Microsurgical Vascular Anastomosis Research Articles

Extended autologous tracheal replacement by a novel pedicled thoraco-chondro-costal flap: a cadaveric proof of concept.

Our aim was to report an anatomic model of an autologous flap based on the internal thoracic blood supply: the pedicled thoraco-chondro-costal flap; and establish the feasibility of various types of extended tracheal replacement with this novel flap, according to a newly proposed topographic classification. In a cadaveric model, a cervicotomy combined with median sternotomy was performed. The incision was extended laterally to expose the chest wall. The internal thoracic pedicle was freed from its origin down to the upper limit of the delineated flap to be elevated. The perichondria and adjacent periostea were incised longitudinally to remove cartilages and adjacent rib segments, preserving perichondria and periostea. A full-thickness quadrangular chest wall flap pedicled on internal thoracic vessels was then elevated and shaped into a neo conduit to replace the trachea with the pleura as an inner lining. Various types of extended non-circumferential and full-circumferential tracheal replacements were achieved with this composite flap. No anastomosis tension was noticed despite the absence of release manoeuvres. This model could represent a suitable autologous tracheal substitute, which is long, longitudinally flexible and eventually transversely rigid. No microsurgical vascular anastomoses are required. The technique is reproducible. The perichondria and periostea would regenerate vascularized neo-cartilaginous rings, potentially decreasing the need for long-term stenting. The inner pleural lining could potentially transform into ciliated epithelium as shown in previous preclinical studies.

Effect of Sleep Deprivation on Simulated Microsurgical Vascular Anastomosis.

The effects of sleep deprivation on surgical performance have been well documented. However, reports on the effects of sleep deprivation on microneurosurgery are limited. This study aimed to investigate the effects of sleep deprivation on microneurosurgery. Ten neurosurgeons participated in the anastomosis of a vessel model using a microscope in sleep-deprived and normal states. We evaluated the procedure time (PT), stitch time (ST), interval time (IT), number of unachieved movements (NUM), leak rate, and practical scale for anastomosis quality assessment. Each parameter was compared between normal and sleep-deprived states. Subanalyses were performed on the two groups based on PT and NUM under the normal state (proficient and nonproficient groups). Although no significant differences were noted in PT, ST, NUM, leak rate, or practical scale, IT was significantly prolonged under sleep deprivation compared with the normal state (mean: 258.8 ± 94.0 vs. 199.3 ± 74.9 seconds; p = 0.02). IT was significantly prolonged under sleep deprivation in the nonproficient group based on both PT and NUM (PT: 234.2 ± 71.6 vs. 321.2 ± 44.7 seconds, p = 0.04; NUM: 173.3 ± 73.6 vs. 218.7 ± 97.7; p = 0.02), whereas no significant difference was observed in the proficient group (PT: 147.0 ± 47.0 vs. 165.3 ± 61.1 seconds, p = 0.25; NUM: 173.3 ± 73.6 vs. 218.7 ± 97.7; p = 0.25). Although IT was significantly prolonged under sleep deprivation in the nonproficient group, there was no decline in performance skills in either the proficient or nonproficient group. The effect of sleep deprivation may require caution in the nonproficient group, but it is possible that certain microneurosurgical outcomes can be achieved under sleep deprivation.

Applying the Microvascular Anastomotic Coupler Device to End-to-side Venous Anastomosis in Reconstructive Surgery

Background:Microsurgical vascular anastomosis plays an important role in successful free-tissue transfer. The Microvascular Anastomotic Coupler Device (MACD) aims to simplify anastomosis and decrease the time spent on this step, thereby reducing surgeon stress and improving the overall quality of the surgery, especially when venous end-to-side anastomosis is required. Our comparative retrospective cohort study aimed to determine the effect of this widely used device on anastomosis times and complications in head and neck/esophageal reconstruction cases involving venous end-to-side anastomosis using the internal jugular vein as the recipient vessel.Methods:All consecutive patients who underwent head and neck/esophageal reconstruction with hand-sewn or MACD-mediated venous end-to-side anastomosis using the internal jugular vein by three experienced microsurgeons in our tertiary-care hospital in 2012–2020 were identified. Venous anastomosis times and venous trouble cases were recorded.Results:Of the 191 cases, 44 and 147 underwent hand-sewn and MACD-mediated anastomosis respectively. The average venous anastomosis times of these groups were 31 and 11 minutes, respectively. Venous trouble was observed in two hand-sewn (4.5%) and four MACD (2.7%) cases, respectively. Vein twisting and improper coupler placement were the causes in the latter four cases.Conclusions:This study confirmed that MACD simplifies end-to-side venous anastomosis and reduces the time spent on this procedure. Also, for safer anastomosis, it is necessary to pay attention to preventing twisting and improper coupler placement when using MACD. We believe the MACD can improve the quality of reconstructive surgery.

Learning microvascular anastomosis: Analysis of practice patterns

BackgroundPerforming a successful microsurgical vascular anastomosis (MVA) is challenging and requires lots of practice. However, the most efficient practice protocol is yet to be found. We aimed to compare and analyze two major practice patterns for fine motor tasks as applied to learning MVA: distributed and mass practice protocols. Ten neurosurgeons with comparable experience in microsurgery (but no experience in vascular anastomosis) were randomized to practice MVA either using a distributed (1 session/day) or a mass practice (6 sessions/day) protocol. A total of 24 sessions of practice and 2 recall test sessions were given. Anastomosis score, time to complete a single stitch and the total time to complete an anastomosis were recorded. Mass practice protocol caused a clear fatigue effect observed toward the end of each mass practice trial block. Statistical comparison using one-way analysis of variance showed significantly higher anastomosis scores and shorter times to place a single stitch as well as to complete the anastomosis in distributed practice group for the last 3 acquisition practice trials, and the 2 recall tests (p < 0.05). The relative advantage of the distributed practice protocol could be attributed to forgetting/spacing effect. Although mass practice protocol resulted in worse performance, it still showed a gradual improvement trend in performance from beginning to the end. Therefore, certain adjustments to a mass practice protocol (such as increasing the number of practice blocks) could potentially lead to an eventual performance level comparable to a distributed protocol. This point is a subject of further investigation.

VITOM® 3D in Arterio-Venous Fistulas: Single Centre Preliminary Surgical Experience

Background: Arteriovenous fistula (AVF) is the vascular access of choice for hemodialysis patients. A correct microsurgical vascular anastomoses is essential to the optimal care of patients. Loupes can help surgeons perform such procedures, but often cause neck or back pain and fatigue. Aim: This study aimed to evaluate whether a video telescopic operating microscope (VITOM®; Karl Storz Endoscopy GmbH, Tuttlingen, Germany) could be used as a substitute for loupes to create microsurgical vascular anastomoses. Methods: We evaluated microsurgical anastomoses with VITOM® in 10 patients (6 male, 4 female) from January 2019 to December 2019. The created anastomoses were 7 side-to-side, 2 side-to-end and 1 end-to-end. Results: A valid thrill was always present on palpation. Surgical procedures had an average time of 87.6 min, ranging from 49 to 110 min. Eight patients had AVF maturation; in the remaining 2, one had a thrombosis after 25 days and one couldn’t be dialyzed due to low flow in AVF. Conclusions: The VITOM® system makes it possible to carry out anastomosis in difficult cases. It is both safe and useful for the training of young surgeons.

VS-1-7 Female-to-Male Gender Affirming Surgery: The Pedicled Pubic Phalloplasty and Radial Artery Free-Flap Urethroplasty

The goal of genital female-to-male (FTM) gender affirming surgery is to create an aesthetically acceptable phallus to allow voiding while standing and penetrative sexual intercourse. The radial artery free flap phalloplasty accomplishes these goals but results in significant donor site scarring. The visible scarring can be minimised by incorporating a radial artery free flap urethroplasty inside a previously formed pedicled pubic phalloplasty. This technique combines the less technically challenging phalloplasty with a well-vascularised and stable urethra for voiding. The combined procedure is performed in 4 stages: 1) phallus formation 2) creation of neourethra by free flap microvascular transfer to the recipient site 3) laparoscopic hysterectectomy and bilateral salphingo-oopherectomy, vaginectomy, join-up urethroplasty, burying of clitoris, scrotoplasty and glansplasty 4) penile and testicular prosthesis insertion. Each stage is performed at 6-monthly intervals. Steps: 1) a 13cm by 14cm pedicled pubic flap is raised preserving the superficial epigastric vessels. 2) a 4cm x 17cm free flap neourethra based on the radial artery is raised from the relatively hairless medial forearm and tubularised. A disc of skin is excised at the phallus tip and space dilated to size 20 Hegar. The neourethra is tunnelled through the phallus and a spatulated urethral anastomosis is performed followed by microsurgical vascular and neural anastomoses. The donor forearm is resurfaced with a split thickness skin graft. 3) Modified Norfolk technique glansplasty with urethral lengthening using inner labial and anterior vaginal flaps. 4) Penile prosthesis prepared with polyethylene terephthalate cap and sock and testicular prosthesis inserted via separate groin incisions with placement of the reservoir in an extraperitoneal position.

Rat Model for Practicing Microsurgical Vascular Anastomosis.

Rat Model for Practicing Microsurgical Vascular Anastomosis.

Microsurgery Techniques for Patients with Traumatic Thumb Amputation

Introduction. Traumatic amputations of a thumb may happen as a result of severe mechanical injuries with the primary detachment and destruction of tissues, or following deep burns, frostbites or ischemia. In 70 to 80% of cases of disability and the loss of occupational fitness the key causes are traumatic digit and hand amputations. In 50% of cases the loss of ability to work is due to an amputation of a thumb. This makes the issue of thumb reconstruction a priority in surgery of the hand.Materials and methods. This paper presents our experience in the reconstruction of the functional abilities of the hand in 48 patients with traumatic amputations of a thumb. This was performed with the use of reconstructive plastic microsurgery techniques, namely the free transplantation of a second toe onto the hand. All the patients had a thumb stump at the level of the distal part of the metacarpal bone or the proximal part of the proximal phalanx.Results and discussion. A positive outcome was achieved in 45 out of the 48 patients treated. Autograft necrosis occurred in three cases. For these patients the thumb reconstruction was performed with the use of other, less functional methods. The functional condition of the hand manifested an improvement according to the electromyography data obtained at the maximum tonic tension of the thenar eminence muscles, flexor and extensor muscles of the reconstructed digit. In all the cases the hand strength increased by 40 to 90% after the reconstructive surgery; the authors attribute this to the recovery of the key handgrip abilities. According to Doppler ultrasonography data the blood flow velocity and the level of blood filling increased in the hand treated.Conclusion. The reconstruction of functional abilities of the hand with traumatic thumb amputation must be carried out taking into account the available methods of surgical correction and which one of these would be optimal, the evaluation of the patient’s mental status and his or her drive for the fastest possible recovery of the shape and function of the hand. The free autograft of a second toe in place of the lost thumb with microsurgical vascular anastomoses makes it possible to restore most completely the aesthetic and functional abilities of the hand in the shortest possible timeframe.

A free gracilis muscle flap for foot resurfacing, the first microsurgical case in a Sub-Saharan African country, Togo

In Togo, reconstructive management has been based on local and regional flaps. In some severe cases and in cases of failure, only a cross leg flap (if possible) or an amputation would save the patient. It has become vital to move forward in the reconstructive ladder in our setting. We report our first case of free gracilis muscle flap for the reconstruction of a foot defect in a 21-year-old male patient who was presented with a foot laceration due to a road traffic accident. The plastic surgeon had training in microsurgery. For other members of the operative team, this was the first microsurgery procedure. The gracilis muscle was harvested from the contralateral thigh and inset in the defect by microsurgical vascular anastomosis. The flap’s monitoring was done clinically. The post-operative course was uneventful. The muscle flap was resurfaced on day 5 using a split thickness skin graft. The patient was discharged on day 12. Total healing was seen on day 21. The patient was very satisfied with the procedure. The success of this first case represents an optimal motivation to build up a microsurgery team and the debut of microsurgery procedures for patients with difficult defects in Togo.

Technical Nuances of Exposing Rat Common Carotid Arteries for Practicing Microsurgical Anastomosis

Animal models are commonly used in training protocols for microsurgical vascular anastomosis. Rat common carotid arteries (CCAs) are frequently used for this purpose. Much attention has been paid to the technical details of various anastomosis configurations using these arteries. However, technical nuances of exposing rat CCAs have been understudied. The purpose of this study is to describe nuances of technique for safely and efficiently exposing rat CCAs in preparation for a vascular anastomosis. Bilateral CCAs were exposed and prepared for anastomosis in 10 anesthetized Sprague-Dawley rats through a midline cervical incision. The exposed length of the CCA was measured. Additionally, technical nuances of exposure and surgically relevant anatomic details were recorded. The CCAs were exposed from the sternoclavicular joint to their bifurcation (average length, 19.1 ± 2.8 mm). Tenets important for a safe and efficient exposure of the CCAs included 1) generous subcutaneous dissection to expose the external jugular veins (EJVs), 2) avoiding injury to or compression of the EJVs, 3) superior mobilization of the salivary glands, 4) division of internal jugular veins, 5) opening the carotid sheath at its midlevel and from medial to lateral, and 6) avoiding injury to the vagus nerve or sympathetic trunk. Using the principles introduced in this study, trainees may safely and efficiently expose rat CCAs in preparation for a bypass.

Abdominal Pocket Method as a Salvage Procedure for Vascular Insufficiency After Distal Digital Replantation

To assess the utility of abdominal pocketing of a deepithelialized reattached digit to allow for neovascularization as a salvage procedure for circulatory insufficiency after digital replantation. We performed this method in Tamai zone II cases in which microsurgical vascular anastomosis was expected to be difficult based on the findings at the initial operation. From 2008 to 2014, 5 injured digits from 5 patients (mean age, 34 years; range: 25-54 years) underwent the abdominal pocket method as a salvage procedure for postoperative circulatory insufficiency. We evaluated the survival incidence, the timing between operations, and the duration of the second operation. During this study period, 7 amputated digits from 7 patients underwent vascular reanastomosis. We also evaluated the survival incidence for these cases. Four out of 5 replanted digital tips survived. The mean time between the initial operation and the onset of vascular problems was 82 hours, and the mean duration of the second operation was 48 minutes. The survival incidence for reanastomosed cases was 6 out of7. The abdominal pocket method is useful for treating circulatory insufficiency after digital replantation in Tamai zone II cases in which microsurgical vascular reanastomosis was expected to be difficult based on the findings at the initial operation. Therapeutic IV.

Macrosurgery for fingertip amputations

Due to the high concentration of sensitive receptors, the fingertip is widely used in plenty of activities and, therefore, frequently exposed to trauma and amputation. Simple revision amputation was used in the past for the treatment of these injuries. However, replantation, revascularization, or reconstruction allows preservation of the nail, length of the digit, and, mainly, sensibility of the pulp. Undoubtedly, the best way to restore function to an amputated digit is to restore the amputated part by microsurgical vascular anastomosis. However, the replantation of very distal segments is technically challenging due to the size and fragility of the vessels. Furthermore, the amputated part is not always available. Reattachment of the amputated part without vascular anastomosis is described as composite graft [1]. Other authors described different ways for improving the success rate. Brent [2] described the reattachment in amputations that occurred between the lunula and the DIP joint by performing deepithelization of the amputated part and embedding it in a subcutaneous pocket in the contralateral chest. Arata et al. [3] modified this procedure using the ipsilateral palm as the pocket site. We consider subzone 1 Ishikawa level as suitable for reconstruction without replantation. In this case, a local flap can adequately restore function and appearance. The neurovascular homodigital advancement flap [4] is the most useful flap for coverage of the amputated part. For larger areas that cannot be covered with a homodigital advancement flap, we use innervated cross finger flaps [5]. The Moberg flap is a good option to reconstruct medium-size defects of the pulp of the thumb [6]. For covering larger areas, we use the first metacarpal island flap [7]. Raising a racket flap as proposed by Holevich [8] adds safety regarding venous congestion, once a subcutaneous tunnel is avoided, and can improve cold intolerance, since it transfers more nerve branches to the thumb allowing for a better temperature control [9]. The nail complex tissues, as hyponychium, paronychium, and sterile matrix cannot be reconstructed with local tissue. If the amputated part is available, these parts can be used as grafts applied to the flap used to reconstruct the pulp[10]. The eponychial flap [11] can be used to increase the exposed part of the nail bed. This is achieved by removing a rectangle of dorsal skin and performing a proximal translocation of the eponychium.

Multiple adjustable vascular clamp prototype: Feasibility study on an experimental model of end-to-side microsurgical vascular anastomosis

The aim of this study was to establish the feasibility of microsurgical end-to-side vascular anastomosis with a multiclamp adjustable vascular clamp prototype in an inert experimental model. Our method consisted of performing an end-to-side microsurgical anastomosis with 10/0 suture on a 2-mm diameter segment. In group 1, the end-to-side segment was held in place by a double clamp and a single end clamp. In group 2, the segment was held in place with a single multiclamp adjustable clamp. The average time for performing the anastomosis was shorter in group 2. The average number of sutures was the same in both groups. No leak was found and permeability was always positive in both groups. Our results show that performing end-to-side anastomosis with a multiclamp adjustable vascular clamp is feasible in an inert experimental model. Feasibility in a live animal model has to be demonstrated before clinical use.

The V-Plasty. A New Microsurgical Technique to Anastomose Vessels with Marked Size Discrepancy

Introduction: The purpose of this topic is to present an original, new way to achieve microsurgical vascular anastomoses between two vascular structures with a high diameter discrepancy. The V-Plasty - the name we gave to this technique - can accomplish the continuity of the vascular tube respecting the linear direction of the blood flow and avoiding the turbulences that are zones where blood cells may aggregate in blood clots.

Simulation of a High-Flow Extracranial-Intracranial Bypass Using a Radial Artery Graft in a Novel Fresh Tissue Model

Microsurgical vascular anastomosis techniques are technically challenging and used in only a narrow spectrum of neurosurgical procedures. Opportunities for instruction and application have become increasingly rare during standard neurosurgery residencies. To create a neurovascular simulation model that more closely approximates the clinical environment. This article describes a novel surgical model using vascular pressurization in a fresh cadaver to simulate an extracranial-to-intracranial bypass. Fresh cadavers were obtained according to the standard operating procedures of the University of Southern California Fresh Tissue Dissection Laboratory. The femoral vessels were cannulated and the entire cadaver pressurized. A high-flow bypass from the common carotid artery to the middle cerebral artery was performed using a radial artery graft. This system has several advantages for neurosurgical simulation. The fresh tissue reproduces intraoperative haptics and anatomy. Extracranial-to-intracranial bypass is a physically demanding procedure and can become fatiguing and frustrating for beginners. This model more closely simulates clinical operative time and conditions. The surgeon is able to rehearse the steps and progression of the operation as opposed to simply focusing on the anastomosis. Surgeon positioning and microscope placement are often difficult for novices. By simulating the operating room conditions, these steps can be practiced, providing experience that can be directly translated to the clinical arena. Despite the decrease in frequency, indications for bypass procedures still exist in neurosurgery. The fresh tissue pressurization model offers significant benefits when training neurosurgeons to perform these technically demanding procedures.

Arterial complications after liver transplantation: the impact of allocation of arteries to the donor liver in multi-organ retrieval

Objective To study the impact of allocation of organ arteries and their reconstruction for donor livers on arterial complications after liver transplantation from organ clusters obtained by combined liver,kidney,pancreas and duodenum harvesting.The aim is to guide future use of donor organs more safely and rationally with a decrease in postoperative complications.Method We studied 11 patients.Results There was no hepatic artery anomaly.A Carrol artery patch was obtained at the bifurcation of the proper hepatic artery and the gastroduodenal artery in these donor livers.In one patient,an arterial graft was used because of inadequate arterial length,and arterial thrombosis developed which required re-transplantation.The hepatic arterial reconstruction was successful for the remaining 10 patients.One patient died of pulmonary infection 5 months post transplantation.Conclusion When combined liver,kidney,pancreas and duodenum harvesting was used,enough arterial length of the recipient must be preserved.There should be adequate and prompt communication between the teams carrying out the donor operation and the recipient operation.A Carrol arterial patch of the proper hepatic artery and the gastroduodenal artery for the donor liver,and the use of microsurgical vascular anastomosis in the operation are the keys to prevent hepatic arterial complications after liver transplantation.Multi-organ harvesting can be used for obtaining donor livers in liver transplantation. Key words: Liver transplantation; Multi-organ retrieval; Arterial thrombosis

Robotic surgery in male infertility and chronic orchialgia

The use of robotic assistance during microsurgical procedures is currently being explored in the treatment of male infertility and patients with chronic testicular pain. Whether the addition of this technology would allow a corresponding improvement in outcomes as when the operating microscope was introduced in microsurgery is yet to be seen. The present review covers new robotic microsurgical tools and applications of the robotic platform in microsurgical procedures such as vasectomy reversal, varicocelectomy, denervation of the spermatic cord for chronic testicular pain and microsurgical vascular anastomosis. Preliminary animal studies appear to show an advantage in terms of improved operative efficiency and improved surgical outcomes. Preliminary human clinical studies appear to support these findings. The use of robotic assistance during robotic microsurgical vasovasostomy appears to decrease operative duration and significantly improve early postoperative sperm counts compared with the pure microsurgical technique. As with any new technology, long-term prospective controlled trials are necessary to assess the true cost-benefit ratio for robotic assisted microsurgery. The preliminary findings are promising, but further evaluation is warranted.

Tracheal transplant with a prefabricated microsurgical flap

To test the viability of a tracheal autotransplant, with an original technique using a prefabricated flap from a complete tracheal neovascularized segment (CTNVS) of the sternohyoid muscle anastomosed by a microsurgical technique. An experimental study using dogs as an animal model. Ten mongrel dogs weighing 23 to 40 kg were divided into two groups: group I (control), five animals submitted to autotransplant of the CTNVS without a microsurgical vascular anastomosis; and group II, five dogs submitted to autotransplant of the CTNVS with a microsurgical vascular anastomosis. All group I dogs developed respiratory insufficiency and died because of necrosis and stenosis of the autotransplanted CTNVS, whereas all group II dogs completed a minimum period of 90 days of observation without any clinical changes. Macro- and microscopic analysis revealed intact tracheal structures. The present clinical and morphological findings demonstrate that the CTNVS autotransplant is viable, when a microsurgical vascular anastomosis is used.

Time to re-think: ovarian tissue transplantation versus whole ovary transplantation

Transplantation of cryobanked ovarian tissue is a promising strategy to restore fertility in cancer patients. However, ischaemia following ovarian tissue grafting can lead to significant follicular loss. Transplantation of the whole ovary by vascular anastomosis has been considered as a method of preventing ischaemic damage that occurs with avascular transplantation of ovarian tissue. Even so, the unavailability of the cryotechnology for whole organs can be a major barrier to whole ovary transplantation. Severe cryoinjury will cause not only follicular death but also irreversible damage to the vascular system of the ovary. Damaged ovarian vasculatures can induce thromboembolism after transplantation which leads to severe tissue ischaemia and follicular loss. As a consequence, follicular loss after the frozen-thawed whole ovary was transplanted with microsurgical vascular anastomosis has been shown to be as severe as that which occurred after ovarian tissue was grafted. In addition, the risk of cancer cell reintroduction can be potentially higher with whole ovary transplantation with vascular anastomosis. The safety and efficacy of the new procedure should be proven before any further clinical applications take place. Nevertheless, research on whole ovary cryopreservation should not be discouraged.

Aesthetic Pubic Reconstruction After Electrical Burn Using a Portion of Hair-Bearing Expanded Free-Forehead Flap

Electrical burn in the pubic region usually results in a severe and contractive scar with pubic hair loss. The aesthetic restoration of this area often has become very difficult. A 22-year-old male electrical engineer experienced severe pubic scarring with hair loss after electrical burn. He was treated successfully with an expanded free-forehead flap including a portion of hair-bearing scalp after microsurgical vascular anastomoses between the bilateral superficial temporal vessels and the bilateral deep inferior epigastric vessels. The donor forehead site was closed directly in the frontal hairline without visible scarring. The pubic area was repaired functionally and cosmetically with the flap, and the pubic hair was growing well after a 1-year following-up period. This successful case strongly indicates that a microsurgical tissue transfer can be a good option for reconstruction of a pubic defect and that the expanded forehead flap could fulfill the high cosmetic demands of pubic reconstruction with minimal donor morbidity.