Side-to-side sutureless vascular anastomosis with magnets

OBJECTIVE: Abbe and Payr introduced vascular techniques and devices to facilitate vessel anastomosis over a century ago. Obora published the idea of a sutureless vascular anastomosis with use of magnetic rings in 1978. The purpose of this study was to assess the performance of a new magnetic device to perform a side-to-side arteriovenous anastomosis in a dog model. MATERIAL AND METHODS: Male fox hounds (25 kg) were treated preoperatively and daily postoperatively with clopidogrel bisulfate (Plavix) and aspirin. The femoral artery and vein were exposed unilaterally in 3 dogs and bilaterally in 4 dogs (n = 11 anastomoses). A 4-mm arteriotomy was performed, and 1 oval magnet 0.5 mm thick was inserted into the lumen of the artery and a second magnet was applied external to the artery, compressing and stabilizing the arterial wall to create a magnetic port. An identical venous magnetic port was created with another pair of oval magnets. When the 2 ports were allowed to approach each other, they self-aligned and magnetically coupled to complete the arteriovenous anastomosis. Patency was assessed for the first hour with direct observation, again after 9 weeks with duplex ultrasound scanning, and at 10 weeks under direct open observation. The anastomoses were explanted after 10 weeks. Hydrodynamic resistance was measured ex vivo on the final 8 anastomoses by measuring the pressure drop across an anastomosis with a known flow rate. RESULTS: After implantation, very high flow created visible turbulence and palpable vibration. All 11 anastomoses were patent under direct observation and palpation. Ten of 11 anastomoses were clearly patent on duplex scans, and patency of 1 anastomosis was questionable. Hydrodynamic resistance averaged 0.73 +/- 0.33 mm Hg min/mL (mean +/- SEM). CONCLUSIONS: Vascular anastomoses performed with magnets demonstrated feasibility; exhibited 100% patency after 10 weeks in a dog arteriovenous shunt model; lacked apparent aneurysm or other potentially catastrophic failure; demonstrated remodeling of the vessel wall after several weeks to incorporate the magnets, making the magnetic force unnecessary; and warrants further study in vessels with different sizes, flow rates, and locations. CLINICAL RELEVANCE: We present a magnet-based device used to perform side-to-side peripheral vascular anastomoses. Its advantages include the ability to anastomose vessels without requiring circumferential surgical exposure. Vascular anastomosis performed with these magnets demonstrated 100% patency in the dog, lacked apparent aneurysm or other potentially catastrophic failure, and demonstrated remodeling of the vessel wall after several weeks, to incorporate the magnets, making indefinite retention of field strength unnecessary. This technique could enable minimally invasive procedures, such as complex reconstructive and revascularizing surgery, and warrants further study in vessels with different sizes, flow rates, and locations.     

Microvascular thermic sleeve anastomosis: a sutureless technique

Microvascular thermic sleeve anastomosis performed with bipolar coagulation was investigated under experimental conditions. Patency rates of 100 percent for arteries (approximately 1.0 mm in external diameter) and 78 percent for veins (approximately 0.7 mm in external diameter) were achieved. The lumen contour was studied with plastic casts done at intervals of three hours, one day, three days, seven days, 15 days, and 30 days postoperative. Histopathologic studies were carried out to determine the changes caused by intussusception and heating spots.     

Coronary end-to-side sleeve anastomosis using adhesive in off-pump bypass grafting in the pig

BACKGROUND: In the exploration of facilitated coronary anastomosis strategies, we assessed a new octylcyanoacrylate adhesive in combination with a modified end-to-side sleeve anastomosis in off-pump bypass grafting in the pig. METHODS: Sleeve-adhesive anastomoses (n = 20) were evaluated intraoperatively, at 3 days (n = 4), and at 5 weeks (n = 16) in an off-pump, low (< or = 15 mL/min; n = 10) and high flow (approximately 60 mL/min; n = 10) porcine bypass model. All anastomoses were examined by flow measurement, angiography, and histology. RESULTS: Anastomosis construction took 8.5 minutes (6.7 to 10.2 minutes; median [15th to 85th percentile]). At 5 weeks, all anastomoses were fully patent (FitzGibbon grade A). The adhesive did not cause impaired vessel wall healing, but was surrounded by a focal acute and limited chronic (foreign body giant cells occasionally seen) inflammatory reaction at the adventitial application site. CONCLUSIONS: Octyl-cyanoacrylate tissue adhesive combined with end-to-side internal mammary to coronary artery sleeve anastomosis construction proved to be feasible, even in low bypass graft flow conditions (< or = 15 mL/min; prothrombotic milieu) in the pig and deserves interest in exploration of facilitated anastomosis strategies in coronary artery bypass grafting.     

A systematic review of sutureless vascular anastomosis technologies

Vascular anastomoses typically involve a handsewn technique requiring significant surgical training, expertise, and time. The aim of our systematic review was to identify and describe sutureless vascular anastomosis techniques. We performed a systematic review of all sutureless vascular anastomosis technologies published in MEDLINE, PubMed, Embase, CINAHL, Cochrane, Web of Science, and Scopus Library databases and a patent review using US Patent and Trade Office Application, US Patent and Trademark Office Patent, Google Patents, Lens, Patent Quality Through Artificial Intelligence, SureChEMBL, and E-Space Net. Data from inclusion studies and patents published between January 1, 1980 and July 15, 2021 were abstracted to describe their category, anastomosis type and configuration, study types, and advantages and disadvantages encountered with each technology. Two hundred eleven original studies and 475 patents describing sutureless vascular anastomosis technologies were identified. In the literature, stents/stent–grafts/grafts (n = 61), lasers (n = 53), and couplers (n = 27) were the predominant device categories. In the patent review, adhesive technologies (n = 103), stents/stent–grafts/grafts (n = 68), and mechanical connectors (n = 61) predominated. The majority of studies involved in vivo animal studies (n = 193); 32.2% (n = 68) of investigations involved human trials; and 17.9% (n = 85) of patent technologies were approved by the US Food and Drug Administration. The main advantages described for sutureless anastomosis technologies included faster procedure time and greater patency rates compared with handsewn anastomoses. The main disadvantages included reduced vessel compliance, stenosis, leakage, and device costs. The appeal of sutureless technology is substantiated by numerous animal trials, but their use in humans remains limited. This may be a reflection of strict regulatory criteria and/or vascular complications associated with currently available technologies.     

Microarterial sutureless sleeve anastomosis using a polymeric adhesive: an experimental study

A new technique for microarterial sutureless anastomosis that involves telescoping one vessel into the other and placing a microdrop of a polymeric adhesive (iso-propyl-cyanoacrylate) is described. Sixty-six anastomoses were performed in rat femoral arteries with a patency rate of 95 percent. Light and electron microscopic studies were conducted at regular intervals, starting immediately to 90 days postoperative. From this experimental study, it appears that the described method of anastomosis is faster and easier to perform and at least as reliable as the conventional end-to-end suture anastomosis. In addition, it was observed that tissue reaction to the glue remained primarily adventitial and did not disturb vessel patency.     

Coronary artery bypass grafting using side-to-side anastomosis

Recently, to obtain better long-term patency after coronary artery bypass grafting (CABG) arterial conduits such as internal mammary arteries (IMAs) and the right gastroepiploic artery have been frequently used. For coronary site anastomosis, end-to-side anastomosis is common. These conduits have a smaller diameter than the saphenous vein graft, so that, usually, longitudinal slits are made on the distal end of these grafts to obtain a more effective anastomotic orifice area. However, there is a potential for anastomotic leakage due to mismatch between the incision of the coronary artery and the arterial graft. We report here the efficacy of side-to-side anastomosis using small arterial conduits. This method has several advantages. Firstly, there is no chance of anastomotic leakage, since the coronary incision and graft incision can be perfectly matched. Secondly, if there is at least a 5-mm distance between the distal end of the graft incision and the surgical clip, the graft incision can be extended during anastomosis for adjustment. Thirdly, the distal end of the graft can be held beyond the surgical clip by forceps without damaging the arterial graft, which makes it easier for the anastomosis to be performed. Finally, the anastomosis can be checked by passing a probe through the distal end of the graft after removing the surgical clip. Also dye can be injected from the distal end of the graft at "Off Pump CABG", intraoperatively. This technique can be applied not only for distal end anastomosis, but also for proximal end, using free IMA to the ascending aorta and to make a Y-graft.     

Video-assisted replacement or bypass grafting of the descending thoracic aorta with a new sutureless vascular prosthesis: an experimental study.

PURPOSE: The feasibility of the video-assisted insertion of a new sutureless vascular prosthesis was studied. METHODS: Seven sheep, weighing 25 to 35 kg, were operated on under general anesthesia. The animals were intubated with a single-lumen endotracheal tube and placed in the right lateral decubitus position. A thoracoscope was introduced in the 11th intercostal space, and a minithoracotomy (4 to 5 cm) was performed in the seventh intercostal space. After retraction of the lung, a short segment (10 cm) of the descending thoracic aorta was exposed. Our prosthesis was made of Dacron and was specifically designed to be inserted without a suture. After systemic heparinization, the aorta was cross-clamped with two vascular clamps introduced into the thoracic cavity through two 5-mm thoracic incisions. The aorta was either replaced (five cases) or bypass grafted (two cases). At the completion of the procedure, blood pressure was pharmacologically increased (5 mg intravenous bolus of epinephrine), and each anastomosis was checked for bleeding. All animals were killed, and the prosthesis was retrieved for macroscopic examination. RESULTS: The procedure was completed in each case without extension of the minithoracotomy. Insertion of the prosthesis was easy and fast, and completion of each anastomosis required 10 to 15 minutes. A 3- to 4-mm space between each clip was sufficient for proper attachment. All procedures were performed in less than 120 minutes. No bleeding was observed at the level of each anastomosis, even when a sustained high blood pressure was induced. The proper insertion of the prosthesis and the absence of any anastomotic stenosis was confirmed by means of macroscopic examination. CONCLUSION: Video-thoracoscopic replacement or bypass grafting of the descending thoracic aorta was easy with this new sutureless vascular prosthesis. Minimally invasive vascular surgery might be facilitated with such a prosthesis. However, long-term animal studies are required before human implantation can be undertaken.     

Magnetic vascular coupling for distal anastomosis in coronary artery bypass grafting: a multicenter trial

OBJECTIVE: The hand-sewn anastomosis is the "gold standard" for performing coronary artery bypass grafts. However, performing a hand-sewn anastomosis is more demanding and time-consuming when used in less invasive approaches such as small access, totally endoscopic or beating heart surgery. In conjunction with attempts to reduce the surgical trauma of coronary artery bypass grafts by using these less invasive approaches, alternative methods for constructing distal anastomoses should be explored. These data report on predischarge angiographic findings and 30-day clinical follow up of patients who have received a new distal anastomotic device. METHODS: In a multicenter trial, 32 patients (mean age: 65 +/- 9 years; 85% men) requiring multivessel coronary artery bypass surgery had 1 of the anastomoses performed using a novel anastomotic technology. The Magnetic Vascular Positioner System was used in 1 of the bypass grafts and the other bypasses were completed by conventional hand-sewn technique. The Magnetic Vascular Positioner System consists of 4 magnetic, gold-plated implants and 2 delivery devices that facilitate the creation of a functional end-to-side anastomosis. A predischarge angiogram was performed to evaluate graft patency. RESULTS: There were no device-related major adverse events. The application of the Magnetic Vascular Positioner device was successful in 32 of 41 cases (78%). Nine patients were intended for treatment but did not receive the Magnetic Vascular Positioner System. In 5 of the cases the coronary artery was too small; 1 case had a posterior wall plaque in the target artery; and 3 patients had a nonhemostatic anastomosis after coupling of the port and were subsequently converted to hand-sewn anastomoses. The median total Magnetic Vascular Positioner anastomotic time was 137 seconds with a range from 65 to 370 seconds. Overall patency rate of the Magnetic Vascular Positioner anastomosis was 93.5% versus 91.7% (P = not significant) in hand-sewn grafts. One patient (3.1%) died due to low cardiac output but had patent grafts at autopsy. One myocardial infarction (3.1%) occurred the day after a percutaneous transluminal coronary angioplasty of a hand-sewn graft. One prolonged mechanical ventilation (3.1%) was required because of pneumonia and adult respiratory distress syndrome. CONCLUSIONS: Magnetic vascular coupling in coronary surgery is safe and effective and has acceptable early patency rates. This new technique may facilitate beating heart and minimally invasive coronary artery bypass grafts.     

Facilitated vascular anastomosis in coronary bypass surgery

The goal of truly minimally invasive surgical revascularization with 1-day hospital stays is shared by surgeons, patients, and payors alike. However, accomplishing this will involve doing surgery through more limited-access incisions and working within closed spaces. Suture management in this setting is cumbersome, slow, and unreliable. Facilitated anastomotic techniques and technologies are generally believed to be the vehicle that will ultimately allow us to address this. A considerable amount of time and resources has already been expended by many people and companies in this effort, with early clinical progress now being reported. Much more remains to be done, and other new approaches still need to be investigated. This article provides an overview or snapshot of the work and progress to date with facilitated vascular anastomoses along with some of the challenges that have yet to be solved. The achievement of a predictable, reproducible, and reliable technique to accomplish this will significantly and irrevocably reduce the extent of surgery required to revascularize the heart.     

Multivessel distal sutureless off-pump coronary artery bypass grafting procedure using magnetic connectors

Proximal anastomotic devices for beating heart coronary artery bypass grafting (CABG) have been developed to avoid ascending aortic manipulation. Distal anastomotic devices may become an extremely useful tool to assist in enabling minimally invasive (robotic) multivessel CABG. As a transition phase toward this ultimate goal we have been using a distal anastomotic device for the left internal mammary artery-left anterior descending artery (LIMA-LAD) anastomosis. In addition we recently performed two off-pump coronary artery bypass procedures that were distally completely sutureless.     

Evaluation of a poly(L-lactic acid) stent for sutureless vascular anastomosis

We have developed a sutureless anastomosis device consisting of a biodegradable stent and stainless steel band for end-to-end anastomosis. The aim of this acute phase study was to evaluate the feasibility of a sutureless anastomotic procedure with a bioabsorbable stent during a 4-week period in a swine model. The porcine infrarenal aorta was replaced with an expanded polytetrafluoroethylene graft. A proximal anastomosis was completed using a sutureless anastomotic procedure employing a bioabsorbable stent made of poly(L-lactic acid) (PLLA) and a stainless steel plate. A distal anastomosis completed by manual suturing served as a control. At 4 weeks after surgery, angiography was performed. The animals were then killed, and the specimens were evaluated histologically. The sutureless anastomotic procedure required significantly less time than the suturing technique. Angiograms showed patency of the grafts, and no signs of either stenosis or leakage. Both pressure-proof and tensile tests confirmed the adequate mechanical strength of the anastomoses. Sutureless anastomosis with a PLLA stent appears to be feasible, at least within an observation period of 4 weeks. This simple procedure shortened the time of surgery and would contribute to reducing the risks of operation-related complications.     

近端优先序贯技术在老年非体外冠状动脉循环旁路移植术中的应用

目的 探讨老年非体外冠状动脉旁路移植手术(OPCABG)中应用近端优先序贯技术的可行性及优越性.方法 2008年1月至2012年10月期间,72例65岁以上老年患者接受OPCABG手术,回顾性对比分析各项临床资料.患者分2组,近端优先序贯吻合组(序贯组)和常规吻合技术组(对照组).结果 序贯组患者心肌缺血(90.48±2.43) min,对照组(105.83±4.64) min,差异有统计学意义(P＜0.01).与对照组患者比较,序贯组ICU停留时间短(P＜0.05),术后输注红细胞量少(P＜0.05).两组间肌酸激酶同工酶(CK-MB)指标,术后24、72 h差异有统计学意义(P＜0.05).两组间肌钙蛋白I(TnI)术后6、24及72 h差异均有统计学意义(P＜0.05).结论 近端优先序贯技术较常规OPCABG技术对患者的心肌损伤小,是一种安全有效的手术方式.     

磁压榨吻合技术实现犬腹主动脉人工血管置换快速无缝线吻合

目的  探讨利用磁压榨吻合（MCA）技术实现犬腹主动脉人工血管置换快速无缝线吻合的可行性。方法  选择成年健康杂交犬12只,按腹主动脉与人工血管吻合方式分为MCA组和手工缝合（HS）组,每组6只。比较两组术中腹主动脉阻断时间、术中吻合口情况与术后吻合口影像学检查情况。结果  MCA组腹主动脉阻断时间短于HS组[（5.2±2.3）min比（24.4±4.3）min],差异有统计学意义（P < 0.001）。MCA组术中吻合口无渗漏血及狭窄情况发生;HS组术中6只犬均发生吻合口渗漏血,其中1只犬因失血过多死亡,2只犬因反复修补而出现吻合口轻度狭窄。MCA组术后彩色多普勒超声与血管造影检查显示吻合口血流通畅,无狭窄及血栓形成,HS组术后4周时血管造影检查共发现4只犬吻合口狭窄。结论  利用MCA技术可实现犬腹主动脉人工血管置换快速无缝线吻合,减少吻合口并发症的发生,有利于术后恢复。     

Advantages of side-to-side anastomosis in the assessment and revision of coronary artery bypass grafting

With the advent of drug eluting stents in percutaneous coronary intervention, required quality level of coronary artery bypass grafting (CABG) has been elevating. To obtain nearly perfect patency of bypass grafts, intraoperative assessment and repair of abnormal grafts are helpful. We report systematic revision and safe repair technique of arterial grafts in CABG. Side-to-side instead of commonly used end-to-side anastomosis of arterial grafts is the first step in this technique. When any abnormalities are noted in intraoperative flowmetry of a graft, the distal surgical clip is removed. Free flow of the graft is measured. A coronary probe is gently inserted into the graft and the coronary artery. Vasodilators can be injected into the graft if necessary. When direct revision of the anastomosis is indicated, the graft is cut longitudinally from the distal end up to just proximal to the anastomotic site. The shape of the anastomosis can be observed directly without removing sutures. When re-anastomosis is not indicated, the distal remnant graft tissue is folded back and utilized as a patch. Thus the graft can be easily closed without narrowing.