Internal aortic annuloplasty: a novel technique.

BACKGROUND: The purpose of this study was to define an experimental model and a reproducible surgical technique for the preclinical assessment of safety and biocompatibility of a novel intra-annular internal aortic annulus repair device. METHODS: Adult sheep were implanted with HAART Inc's 19 mm aortic annulus repair device via a transverse aortotomy using standard anesthetic, surgical, and cardiopulmonary bypass techniques. Animals were closely monitored throughout the study period until the time of elective sacrifice at 30 or 60 days. RESULTS: Six adult sheep, mean age 63.2 weeks, mean weight 68.8 kg, underwent aortic annuloplasty with a 19 mm annuloplasty frame. Five of the sheep remained stable until scheduled sacrifice. The primary outcome of this study was animal mortality. Early mortality was seen in only one animal (16.7%), due to a surgical complication. Mild-to-moderate aortic insufficiency was observed in all animals upon echocardiographic examination at the time of elective sacrifice. CONCLUSIONS: Of the six animals that underwent aortic annuloplasty, there was one early death due to surgical complication. The remaining five subjects were clinically stable at the time of elective sacrifice. Any conclusions regarding the cause of the observed aortic insufficiency are beyond the scope of this feasibility study but would need to be fully evaluated in the preclinical assessment of any internal aortic annuloplasty device. We have shown that we have developed a reproducible surgical technique in a physiologically appropriate model for the preclinical assessment of internal aortic annulus repair devices.

Laser vaporization of the prostate in vivo: Experience with the 150-W 980-nm diode laser in living canines.

BACKGROUND AND OBJECTIVE: Anatomic, tissue ablation and coagulation, and histopathologic outcomes of the 150-W 980-nm diode laser selective light vaporization (SLV™) of the prostate in the first survival study of living canines were analyzed. STUDY DESIGN/MATERIALS AND METHODS: Ten dogs underwent anterograde SLV™ with the 150-W 980-nm laser delivered by its side-firing fiber (Fusion™). Postoperatively, two dogs were euthanized at 3 hours as planned, six at 2-7 days due to complications, and two, without complications, at 8 weeks as planned. Laser energy and time were recorded. Prostates were sectioned, measured, and histologically analyzed after hematoxylin and eosin (H&E), triphenyltetrazolium chloride (TTC), or Gomori trichrome (GT) staining. RESULTS: SLV™ acutely and hemostatically created a 0.6 ± 0.3 cm(3) cavity in the 3-hour group accompanied by H&E- and TTC-identified coagulation necrosis of up to 9.5 mm (6.1 ± 1.2 mm) that led to prostatic slough-induced obstruction and perforation in six of eight (75%) surviving animals, necessitating unplanned euthanasia within 2-7 days. H&E- and GT-stained prostates at 8 weeks postoperatively showed large (9.6 ± 1.4 cm(3)) re-epithelialized prostatic cavities with persistent diffuse interstitial Prostatitis and collagenous fibrosis. CONCLUSION: SLV™ with the 150-W 980-nm diode laser in living canines produced small cavities acutely, and was accompanied by deeply necrotic prostatic slough-induced obstruction and perforation in a majority of animals. A minority survived SLV and had favorable anatomic outcomes whereas histology revealed persisting inflammation. Further in vivo studies and a cautious clinical approach are recommended to finally evaluate the potential of SLV™ with the 150-W 980-nm diode laser.

Evaluation of the Rebound Hernia Repair device for laparoscopic hernia repair.

BACKGROUND: The characteristics of the ideal type of mesh are still being debated. Mesh shrinkage and fixation have been associated with complications. Avoiding shrinkage and fixation would improve hernia recurrence rates and complications. To our knowledge, this is the first study of a device with a self-expanding frame for laparoscopic hernia repair. METHODS: Six Rebound Hernia Repair Devices were placed laparoscopically in pigs. This device is a condensed polypropylene, super-thin, lightweight, macroporous mesh with a self-expanding Nitinol frame. The devices were assessed for adhesions, shrinkage, and histological examination. Laboratory and radiologic evaluations were also performed. RESULTS: The handling properties of the devices facilitated their laparoscopic placement. They were easily identified with simple x-rays. The mesh was firmly integrated within the surrounding tissue. One device was associated with 3 small adhesions. The other 5 HRDs had no adhesions. We noted no shrinkage or folding. All devices preserved their original size and shape. CONCLUSIONS: At this evaluation stage, we found that the Rebound Hernia Repair Device may serve for laparoscopic hernia repair and has favorable handling properties. It prevents folding and shrinkage of the mesh. It may eliminate the need for fixation, thus preventing chronic pain. The Nitinol frame also allowed radiologic evaluation for gross movement. Further studies will be needed to evaluate its clinical application.

Bovine pericardium buttress reinforces colorectal anastomoses in a canine model.

PURPOSE: The consequences of an anastomotic leak or disruption can be devastating, particularly in the colorectal surgery population. The purpose of this study was to evaluate and compare colon anastomoses with or without a collagen matrix buttress derived from bovine pericardium. METHODS: A circular stapler was used to create colon-colon anastomoses in a canine model. Twenty animals underwent two anastomoses each: one buttressed with bovine pericardium, and one without any reinforcement. Staple lines were evaluated at Days 0, 3, 7, 14, 42, and 84. Three animals were killed at each time interval, and evaluation included bursting pressure, bursting location, and histology. RESULTS: Colon segments with nonbuttressed anastomoses were more likely to burst at the staple line (63 percent), whereas buttressed anastomoses were more likely to burst at the adjacent intestine (74 percent; P=0.048). The burst pressure of nonbuttressed staple lines tended to be consistently, although not significantly, higher than the burst pressure of buttressed staple lines (P=0.651). At histologic analysis, the bovine pericardium buttress demonstrated an ability to allow cellular ingrowth at Day 3 and neovascularization at Day 7. There was no evidence of stenosis or infection. CONCLUSIONS: The use of a collagen matrix buttress in colorectal anastomoses was safe in a canine model. Our study indicates that true burst strength of the majority of buttressed anastomoses was greater than the adjacent intestine.