Search

Microanastomosis presents a challenge in neurosurgical procedures, requiring specialized skills. Regular practice outside the operating room is crucial. This study aims to provide a detailed description of the side-to-side anastomosis technique and analyze its advantages in preventing failures compared with other variations. We examined the technique, characteristics, and outcomes of side-to-side bypass procedures for complex aneurysms in the anterior cerebral artery territory at our institution over the past decade. We compared our technique with those described in the literature by other groups. The Far East Neurosurgical Institute (FENI) technique was used in 15 patients, with 17 side-to-side anastomoses performed. The average anastomosis time was 27.5 minutes, with 100% patency in follow-up. Our technique demonstrated safety and effectiveness in treating intracranial aneurysms, yielding satisfactory short- and long-term functionality outcomes. We highlight the importance of maintaining a curvilinear arteriotomy shape, at least 3 times the diameter of the artery, and utilizing an interrupted suturing technique on the anterior wall. This paper presents the first comprehensive description of the side-to-side anastomosis technique, supported with images and videos for training and replicability. Our technique enhances flow dynamics and reduces the risk of acute thrombus formation. Training in simulators and microsurgery practice centers outside the operating room is essential for acquiring and refining microsurgical skills. [ABSTRACT FROM AUTHOR]

Good visualization is a prerequisite for performing microvascular anastomosis. The most commonly used dye, methylene blue, has several limitations: it is washed off quickly and stains all the vessel layers. The objective of our study is to use 2 new novel dyes for improving visualization. After ethical committee approval, 2 Dyes (2% cresyl violet, 1% eosin) were studied in 3 groups, 20 rats in each group and 5 rats in the combined group. End-to-side anastomosis was performed in the classic fashion in 45 rats. After venotomy, the dye was applied to the raw surface of the vessels and subsequently, anastomosis was performed. The improvement in visualization was judged by 3 blinded experts and nonexperts in 4 groups on a scale of 1–10. Scores were statistically analyzed. After 2 weeks, animals were re-explored to check the delayed patency, and segments were harvested for histopathologic analysis. The immediate and delayed patency rates were 100% (45/45) and 97% (33/34), respectively. In statistical analysis, the combined group (P = 0.005)was judged statistically significant because of the contrast in color. All the layers were stained by both dyes, staining lasted until the end of the surgery. Visibility of the cut ends was better in cresyl violet. All histopathologic findings suggested normal changes at the anastomotic site. This study showed that the use of these 2 dyes was not only feasible but highly efficacious. Even though all the layers were stained by both the dyes, the visibility of the cut ends was better. In both dyes, staining lasted until the end of surgery. To the best of our knowledge, this is the first study that has used these 2 novel dyes to improve visualization in microvascular anastomosis in an experimental setting. [ABSTRACT FROM AUTHOR]

A narrow working space, small diameters, and the tendency to collapse with clamps make cerebral microvascular anastomosis challenging. A retraction suture (RS) is a novel technique to keep the recipient vessel lumen open during the bypass. To provide a step-by-step overview of RS for end-to-side (ES) microvascular anastomosis on rat femoral vessels and successful use for superficial temporal artery to middle cerebral artery (STA-MCA) bypass in Moyamoya disease patients. A prospective experimental study with approval from the Institutional Animal Ethics Committee. Femoral vessels ES anastomoses were performed on Sprague Daley rats. The rat model used 3 types of RS (adventitial, luminal, and flap RSs). An ES-interrupted anastomosis was done. The rats were observed for an average period of 16.18 ± 5.65 days; the patency was assessed by reexploration. The immediate patency on the STA-MCA bypasses was confirmed with intraoperative indocyanine green angiography and micro-Doppler; delayed patency with magnetic resonance imaging and digital subtraction angiography after 3–6 months. In the rat model, 45 anastomoses were performed, 15 each using the 3 subtypes. The immediate patency was 100%. Delayed patency was 42/43 (97.67%), and 2 rats died during observation. In the clinical series, 59 STA-MCA bypasses were done in 44 patients (average age, 18.14 ± 11.09 years) using RS. The follow-up imaging was available for 41/59 patients. Both immediate patency and delayed patency (41/41 at 6 months) were 100%. The RS allows continuous visualization of the vessel lumen, reduces the handling of intimal edges, and avoids incorporating the back wall in sutures, thus improving anastomosis patency. [ABSTRACT FROM AUTHOR]

The use of the classic 2-ends anchoring technique is common in end-to side (ES) microvascular anastomosis. The literature on the toe-first (TF) technique is limited. In the current study we present the successful outcomes with the TF technique in ES anastomoses in rat femoral vessels model. ES microvascular anastomosis with the tf technique was performed in the femoral vessels of 10 Sprague Dawley rats. Two-throw reef knot interrupted sutures were used in all cases. Individual parameters during the procedure were recorded for analysis. The immediate and delayed (cut open technique after 2 weeks) patencies were confirmed. An illustrative case showing the use of this technique in superficial temporal artery to middle cerebral artery bypass in a pediatric moyamoya disease case is included. The average suturing time was 40.14 ± 5.30 minutes, the procedures were completed with an average of 14.57 ± 1.90 sutures. The average time per suture was 2.78 ± 0.43 minutes. The immediate patency was 100% (10 of 10 cases). Two rats died of unknown cause in the observation period. The delayed patency was 100% in the remaining 8 cases (average observation: 29.6 days). The TF interrupted suture technique of ES microvascular anastomosis with 2-throw reef knots is feasible with excellent immediate and delayed patency rates. The distinct advantages of the TF are the continuous visualization of the recipient lumen during anastomoses, avoiding back-wall bites, and the ability to correct any discrepancy in the recipient–donor lumens during the procedure. [ABSTRACT FROM AUTHOR]

The use of a 3-throw knot for anastomosis by microvascular neurosurgeons is the usual standard. There is an inherent belief that the third throw adds extra security to the knot; however, the third throw can make the knot heavy and unbalanced and can exert undue extra pressure on the opposing walls of the small-caliber intracranial vessels. This study evaluated the feasibility and efficiency of 2-throw reef knot interrupted sutures for an end-to-side microvascular anastomosis. A prospective observational study of end-to-side anastomosis using a femoral artery–to–vein model was performed in 30 Sprague–Dawley rats. All anastomoses were done using 2-throw reef knot interrupted sutures. Ten procedures each were done by the heel-first, toe-first, and classic 2-ends techniques. Individual parameters were recorded for analysis. The delayed patency was confirmed by reexploration after a mean duration of 19.82 ± 8.12 days. The overall patency rates were 100% in the immediate period and 96.43% (27 of 28) in the delayed period. The average clamping time, average suturing time, and the average time per suture were 65.48 ± 16.93 minutes, 40.94 ± 11.22 minutes, and 3.18 ± 1.10 minutes, respectively. Two rats died in the postoperative period. The end-to-side microvascular anastomosis with 2-throw reef knots is feasible, with excellent immediate and delayed patency rates. [ABSTRACT FROM AUTHOR]

Laboratory training is a very important step on the development of the skills necessary for a neurosurgeon. This can be achieved using animal models and surgical microscopes or stereomicroscopes. Methods, like the use of fluorescein, increase the lifelike situation and allow anyone to assess the patency of an anastomosis and improve the quality of this training. We report the use of a stereomicroscope with white light and a fluorescence mode used to perform dissection of small arteries and anastomosis using a chicken wing model. Using an affordable device, we could perform fluorescein videoangiography to asses the patency of those anastomosis and improve the quality of the training skills in microsurgery. The stereomicroscope is a useful tool for laboratory training and can be used as a substitute of a surgical microscope for microsurgery training. The fluorescence mode allowed us to perform fluorescein videoangiography with very a good quality of image. Microsurgery training is important part in the life of any neurosurgeon. Using a stereomicroscope with a fluorescence mode is an affordable method that can be reproduced in any laboratory in the world. [ABSTRACT FROM AUTHOR]

Microscopic training is essential for development of neurosurgical skills. A range of models is reported in the literature for this purpose, including live animals, exvivo, and synthetic material. Among the factors involved in selection and development of a training station, cost is a decisive one. We present a low-cost model to practice microvascular anastomoses using a bovine heart and an artificial perfusion system. We also present a brief review of laboratory models for microsurgical training, focusing on the costs and reproducibility of the different options. Exvivo models are a great bridging point between nonbiologic and living animal training models. These models have major similarities to human vessels, such as lumen size and malleability of the arteries. The bovine heart model allowed the residents to gain confidence in handling vascular tissue in a microscopic environment. Although these models do not resemble anatomic landmarks in the human brain, the bovine heart model allowed the residents to gain confidence in handling vascular tissue in a microscopic environment. [ABSTRACT FROM AUTHOR]

Background Neurovascular training models include animal models, synthetics, or computer simulation. In vivo models are expensive and require significant resources. Synthetic/computer models do not reflect the elasticity of fresh vessels. We describe an endovascular and microsurgical training model using a chicken thigh/leg. Methods A total of 20 chicken thigh/leg models were obtained. Angiography was used to understand the anatomy. Proximal cannulation with a 5-French catheter was achieved and connected to a hemostatic valve with a pump to simulate pulsatile flow. Aneurysms were created at the thigh-leg junction. For clipping training, 3 types of aneurysms were created to reproduce anatomy seen in middle cerebral, anterior communicating, and posterior communicating aneurysms. Results The average cost per specimen was $1.70 ± $0.30. The diameter of the proximal femoral artery was 2.4 mm ± 0.2 mm. The length from the proximal femoral artery to the aneurysm was 9.5 cm ± 0.7 cm. Distal catheterization was successful in all cases (n = 6). Successful deployment of coils and a stent was achieved under fluoroscopic guidance. Gross oversizing of coils and other mistakes led to aneurysm rupture. Each examiner performed an exploration of the pulsatile aneurysm, application and reapplication of a variety of clips, and then the final inspection of branching vessels to confirm patency. Conclusions The chicken thigh/leg model provides training opportunities in microsurgical suturing, endovascular techniques for aneurysm obliteration, and microsurgical reconstruction of aneurysms. It combines affordability, time efficiency, and reproducibility. Further studies measuring improvement in technical aneurysm management and comparison with other training models are warranted. [ABSTRACT FROM AUTHOR]

Background Microvascular anastomosis is an essential procedure in neurosurgery, but the opportunity to perform the surgery has gradually decreased for neurosurgeons. Therefore, training is necessary for obtaining and maintaining the skills required for the procedure. We describe the detailed anatomy of cervical and femoral regions in rats and discuss the advantages for practicing microvascular anastomosis. Methods Cervical regions of Sprague-Dawley rats were dissected under intraperitoneal anesthesia. The step-by-step anatomic description was documented using a high-resolution charge-coupled device image sensor and recording systems. Using this model, temporal occlusion time and patency were measured, and these measures were compared between the trainee and trainer groups. The number of times the training needs to be completed to attain competency in the bypass procedure was estimated. Results After exposing the carotid triangle, a half-ring was created by end-to-side anastomosis. Anastomosis was performed at the common carotid artery using the contralateral side of the carotid artery as a graft. The cutoff value for the temporal occlusion time was 79.3 minutes in the receiver operating characteristic curve based on a target temporal occlusion time for beginners determined during the training. Conclusions Using a living animal model, a trainee has the opportunity to learn not only anastomotic techniques but also hemostatic control as well as overcoming mental strain during surgery. Living animal models are important in training because the fidelity of a living animal model is superior to nonliving models. Applying training using a half-ring model contributes to safe and efficient surgery. Highlights • Living rat models provide an opportunity to learn dissection and anastomosis. • We present anatomy and dissection and anastomosis techniques using the cervical region. • High-resolution photographs, drawings, and videos are provided to illustrate techniques. • The number of times the training needs to be completed to attain competency was estimated. [ABSTRACT FROM AUTHOR]

Background The end-to-side anastomosis is 1 of the most common anastomosis configurations used in cerebrovascular surgery. Although several living practice models have been proposed for this technique, few involve purely arterial vessels. The purpose of the present study was to compare 2 arterial models using common carotid arteries (CCAs) and common iliac arteries (CIAs) in rats. Methods The CIAs and CCAs were exposed in 10 anesthetized rats, and their lengths and diameters were measured. Also, the mobilization extent of each vessel along its contralateral counterpart was measured after each artery had been transected at its proximal exposure point. We also studied the technical advantages and disadvantages of each model for practicing end-to-side anastomosis. Results The average diameters of the CCA and CIA were 1.1 and 1.3 mm, respectively. The average extent of mobilization along the contralateral vessel was 13.9 mm and 10.3 mm for CCA and CIA, respectively. The CCA model had the advantages of greater arterial redundancy (allowing completion of both suture lines extraluminally) and a minimal risk of venous injury. The main disadvantage of the CCA model was the risk of cerebral ischemia. The CIA model was not limited by the ischemic time and provided the technical challenge of microsurgical dissection of the common iliac vein from the CIA, although it had limited CIA redundancy. Conclusions Both CCA and CIA models could be efficiently used for practicing the end-to-side anastomosis technique. Each model provides the trainee with a specific set of advantages and disadvantages that could help with the optimal selection of the practice model according to trainee's skill level. Highlights • End-to-side anastomosis is a common bypass procedure in neurosurgery. • The training models for the end-to-side anastomosis have not been optimized. • We compared the rat carotid and iliac arteries as models for practicing end-to-side anastomosis. • The carotid model was more robust in vessel mobilization and ease of dissection. • The iliac model offered the advantage of theoretically limitless ischemia time. [ABSTRACT FROM AUTHOR]

Objective To study the rate of superficial temporal artery (STA) preservation and the effectiveness of STA reconstruction in patients undergoing a pterional craniotomy. Methods Included patients ( n = 136) underwent either an emergency or an elective pterional craniotomy. In case of deliberate transection or accidental damage of the STA, it was repaired microsurgically at the end of the procedure. Postoperatively, the patency of the STA was assessed on CT angiography, MR angiography, or conventional angiography and complications related to wound healing were recorded. Results Of the 136 operated patients, the STA could be identified in 120 cases (88%). Of these 120 cases, the STA could be dissected and left undamaged in 60 patients (44%). In 52 patients (38%), 1 of the 2 branches of the STA had to be transsected to elevate the muscle-skin flap. Forty-six of the transected arteries could be anastomosed at the end of the procedure. All of these arteries were patent directly after repair. In the remaining 16 patients (12%), the STA was not identified during approach. All anastomosed arteries ( n = 46) were patent. Two patients developed a postoperative infection. Conclusions Preserving or reconstructing of the STA during pterional craniotomy is feasible in the majority of the patients with very high rate of anastomosis patency. STA hinders elevation of the skin/muscle flap in approximately 38% of the pterional approaches and without reconstruction afterwards, the STA would been occluded. [ABSTRACT FROM AUTHOR]