Clip Device Research Articles

A new clip device for the construction of vascular interrupted anastomoses in congenital cardiac surgery.

Many different mechanical vascular anastomotic devices have been developed recently, mostly rigid stenting mechanisms applicable only in coronary artery bypass grafting surgery. U-Clips, however, allow the precise construction of any vascular interrupted anastomosis, preserving pulsatility and perhaps growth potential. We report the first use worldwide of U-Clips for congenital cardiac surgery in 10 pediatric patients (mean age, 2.3 +/- 1.7 years). The operations took place between July 2001 and July 2002 for coarctation repair (3 patients), Glenn shunt (5 patients), Blalock-Taussig shunt (1 patient), and arterial switch (1 patient). Device handling, primary hemostasis, and patency were excellent, and no device-related complications occurred. Because of the learning curve, aortic cross-clamp times were significantly longer for the repair of coarctation with U-Clips than with the running-suture technique (21.7 +/- 2.3 minutes versus 14.4 +/- 2 minutes; P = .012). Postoperative recoveries were uneventful in all patients except for a baby with pulmonary atresia with intact ventricular septum, who died after 62 days. After a mean follow-up period of 11.9 +/- 4.4 months, echocardiographic controls of all anastomoses showed nonturbulent flow without any restriction. The U-Clip device may be a useful adjunct in congenital cardiac surgery for facilitating the creation of interrupted vascular anastomoses. Further evaluation is warranted for determining the long-term benefits of these devices with respect to growth preservation and restenosis.

Facilitated vascular interrupted anastomosis in cardiovascular surgery with a new clip device

J Thorac Cardiovasc Surg 2002;124:1256-8

Creation of Native Arteriovenous Fistulas with Interrupted Anastomoses Using a Self-Closing Clip Device - One Clinic's Experience

The nitinol U-CLIPTM Anastomotic Device (Coalescent Surgical, Inc., Sunnyvale, CA) is a self-closing penetrating vascular clip that reduces suture management and eliminates knot tying, thus enabling rapid and precise interrupted suture placement and facilitating creation of an optimal vascular anastomosis. This report describes the use of U-CLIP devices in the surgical creation of native arteriovenous fistulas in 68 chronic hemodialysis patients. Overall, 61 of the 65 fistulas created matured successfully within 8-9 weeks. Radial cephalic fistulas: 93% were mature at 8 weeks. Brachiocephalic fistulas: 69% were mature at 8 weeks. One-stage basilic vein transposition: 100% were mature at 9 weeks. Two-stage basilic vein transposition: 100% were mature at 8 weeks after second stage. The results in this report show the excellent performance of U-CLIP vascular clips in the creation of several types of native arteriovenous fistulas in chronic hemodialysis patients. The fistulas created using the U-CLIP devices had a high maturation rate within a relatively short time period, and provided uniformly high flow rates. The patients in this study were a challenging population, with a high incidence of diabetes mellitus (81% of the patients) and vein sizes that were smaller than typically used for fistula creation. The U-CLIPTM Anastomotic Device offers the opportunity to create superior interrupted anastomoses for AV fistulas, even in patients who would otherwise be considered poor candidates for fistula creation.

4740 The mucosal clip assisted method for the placement of percutaneously placed jejunal enteral tubes is safe and effective.

Jejunal enteral tubes (JET) are often placed as an extension of the percutaneous gastrostomy tube in debilitated patients(pts) who are at high risk for aspiration. Proximal migration into the stomach due to friction between the endoscope (EGD) and the JET often occurs. Thus, procedural time may be increased and repeat EGDs may be required. The literature is sparse regarding the MCAM technique. A total of 9 pts; 8 had naso-jejunal tubes and 1 a JET/PEG with successful placement in 83% and an average procedure time of 30 minutes (GIE 1994;40:220-22 & JPEN 1996;20:306-8). The objective is to determine if MCAM: 1) is effective in delivering and keeping the JET in place in the descending duodenum (DD), 2) involves less procedural time, 3) prevented less proximal migration of the JET and 4) is safe and without complications. We prospectively used this method in 31 pts. There were 19 males. 34 total EGDs were performed. The major indications were: neurologic deficits, cancer and dysphagia. A Bard or Microvasive 20F G-tube was placed using the Ponsky-Pull Method. A 9F JET with a distal suture was then placed through the G-tube. The suture was grasped with the Olympus mucosal clip (MC) device, closed and pulled back into the standard upper EGD. The EGD and the JET were placed as far down in the DD. The MC was deployed between the suture loop and fastened to the duodenal wall. X-rays (KUB) were obtained to confirm placement. The procedure time, number of attempts, timing of feeding and complications were assessed. Results: The mean procedure time was 23.5 minutes. Only 1 attempt was required in 94% (32/34) and 2 attempts in 6%(2/34). Feeding was initiated within 24 hrs in 44% (15/34) and after 24 hrs in 56% (19/34) pts. JET migration occurred in only 2 pts requiring repeat EGD. 24/34 cases had at least 2 KUBs confirming JET placement. Conclusion: The MCAM method is technically simple, well tolerated and is a reliable method of performing a JET/PEG. In addition to lowering the aspiration risk by securing the JET to the duodenal wall, feedings may be initiated on the same day. No complications of ulcerations, bleeding or perforation occurred. A randomized trial comparing the MCAM with the conventional method is required to determine its true efficacy, costs and ease of use.

Digital sonomicrometer system for measuring small vascular diameters in situ.

Although present sonomicrometer techniques for measuring continuous changes in vascular diameter are very useful, two problems with available methods are difficulty in maintaining crystal alignment throughout an acute experiment and inability to measure absolute dimensions less than 1 mm. We have designed and ultrasonic dimension gauge system to over come these problems. The design uses a gate to pass a 20 MHz signal to a counter during the sonic travel time between crystals, and then converts the digital count to an analogue voltage. Interference from the transmitting impulse in the received signal was minimised using MOSFET transistors allowing measurements of absolute dimensions from 0.00 mm to 99.9 mm. An averaging effect which depends upon the asynchrony between the basic timer and the counter clock results in a resolution of at least 10 μm. Repeated calibration curves showed an accuracy of 2.5 μm without significant bias. Piezoelectric crystals were mounted to a lighweight stainless-steel clip to facilitate attachment to the vessel and to maintain the crystals in focus during changes in diameter. Mean and phasic diameters measured in the femoral artery with the clip device correlated well with measurements obtained with crystals sewn to the adventitia of the femoral artery of the dog (slope =0.97, r=0.99).

Methyl methacrylate stent for prevention of postexcisional recurrent ear keloid

Compared with other available treatment modalities that rely on active pressure over the excised region, this method of therapy works by confinement of the soft tissue to the internal dimensions of the stent. It minimizes the possibility of creating excessive force that could cause an unfavorable response such as inflammation or necrosis. One advantage of this design is that the stent can be used for the treatment of either an helix or earlobe keloid, while the button or clip devices cannot be used in the helix because of its wavelike configuration (Fig. 15).