Hendricus J. Mansvelt Beck

Nonocclusive excimer laser-assisted end-to-side anastomosis

BACKGROUND High-flow extraintracranial bypass operation on the brain is a risky procedure because of the temporary occlusion of the intracranial portion of the internal carotid artery. We therefore developed a nonocclusive anastomosis technique in the experimental animal laboratory in 100 chronic and acute experiments in rabbits. METHODS In 40 patients we interposed a venous transplant between the external carotid artery or one of its branches and the intracranial portion of the internal carotid artery. During the construction of the distal anastomosis the recipient artery was not occluded. The donor vessel was stitched to the exterior of the recipient vessel and an Excimer laser catheter (Medolas GmbH, Amberg, Germany) was introduced by way of an artificial side branch. The tip of the laser catheter created a hole in the wall of the recipient artery just inside the anastomosis. The cut-out full-thickness portion of recipient vessel wall remained attached to the tip of the laser catheter by way of high vacuum suction and was removed together with the laser catheter. The artificial side branch was occluded with a hemostatic clip. No interruption of blood flow in the recipient artery was induced during the making of the anastomosis. RESULTS The procedure was well tolerated by the patients and a high patency rate was observed. CONCLUSIONS The nonocclusive Excimer laser-assisted anastomosis technique is safe and yields a high long-term patency rate in neurosurgical patients. It cannot be excluded that there are indications for this method in coronary bypass surgery.

Endoscopic Exposure and Stabilization of Posterior and Inferior Branches Using the Endo-Starfish Cardiac Positioner and the Endo-Octopus Stabilizer for Closed-Chest Beating Heart Multivessel CABG: Hemodynamic Changes in the Pig

Background—Closed-chest, off-pump, multivessel CABG requires modified instruments to expose and stabilize posterior and inferior coronary branches. Using three new prototype devices, we explored the feasibility of endoscopic bypass grafting on these branches and assessed cardiac function during cardiac displacement. Methods—Eight pigs (75 to 85 kg) were instrumented for hemodynamics and paced at 80 to 100 bpm. After closure of the sternotomy wound, the Da Vinci endoscope was inserted subxiphoidally. A sternal hook was used to hoist the sternum ventrally by 5 cm. The articulating EndoStarfish cardiac positioner was placed through a trocar (Ø12 mm). The positioner was fixed to the apex using −400 mm Hg suction and the heart was displaced anteriorly to 90 degrees. In 12 other pigs (75 to 85 kg), both internal mammary arteries (IMA) were harvested and the sternal wound was closed. Five trocar ports were placed for instrumentation (Ø12 mm, two in left chest, two in right chest, and one subxiphoidally). For coronary stabilization, a novel deployable EndoOctopus cardiac stabilizer was employed (suction −400 mm Hg). The Da Vinci robot-telemanipulator system was used for endoscopic grafting of the left and right IMA on posterior and inferior branches (16 anastomoses). Results—When circumflex arteries were fully exposed and accessible for coronary surgery, stroke volume decreased by 18%±3 versus baseline (P =0.02) and mean arterial pressure decreased by 27%±6 (P =0.001). Additional 10 degrees Trendelenburg head-down positioning normalized stroke volume and arterial pressure. In the displaced heart, obtuse marginal branches (OM) and the ramus descending posterior (RDP) of the right coronary artery became fully exposed with a mean arterial pressure >70 mm Hg during grafting. No accidental detachment occurred. Coronary target motion was restrained to approximately 1×1 mm. In two test cases, five sham distal anastomoses were created (grafts sewn to epicardium, left IMA to OM2 jump to OM3, right IMA to RDP, and composite graft from left IMA jump to diagonal branch). In 10 animals, 16 successfully completed anastomoses to RPD and OM branches of Ø1.75 to 2.5 mm required 25 to 60 minutes each to construct. At sacrifice, all anastomoses were patent. Conclusion—In the closed-chest pig in Trendelenburg position and during lifting of the sternum, the EndoStarfish and EndoOctopus enabled IMA grafting of posterior and inferior branches on the beating heart without mean arterial pressure dropping below 70 mm Hg.

Sutureless nonocclusive bypass surgery in combination with an expanded polytetrafluoroethylene graft. Laboratory investigation.

OBJECT Cerebral aneurysms that cannot be treated by clip or coil placement can be treated with high-flow bypass surgery using techniques such as the excimer laser-assisted nonocclusive anastomosis (ELANA). To simplify the technique, a sutureless ELANA (SELANA) was developed in combination with an expanded polytetrafluoroethylene (ePTFE) graft. METHODS In 18 rabbits a bypass was constructed on the abdominal aorta using the SELANA technique with an ePTFE graft, resulting in 18 bypasses and 36 anastomoses. Short-term effects were analyzed in the first 2 weeks and at 2 and 3 months after the procedure. Patency was evaluated using quantitative ultrasound flowmetry. The anastomotic sites were studied using scanning electron microscopy. RESULTS Construction of the bypass using the SELANA technique was easier and faster (15-25 minutes) compared with bypasses made with the ELANA technique (> 90 minutes). At the end of follow-up, 16 of 18 bypasses were patent. Of 36 SELANA anastomoses, 32 could be completed without short temporary occlusion of the recipient vessel. Scanning electron microscopy showed complete coverage of all anastomoses with neointimal repair tissue after 10 days. CONCLUSIONS The SELANA technique provides further advantages over the conventional ELANA technique in ease of use and shortening of procedure time. The patency rate in this series was 89% and neointima repair tissue at the anastomosis site was complete after 10 days. Further experimental studies of the long-term patency and safety of this technique are necessary before clinical application.

Facilitated Exposure of the Internal Mammary Artery in Minimally Invasive Direct-Vision CABG

A method is described to facilitate harvesting of the mammary artery in minimally invasive direct-vision coronary artery bypass grafting using a 10-cm anterior thoracotomy. Hoisting of the anterior thoracic wall with a modified retractor allows good exposure. Harvesting the mammary artery without the use of endoscopic tools was successful in all 10 cases.