Sutureless Microvascular Anastomosis Research Articles

Sutureless venous microanastomosis using thermosensitive poloxamer and cyanoacrylate: experimental study on a rat model

Sutureless microvascular anastomoses could simplify the microvascular field, shortening operative time and improving the final outcome. The use of thermosensitive poloxamers (TP407) together with the application of cyanoacrylate as an alternative method for conventional sutures was well-documented for arteries, but not for veins. The purpose of our study was to prove the feasibility of this technique for venous anastomoses and compare it with the traditional hand-sewn technique on a rat model. Twenty male Sprague-Dawley rats that weighed between 265 and 310g were used. In the sutureless group (SG), 20 left external jugular veins (LEJV) end-to-end anastomoses were performed using a T704 and cyanoacrylate glue. They were compared to 20 right external jugular veins (REJV) anastomoses sutured with conventional 10-0 stitches (control group - CG). Diameters of veins, anastomosis time, and patency rate at 15 days were reported. Foreign body reaction was assessed histologically. The mean diameter of the LEJV was 0.94±0.1mm and 0.95±0.09mm for the REJV. The mean anastomosis time was 11.9±1.37min for the SG and 27.75±3.31min for the CG. In the latter group, the immediate patency rate was 95% and 90% at 15 days. For the SG group, 90% of the anastomoses were patent immediately and 85% at 15 days. TP407 and cyanoacrylate could offer a fast and reliable technique for sutureless venous anastomoses. Before human application, effectiveness of this method remains to be confirmed in larger animals in a long-term follow-up.

Sutureless Microvascular Anastomosis: Literature Review

Traditionally, suturing techniques have been the mainstay for microvascular anastomoses, but owing to its technical difficulty and labour intensity, considerable work has gone into the development of sutureless microvascular anastomoses. In this review, the authors take a brief look at the developments of this technology through the years, with a focus on the more recent developments of laser-assisted vascular anastomoses, the unilink system, vascular closure staples, tissue adhesives, and magnets. Their working principles, with what has been found concerning their advantages and disadvantages are discussed.

Sutureless Microvascular Anastomosis using Intravascular Stenting and Cyanoacrylate Adhesive.

Microvascular anastomosis using cyanoacrylate adhesive has a reputation among researchers as an alternative to conventional sutures. However, a degree of ingenuity is required to avoid the collapse of the vascular lumen for the duration of the anastomosis. The aim of this study was to determine the feasibility of intravascular stenting (IVaS) as a temporary stent during sutureless microvascular anastomosis with cyanoacrylate adhesive. Sixty male Fisher 344 rats were evenly divided into two groups. The right superficial femoral arteries (RSFAs) were transected in each group. Microvascular anastomoses were then performed with the sutureless (SL) method in one group and conventional sutures (CS) in the other group. The diameter of the RSFA, duration of microvascular anastomosis, and the patency of the RSFA were evaluated immediately after anastomosis and 7 days after the surgery. Tissue samples were obtained for pathological consideration. There was no significant difference in the diameter of the RSFAs between the SL and the CS groups. There was no significant difference in the patency rates of the groups. The anastomosis time of the SL group was significantly shorter than that of the CS group, regardless of the experience of the surgeons. A histological analysis showed a comparable level of foreign body reactions in each group. IVaS plays a supportive role in sutureless microvascular anastomosis with cyanoacrylate adhesive. The short-term safety of this technique has now been confirmed at the experimental stage.

Sutureless microvascular anastomosis assisted by an expandable shape-memory alloy stent.

Vascular anastomosis is the highlight of cardiovascular, transplant, and reconstructive surgery, which has long been performed by hand using a needle and suture. However, anastomotic thrombosis occurs in approximately 0.5–10% of cases, which can cause serious complications. To improve the surgical outcomes, attempts to develop devices for vascular anastomosis have been made, but they have had limitations in handling, cost, patency rate, and strength at the anastomotic site. Recently, indwelling metal stents have been greatly improved with precise laser metalwork through programming technology. In the present study, we designed a bare metal stent, Microstent, that was constructed by laser machining of a shape-memory alloy, NiTi. An end-to-end microvascular anastomosis was performed in SD rats by placing the Microstent at the anastomotic site and gluing the junction. The operation time for the anastomosis was significantly shortened using Microstent. Thrombus formation, patency rate, and blood vessel strength in the Microstent anastomosis were superior or comparable to hand-sewn anastomosis. The results demonstrated the safety and effectiveness, as well as the operability, of the new method, suggesting its great benefit for surgeons by simplifying the technique for microvascular anastomosis.

Sutureless microvascular anastomosis with the aid of heparin loaded poloxamer 407

Anastomosis with tissue adhesives is an alternative method for conventional anastomosis. However, this method has several technical challenges. It requires the use of suture to prevent leakage into lumen and precise application onto all surfaces of the anastomosis site. To solve these problems, poloxamer 407 (P 407) was previously used as a stent. In this study, we made heparinized P 407 (h-P 407) as a new formula. We aimed to successfully use h-P 407 as a stent in sutureless anastomosis in a rat abdominal aorta model. Sixty Sprague-Dawley rats were used. In the first group, end-to-end anastomoses were performed with suture; in the second and third groups, sutureless anastomoses were performed with 2-octyl cyanoacrylate. As an intraluminal stent, P 407 was used in the second group, and h-P 407 was used in the third group. Anastomosis time was measured. Lumen width, intimal hyperplasia, and foreign body reaction were assessed histologically. Velocity flow rates and vessel diameters were measured radiologically. Burst strength was measured, and the results were statistically evaluated. Sutureless anastomosis was more rapid than conventional anastomosis. Lumen width was narrower in the suture group. İnflammation and foreign body reaction were more severe in the suture group. There was no radiologic and biomechanical difference between the groups. We found that intimal hyperplasia was less in h-P 407 than in P 407. h-P407 can be successfully used as an intraluminal stent for sutureless microvascular anastomosis with tissue adhesives.

Sutureless Microsurgical Anastomosis Using an Optimized Thermoreversible Intravascular Poloxamer Stent

Sutureless microvascular anastomosis has great translational potential to simplify microvascular surgery, shorten operative times, and improve clinical outcomes. The authors developed a transient thermoreversible microvascular stent using a poloxamer to maintain vessel lumen patency before application of commercially available adhesives to seal the anastomosis instead of sutures. Despite technical success, human application necessitates bovine serum albumin removal from existing formulations; rapid poloxamer transition between states; and increased stiffness for reliable, reproducible, and precise microvascular approximation. Two commercially available poloxamers were used in this study (P407 and P188). After removing bovine serum albumin, each poloxamer was tested at varying concentrations either alone or in combination to determine the optimal preparation for sutureless microvascular anastomosis. Transition temperature and formulation stiffness were tested in vitro by rheometry, with the most promising combinations tested in an established in vivo model. Increasing poloxamer concentration resulted in an increase in stiffness and decrease in transition temperature. Pure P188 without bovine serum albumin, dissolved in phosphate-buffered saline to a 45% concentration, demonstrated desirable rheologic behavior, with precise gel transition and increased gel stiffness compared with our previous formulation of 17% P407 (96 kPa versus 10 kPa). These characteristics were optimal for microsurgical intravascular use, offering surgical precision and control between liquid and solid states, depending on the surgically controlled local temperature. Use of 45% P188 without bovine serum albumin demonstrated optimal rheologic and translational properties as a microvascular stent for sutureless anastomosis. Rapid transition, increased stiffness, and safety profile demonstrate safe translational application for human clinical trials.

A photochemical tissue bonding approach for rapid sutureless microvascular anastomosis with minimal inflammation in an arterial graft model

A photochemical tissue bonding approach for rapid sutureless microvascular anastomosis with minimal inflammation in an arterial graft model

Technology-assisted and sutureless microvascular anastomoses: evidence for current techniques

Technology-assisted and sutureless microvascular anastomoses: evidence for current techniques

Use of a Novel Penetrating, Sutureless Anastomotic Device in Arterial Microvascular Anastomoses

The advent of microsurgery and microvascular anastomosis has helped to alter the treatment of many traumatic defects as well as revolutionize the reconstructive options after extirpative surgery. These procedures, however, continue to be technically demanding and intensive. In addition, increased ischemia and operative times are known to raise complications in microsurgery, particularly in older patients. The nitinol U-clip (Medtronic, Inc., Minneapolis, MN) is a new penetrating clip applied in an interrupted fashion that eliminates knot tying and decreases operative time. This technology holds the potential for rapid, reproducible sutureless microvascular anastomoses. In addition, the surgical technique is very similar to conventional suture microanastomosis, lending itself to comparatively decreased learning curves and suitability for training programs. We present three consecutive cases of successful microsurgical anastomoses using this technology.

LESSONS LEARNED FROM LASER TISSUE SOLDERING AND FIBRIN GLUE PYELOPLASTY IN AN IN VIVO PORCINE MODEL

LESSONS LEARNED FROM LASER TISSUE SOLDERING AND FIBRIN GLUE PYELOPLASTY IN AN IN VIVO PORCINE MODEL

Microvascular Anastomosis Using 2-Octyl Cyanoacrylate in the Rat Femoral Artery

Patency of the microvascular anastomosis is the most important requirement for tissue survival in free tissue transfer and in replantation. In efforts to improve on the standard suture method of microvascular anastomosis, new techniques such as limited-suture sleeve anastomoses and histoacryl glue anastomoses have been employed experimentally. However, as a result of factors such as tissue toxicity and suboptimal outcome, cyanoacrylates have not enjoyed clinical use. In addition, sleeve anastomoses continue to utilize suture, increasing the risks of intimal damage, platelet adhesion, and thrombosis. In an attempt to surmount these problems, the authors investigated the use of a new 2-octyl cyanoacrylate glue and a sutureless sleeve anastomosis. Anastomosis of 20 rat femoral arteries with a sutureless sleeve technique bonded with glue resulted in an 80% patency rate at 1 day to 3 weeks. Failures occurred in the first few attempts as the technique was evolving. These encouraging results suggest that 2-octyl cyanoacrylate may have applicability in quick, sutureless microvascular anastomoses.

Alternative wavelengths for sutureless laser microvascular anastomosis: a preliminary study on acute samples.

Attempts to improve the speed and patency of microvascular anastomosis with laser-assisted techniques have provided a modest reduction in operative time and comparable success rates. Using sutureless microvascular anastomoses, 30 end-to-end anastomoses were created in the rat carotid artery using the gallium-aluminum-arsenide diode laser (808 nm). Indocyanine green and fibrinogen were applied to enhance tissue absorption of the laser energy and strengthen the bond created. These were compared with previously reported welds using the THC:YAG laser (2150 nm). Mean welding times were 140 and 288 s, and mean bursting pressures immediately after welding were 515 and 400 mmHg for the diode and THC:YAG laser groups, respectively. Histologically, both lateral and vertical spread of thermal damage was limited. Since both lasers create welds of adequate initial strength without stay sutures and are faster and easier to use than existing systems, evaluation of long-term patency would be worthwhile.

Sutureless microvascular anastomosis using the THC:YAG laser: a preliminary report.

Laser anastomosis of the rat carotid artery was performed using a new mid-infrared laser, the pulsed thulium-holmium-chromium: YAG (THC:YAG) laser (2.15 microns). Solid silicone stents made stay sutures unnecessary for coaptation of vessel edges during laser bonding. Grossly, the laser anastomoses displayed minimal thermal distortion of the vessel contour and no tissue carbonization. Of the 30 anastomoses performed, 27 were patent and 3 had separation of the weld shortly after the approximator clamp was released. Mean anastomotic time was 4 min 48 sec. Mean bursting pressure for the 9 vessels tested was 400 mm Hg. Thrombosis did not occur at any time during our examination of these anastomoses. Fusion of collagen fibers in the media was confirmed histologically. Unlike the CO2 laser, the THC:YAG is transmissible through flexible silica fibers, which greatly facilitates delivery of the laser in a microsurgical operative field. The THC:YAG provides shallower absorption depth than Nd:YAG and argon lasers but somewhat deeper tissue penetration than CO2. For microvessels, this intermediate absorption results in full-thickness fusion of the media, with minimal thermal damage to vascular tissue adjacent to the anastomosis.

Nd-YAGレーザーを用いた無縫合微小血管吻合の試み

Nd-YAGレーザーを用いた無縫合微小血管吻合の試み