunostomy and duodenostomy, 1 Hartmanns procedure, and 1 splenorrhaphy with omental injury repair. A total of 631 applications of the device were used, averaging 27.4 applications per case. An additional suture ligature or clip placed for an inadequate EBVS seal (failure) was needed in only 1.5% of the total EBVS applications. All of these (10) occurred in one patient undergoing Hartmanns procedure for massive colonic injury. An additional 45 sutures or clips for non-EBVS failure were used in 5 cases due to proximity of bleeding to critical vascular, biliary, or bowel structures. In 17 trauma cases (74%) with intestinal resection no other means of hemostasis (sutures or clips) was required except the EBVS. The mean calculated time savings using the EBVS was 26.8 min (range 9.8-48) per case. There were no haemorrhagic complications. The EBVS is safe and effective for intestinal resections and haemostasis in trauma surgery. This novel energy source reliably seals major mesenteric vessels with little need for sutures or clips. Using the EBVS can substantially shorten operative time.