Vascular Reanastomosis Research Articles

Delayed breast reconstruction with autologous free flap after radiation therapy: vascular complications and aesthetic outcomes.

The safety and outcome of breast reconstruction after radiotherapy are controversial, and the aesthetic aspects have not been studied extensively. We compared the results of vascular anastomosis, the incidence of postoperative complications, and aesthetic appearance between patients who had and had not received radiotherapy who then had undergone delayed breast reconstruction with autologous free flaps from the abdomen, thighs, and buttocks. In total, 257 flaps in 241 patients were investigated; 194 and 63 flaps implanted in patients who did not receive radiotherapy and who received radiotherapy before breast reconstruction, respectively. Of the 257 flaps, 221, 20, 14, and 2 came from the abdomen, thighs, buttocks, and other anatomic locations, respectively. We evaluated aesthetic outcomes in 105 patients who had not received radiotherapy and 35 who had. We found no significant differences between the two groups in the incidence of vascular reanastomosis, the time required for anastomosis, or the incidence of unplanned reoperation. Complications such as flap necrosis were rare in both groups. Aesthetic outcomes were significantly better in the patients who had not received radiotherapy. Breast reconstruction with autologous free flaps can be performed safely in patients who have received radiotherapy, but the aesthetic result is slightly inferior to that in patients who had not received radiotherapy.

Clinical application of expanded internal mammary artery perforator flap combined with vascular supercharge in reconstruction of faciocervical scar

Objective: To summarize the clinical experience of expanded internal mammary artery perforator (IMAP) flap combined with vascular supercharge in reconstruction of faciocervical scar. Methods: The retrospective observational study was conducted. From September 2012 to May 2021, 23 patients with postburn or posttraumatic faciocervical scars who met the inclusion criteria were admitted to Shanghai Ninth People's Hospital of Shanghai Jiao Tong University School of Medicine, including 18 males and 5 females, aged from 11 to 58 years, all of whom were reconstructed with expanded IMAP flaps. At the first stage, one or two skin and soft tissue expander (s) with appropriate rated capacity were implanted in the anterior chest area according to the location and size of the scars. The IMAP, thoracic branch of supraclavicular artery, and lateral thoracic artery were preserved during the operation. The skin and soft tissue expanders were inflated with normal saline after the operation. The flaps were transferred during the second stage. The dominant IMAP was determined preoperatively using color Doppler ultrasound (CDU) blood flow detector. The faciocervical scars were removed, forming wounds with areas of 9 cm×7 cm-28 cm×12 cm, and the perforators of superficial temporal artery and vein or facial artery and vein were preserved during the operation. The flaps were designed according to the area and size of the wounds after scar resection with the dominant IMAP as the pedicle. Single-pedicle IMAP flaps were used to repair small and medium-sized wounds. For larger defects, the blood perfusion areas of vessels in the anterior chest were evaluated by indocyanine green angiography (ICGA). In situations where the IMAP was insufficient to nourish the entire flap, double-pedicle flaps were designed by using the thoracic branch of supraclavicular artery or lateral thoracic artery for supercharging. Pedicled or free flap transfer was selected according to the distance between the donor areas and recipient areas. After transplantation of flaps, ICGA was conducted again to evaluate blood perfusion of the flaps. The donor sites of flaps were all closed by suturing directly. Statistics were recorded, including the number, rated capacity, normal saline injection volume, and expansion period of skin and soft tissue expanders, the location of the dominant IMAP, the total number of the flaps used, the number of flaps with different types of vascular pedicles, the flap area, the flap survival after the second stage surgery, the occurrence of common complications in the donor and recipient areas, and the condition of follow-up. Results: Totally 25 skin and soft tissue expanders were used in this group of patients, with rated capacity of 200-500 mL, normal saline injection volume of 855-2 055 mL, and expansion period of 4-16 months. The dominant IMAP was detected in the second intercostal space (20 sides) or the third intercostal space (5 sides) before surgery. A total of 25 expanded flaps were excised, including 2 pedicled IMAP flaps, 11 free IMAP flaps, 4 pedicled thoracic branch of supraclavicular artery+free IMAP flaps, and 8 free IMAP+lateral thoracic artery flaps, with flap areas of 10 cm×8 cm-30 cm×14 cm. After the second stage surgery, tip necrosis of flaps in three patients occurred, which healed after routine dressing changes; one patient developed arterial embolism and local torsion on the vascular pedicle at the anastomosis of IMAP and facial artery, and the blood supply recovered after thrombectomy and vascular re-anastomosis. Fourteen patients underwent flap thinning surgery in 1 month to 6 months after the second stage surgery. The follow-up for 4 months to 9 years showed that all patients had improved appearances of flaps and functions of face and neck and linear scar in the donor sites of flaps, and one female patient had obvious nipple displacement and bilateral breast asymmetry. Conclusions: The expanded IMAP flap is matched in color and texture with that of the face and neck, and its incision causes little damage to the chest donor sites. When combined with vascular supercharge, a double-pedicle flap can be designed flexibly to further enhance the blood supply and expand the flap incision area, which is a good choice for reconstruction of large faciocervical scar.

Single stage risk-reducing breast and gynecologic surgery for hereditary predisposition to breast and ovarian cancer

Objectives: We sought to evaluate the perioperative outcomes of patients undergoing single-stage breast and gynecologic surgery for either breast cancer or a hereditary breast and ovarian cancer syndrome (HBOC). Methods: All patients with documented genetic testing undergoing single-stage breast and gynecologic extirpative surgery for breast cancer or an HBOC syndrome with or without immediate breast reconstruction were included. Perioperative outcomes including intraoperative, Results: Forty-three patients underwent single-stage surgery between September 2015 and July 2020 at a single academic tertiary referral hospital. Most patients underwent combined surgery for breast cancer (81.3%) and concurrent gynecologic prophylaxis (97.7%). Median patient age was 48 years and median BMI was 26.8 kg/m2. There were 33 patients (76.7%) with a pathogenic genetic mutation, the most common of which was BRCA1 (41.9%). All breast surgeries were mastectomies, 90.7% of which were bilateral; 48.8% included axillary lymph node dissection. The majority (88.4%) of breast extirpative procedures were followed by immediate reconstruction. The gynecological procedures were most commonly performed via conventional laparoscopy (55.8%): Fifty-eight percent of patients underwent total hysterectomy and bilateral salpingo-oophorectomy (BSO) and 37.5% underwent BSO alone. Median total operative time was 459.5 minutes (74-818 min). Median length of hospital stay was four days (1-14 d), and median estimated blood loss was 25cc (25-200 cc). The only intraoperative complication was a breast reconstructive flap failure that required vascular reanastomosis. Overall, 34.8% of patients had a complication. Complications during the first 30 post-operative days included four readmissions for reoperation, one venous thromboembolism (VTE), two transfusions, and nine complications of breast surgery (three hematomas, three wound dehiscences, and three surgical site infections). Six of these patients required reoperation Download : Download high-res image (91KB) Download : Download full-size image Conclusions: Single-stage breast and risk-reducing gynecologic surgeries are associated with similar complication rates to multi-stage surgeries with the benefit of providing the patient with a single recovery period. Further studies are encouraged to motivate multi-disciplinary collaboration with the ultimate goal of shorter overall recovery time for patients with breast cancer or an HBOC syndrome.

Whole Ovary Cryopreservation and Transplantation: A Systematic Review of Challenges and Research Developments in Animal Experiments and Humans.

Ovarian tissue cryopreservation and transplantation is the only fertility preservation option that enables both restoration of fertility and resumption of ovarian endocrine function, avoiding the morbidity associated with premature menopause. It is also the only technique available to prepubertal patients and those whose treatment cannot be delayed for life-threatening reasons. Ovarian tissue cryopreservation can be carried out in two different ways, either as ovarian cortical fragments or as a whole organ with its vascular pedicle. Although use of cortical strips is the only procedure that has been approved by the American Society for Reproductive Medicine, it is fraught with drawbacks, the major one being serious follicle loss occurring after avascular transplantation due to prolonged warm ischemia. Whole ovary cryopreservation involves vascular transplantation, which could theoretically counteract the latter phenomenon and markedly improve follicle survival. In theory, this technique should maintain endocrine and reproductive functions much longer than grafting of ovarian cortical fragments. However, this procedure includes a number of critical steps related to (A) the level of surgical expertise required to accomplish retrieval of a whole ovary with its vascular pedicle, (B) the choice of cryopreservation technique for freezing of the intact organ, and (C) successful execution of functional vascular reanastomosis upon thawing. The aim of this systematic review is to shed light on these challenges and summarize solutions that have been proposed so far in animal experiments and humans in the field of whole ovary cryopreservation and transplantation.

Limb salvage procedures for mutilated forearm injuries

Objective To report the limb salvage experience in patients with mutilated forearm severance. Methods From September 2012 to October 2014, 8 severed forearms with mutilated injuries were salvaged by shortening and replantation of the forearm after emergency debridement. Results The replants survived in all 8 cases. Postoperative follow-up ranged from 6 to 24 months. Based on the evaluation criteria for the upper extremity issued by the Hand Surgery Society of the Chinese Medical Association, functions of the salvaged forearms were rated as excellent in 1 case, good in 5 cases, and poor in 2 cases. Postoperative complications included arterial crisis in 1 case that was rescued by surgical exploration and vascular re-anastomosis; severe infection in 1 case that was successfully managed with antibiotics treatment; forearm fracture nonunion in 1 case that was healed with secondary fixation and bone graft; and tendon adhesion in 1 case that was treated with secondary tenolysis. Conclusion Limb-salvage procedures should be considered in mutilated forearm severance cases when conditions allow. Reasonable functional outcomes can be expected. Key words: Forearm; Treatment outcome; Mutilated injuries; Limb salvage

Decellularized skin/adipose tissue flap matrix for engineering vascularized composite soft tissue flaps

Using a perfusion decellularization protocol, we developed a decellularized skin/adipose tissue flap (DSAF) comprising extracellular matrix (ECM) and intact vasculature. Our DSAF had a dominant vascular pedicle, microcirculatory vascularity, and a sensory nerve network and retained three-dimensional (3D) nanofibrous structures well. DSAF, which was composed of collagen and laminin with well-preserved growth factors (e.g., vascular endothelial growth factor, basic fibroblast growth factor), was successfully repopulated with human adipose-derived stem cells (hASCs) and human umbilical vein endothelial cells (HUVECs), which integrated with DSAF and formed 3D aggregates and vessel-like structures in vitro. We used microsurgery techniques to re-anastomose the recellularized DSAF into nude rats. In vivo, the engineered flap construct underwent neovascularization and constructive remodeling, which was characterized by the predominant infiltration of M2 macrophages and significant adipose tissue formation at 3months postoperatively. Our results indicate that DSAF co-cultured with hASCs and HUVECs is a promising platform for vascularized soft tissue flap engineering. This platform is not limited by the flap size, as the entire construct can be immediately perfused by the recellularized vascular network following simple re-integration into the host using conventional microsurgical techniques. Statement of SignificanceSignificant soft tissue loss resulting from traumatic injury or tumor resection often requires surgical reconstruction using autologous soft tissue flaps. However, the limited availability of qualitative autologous flaps as well as the donor site morbidity significantly limits this approach. Engineered soft tissue flap grafts may offer a clinically relevant alternative to the autologous flap tissue. In this study, we engineered vascularized soft tissue free flap by using skin/adipose flap extracellular matrix scaffold (DSAF) in combination with multiple types of human cells. Following vascular reanastomosis in the recipient site, the engineered products successful regenerated large-scale fat tissue in vivo. This approach may provide a translatable platform for composite soft tissue free flap engineering for microsurgical reconstruction.

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.

Modified Uterine Allotransplantation and Immunosuppression Procedure in the Sheep Model

ObjectiveTo develop an orthotopic, allogeneic, uterine transplantation technique and an effective immunosuppressive protocol in the sheep model.MethodsIn this pilot study, 10 sexually mature ewes were subjected to laparotomy and total abdominal hysterectomy with oophorectomy to procure uterus allografts. The cold ischemic time was 60 min. End-to-end vascular anastomosis was performed using continuous, non-interlocking sutures. Complete tissue reperfusion was achieved in all animals within 30 s after the vascular re-anastomosis, without any evidence of arterial or venous thrombosis. The immunosuppressive protocol consisted of tacrolimus, mycophenolate mofetil and methylprednisolone tablets. Graft viability was assessed by transrectal ultrasonography and second-look laparotomy at 2 and 4 weeks, respectively.ResultsViable uterine tissue and vascular patency were observed on transrectal ultrasonography and second-look laparotomy. Histological analysis of the graft tissue (performed in one ewe) revealed normal tissue architecture with a very subtle inflammatory reaction but no edema or stasis.ConclusionWe have developed a modified procedure that allowed us to successfully perform orthotopic, allogeneic, uterine transplantation in sheep, whose uterine and vascular anatomy (apart from the bicornuate uterus) is similar to the human anatomy, making the ovine model excellent for human uterine transplant research.

The effects of whole ovarian perfusion and cryopreservation on endothelial cell-related gene expression in the ovarian medulla and pedicle

Fertility preservation by whole ovarian cryopreservation requires successful cryopreservation of both the ovary and its vascular supply. Previous work has indicated detrimental effects of both perfusion and cryopreservation on the ovarian vasculature. This study assessed the effects of blood perfusion, alone or in combination with cryopreservation, on functional effects in the follicle population and ovarian function in vivo following short-term autotransplantation of the tissue after vascular reanastomosis and measured acute changes in endothelial cell-related gene expression within the ovarian medulla and pedicle. Following autotransplantation for 7 days, primordial, transitional and primary follicle densities were significantly reduced (P < 0.05) and stromal Ki67 and caspase-3 expression significantly increased (P < 0.05) in cryopreserved but not fresh or perfused whole ovaries. There was evidence of clot formation and fluorescent microsphere (FMS) extravasation in the medulla of all cryopreserved ovaries, indicating vascular damage. Utilizing a customized RT-PCR array or conventional RT-PCR, we found that perfusion alone resulted in down-regulation in the expression of caspase 6 and thrombospondin 1 (THBS1) genes in the medulla. Following additional cryopreservation, endothelial nitric oxide synthase (eNOS), endothelin 1, endothelin receptor A and Bcl-2 expression were significantly (P < 0.05) down-regulated. In the pedicle, both perfusion and cryopreservation caused a (P < 0.05) down-regulation of eNOS and THBS1, and an up-regulation in Bax expression. Perfusion also caused a down-regulation of TNF and up-regulation of endothelin-2 expression (P < 0.05). In conclusion, this study has identified a number of endothelial cell-related genes expressed in the medulla which are acutely affected by both cryopreservation and perfusion, supporting the hypothesis that both interventions have deleterious effects on endothelial cell function.

2074 IMPACT OF CLINICAL CHARACTERISTICS AND PRETRANSPLANT URINARY BLADDER CAPACITY ON URODYNAMICS ONE YEAR POSTTRANSPLANTATION IN 54 ADULT RECIPIENTS

of urine output and was confirmed by Doppler US and Magnetic Resonance Angiography. Mean time interval between tx and occurrence was 4.6 9 and 15 13 days in RAT and RVT, respectively. Mean time interval between oliguria or anuria and surgical exploration was (60 14.8) and (48.7 14.3) minutes for RAT and RVT, respectively. The graft was saved in 15 (65.2%) and lost in 8 (34.8%) patients. All cases of RAT were treated by open surgery. Intervention included discontinuation of the arterial anastomosis and thrombectomy, then venotomy was done under proximal control of the renal vein followed by perfusion of the graft with heparinized cold saline until perfusate became clear, finally vascular re-continuity was restored. The graft had been saved in 12 (63%) out of 19 patients with RAT. RVT occurred in 4 patients, the graft had been saved in 3 patients by angiographic local injection of streptokinase in 2 patients and open vascular re-anastomosis after removal of the thrombus in one. On univariate and multivariate analysis, no preoperative factors e.g. time to diagnosis were found to be significantly affecting salvage of the graft. CONCLUSIONS: Vascular accidents are uncommon events after renal transplantation. Strict follow-up of renal transplant patient is mandatory and immediate diagnosis is crucial for graft salvage. Angiographic local injection of streptokinase in graft vein is a viable alternative for graft survival.

Versatility of Free SCIA/SIEA Flaps in Head and Neck Defects

Reconstruction of head and neck defects may require replacement of the bony structures, external soft tissue, and intraoral mucosa. Most cases, including maxillary defects, often require repair using only soft tissue flaps. Recently, the authors used free superficial circumflex iliac artery/superficial inferior epigastric (SCIA/SIEA) flaps for head and neck reconstruction. This was their first choice over other free flaps due to its versatile advantages. Fifteen patients underwent head and neck reconstruction with free SCIA/SIEA flaps (n = 16). No flap loss was observed; however, emergency vascular reanastomosis was performed in 3 cases to restore the blood supply in compromised flaps. Flap thinning and secondary debulking procedures were performed in 4 cases. The functional and aesthetic results were deemed as acceptable in all patients. Based on our results, we believe that the free SCIA/SIEA flap is useful for soft tissue defect reconstruction in the head and neck. It has the following advantages: (1) Large flap elevation is possible for reaching distant recipient vessels, (2) Two surgical teams may work at the same time preparing the donor and recipient regions, and (3) The flap design uses an abdominoplasty incision, which has minimal donor site morbidity.

Analysis of 59 cases with free flap thrombosis after reconstructive surgery for head and neck cancer

Objective There have been few reports addressing methods of dealing with free flap thrombosis after reconstructive surgery for head and neck cancer. The present study, through a detailed analysis of the subsequent course of patients who developed postoperative flap thrombosis, aims to clarify possible methods of salvage surgery in the event of vascular occlusion despite rigorous postoperative follow-up. Methods We analyzed 59 cases of postoperative thrombosis in 1031 patients who underwent free flap transfer and considered the most appropriate salvage surgery in the event of total flap necrosis. Results The flap salvage rate through vascular reanastomosis was highest for radial forearm flaps, with salvage of jejunal flaps being problematic if postoperative thrombosis occurred. For cases of postoperative thrombosis among patients who underwent reconstruction using a jejunal flap, the period of hospitalization was significantly extended for those patients in whom a second jejunal flap grafting was impossible. For cases of postoperative thrombosis among patients who underwent reconstruction using a radial forearm flap (FA), rectus abdominis flap (RA), or anterior lateral thigh flap (ALT), no significant difference was observed between those undergoing re-grafting with a free flap and those with a pedicled flap. Conclusion We concluded that, among patients who undergo reconstruction using a jejunal flap, thrombosis should be discovered at an early stage to enable another jejunal flap re-grafting. For patients who undergo reconstruction using a FA, RA, or ALT, if thrombosis can be discovered at an early stage, there is a possibility of salvaging the flap by means of vascular reanastomosis. If it should prove impossible to salvage the flap, however, primary suture of the defect or reconstruction with a pedicled flap may also be considered.

Repair of soft tissue defect on dorsum of the hand with free dorsalis pedis flap

Objective To evaluate the clinical outcomes of repairing soft tissue defect on dorsum of the hand by free dorsalis pedis flap transfer. Methods Ten cases of soft tissue defects on dorsum of the hand were treated. Dorsalis pedis flap including the superficial peroneal nerve was harvested and transferred to cover the defects. In one of the 10 cases, the 3rd and 4th toe extensor tendons were also included in the flap. In the other case, the second toe was transferred simultaneously to reconstruct the middle finger. The sizes of the harvested flaps ranged from 5 cm x 4 cm to 21 cm 12 cm. Results All 10 flaps survived. Postoperative vascular crisis occurred in 1 ease. Surgical exploration revealed venous thrombosis. The flap survived after resection of the thrombotic site and vascular re-anastomosis. Postoperative follow up period was 6 to 24 months. In 9 eases the flaps were not bulky. The texture and color of the skin were near normal. Partial recovery of pain, temperature and touch sensation was observed. In 1 ease the skin was dark and hard. Necrosis of skin grafts at the donor site with exposed tendons was seen in 3 cases. One case healed secondarily after dressing change; one was treated by transferring medial fascial flap from the lower leg; one case was repaired with medial tarsal island flap. Conclusion Composite dorsalis pedis flap is an ideal mehed to repair defects of skin, tendon and nerve on dorsum of the hand. Key words: Flaps; Hand injuries; Transplantation; Repair

Successful Ovarian Autotransplant With No Vascular Reanastomosis in Rats

Preservation of ovarian functions in woman with premature ovarian failure remains an issue in reproductive medicine. Hormone replacement therapy for maintaining endocrine functions, and cryopreservation of embryos or oocytes for those who wish pregnancy, are some of the choices. However, ovarian transplantation is a more physiological alternative, although problems related to ovarian ischemia have been reported. Herein, we investigated the viability of autologous transplantation of the ovarian tissue into the rat peritoneum, without vascular reanastomosis. Twenty animals in the study group had both ovaries excised, and each ovary was dissected into two halves. A half of an ovary was autotransplanted to the peritoneal surface, closely located to the left epigastric vessels. This simple procedure does not require surgical vascular reanastomosis while it maintains appropriate follicular growth and therefore should be further considered as an alternative for women undergoing oophorectomy, not only to maintain endocrine functions but also for fertility preservation.

Advancements made in reproductive research for human uterine transplants

OBJECTIVE: The purpose of this project is three-fold: (1) to investigate in a sheep and goat model of uterine transplantation after utero-ovarian ligation and uterine vessel reanastomosis (2) assess tissue rejection and endometrial changes that occur by histological studies and (3) to determine a success rate of pregnancy after a successful uterine transplant.DESIGN: Pilot study.MATERIALS AND METHODS: Our research project explores feasibility of uterine transplantation by comparing vascular changes, uterine morphology and tissue viability in the uterine auto (n-4 goats) and allo-transplant model (n-10 sheep). The sheep and goat model were preferred since the anatomical land marks and vascular anatomy are comparable to human with the exception of a bicornuate uterus in the sub-primate model. The short-term effects of warm and cold tissue ischemia were quantified and uterine tissue reperfusion were analyzed after vascular reanastomosis. The goats were naturally mated with a buck and the sheep were synchronized with progesterone implants for the preparation of an embryo transfer. Our endpoint is delivery of healthy offspring from both the auto and allo-transplanted groups.RESULTS: Our results demonstrate vascular patency and complete tissue reperfusion of blood in our 14 animals within 30 seconds after vascular reanastomosis without evidence of arterial or venous thrombosis. At six months post-uterine transplantation, hysterectomies were performed documenting viable uterine tissue and vascular patency in six out of the ten uterine allo-transplants. The presence of functional ovarian tissue and fallopian tube patency was documented in two of the four transplanted goat models. One of our uterine auto-transplanted goats delivered two health offspring by natural mating.CONCLUSIONS: We have developed a modified surgical procedure that has allowed us to perform successful uterine transplants in the sub-primate model. Our pilot study demonstrates that the ewe and goat are excellent models for uterine transplant research. By exploring the different alternatives for uterine factor fertility such as adoption and surrogacy, the uterine transplant may be considered another alternative for infertility. OBJECTIVE: The purpose of this project is three-fold: (1) to investigate in a sheep and goat model of uterine transplantation after utero-ovarian ligation and uterine vessel reanastomosis (2) assess tissue rejection and endometrial changes that occur by histological studies and (3) to determine a success rate of pregnancy after a successful uterine transplant. DESIGN: Pilot study. MATERIALS AND METHODS: Our research project explores feasibility of uterine transplantation by comparing vascular changes, uterine morphology and tissue viability in the uterine auto (n-4 goats) and allo-transplant model (n-10 sheep). The sheep and goat model were preferred since the anatomical land marks and vascular anatomy are comparable to human with the exception of a bicornuate uterus in the sub-primate model. The short-term effects of warm and cold tissue ischemia were quantified and uterine tissue reperfusion were analyzed after vascular reanastomosis. The goats were naturally mated with a buck and the sheep were synchronized with progesterone implants for the preparation of an embryo transfer. Our endpoint is delivery of healthy offspring from both the auto and allo-transplanted groups. RESULTS: Our results demonstrate vascular patency and complete tissue reperfusion of blood in our 14 animals within 30 seconds after vascular reanastomosis without evidence of arterial or venous thrombosis. At six months post-uterine transplantation, hysterectomies were performed documenting viable uterine tissue and vascular patency in six out of the ten uterine allo-transplants. The presence of functional ovarian tissue and fallopian tube patency was documented in two of the four transplanted goat models. One of our uterine auto-transplanted goats delivered two health offspring by natural mating. CONCLUSIONS: We have developed a modified surgical procedure that has allowed us to perform successful uterine transplants in the sub-primate model. Our pilot study demonstrates that the ewe and goat are excellent models for uterine transplant research. By exploring the different alternatives for uterine factor fertility such as adoption and surrogacy, the uterine transplant may be considered another alternative for infertility.

Modified Uterine Transplant Procedure in the Sheep Model

Study Objective The purpose of this project is to develop a uterine transplant procedure in the sheep model that may be suitable for human uterine transplants. Design Pilot study (Canadian Task Force classification II-2). Setting University De La Salle Bogotá, Colombia. Patients A total of 10 sexually matured sheep undergoing uterine allotransplantation. Interventions Uterine transplantation through a minilaparotomy incision with the application of a 900-500 modified Mobius retractor device. Measurements and Main Results The short-term effects of warm and cold tissue ischemia were quantified and uterine tissue reperfusion was analyzed after vascular reanastomosis. The ovine model was preferred since the anatomical landmarks and vascular anatomy are comparable to the human with the exception of a bicornuate uterus in the subprimate model. A modified surgical procedure was applied to our uterine allotransplanted sheep (n = 10) and tissue rejection was managed with cyclosporine therapy. A total abdominal hysterectomy without oophorectomy was performed and a cold ischemic time of 45 minutes was recorded. The uterine arteries and veins were reapproximated using a continuous end-to-end noninterlocking approach. Vascular patency and uterine tissue viability were assessed by histological studies. Complete tissue reperfusion of blood was achieved in our 10 animals within 30 seconds after vascular reanastomosis without evidence of arterial or venous thrombosis. At 6 months postuterine transplantation, hysterectomies were performed documenting viable uterine tissue and vascular patency in 6 out of the 10 uterine allotransplants. The site of uterine vessel reanastomosis was patent and histological studies indicated neovascularization with presence of smooth muscle and glandular endometrial tissue. Conclusion We have developed a modified procedure that has allowed us to perform successful uterine transplants in the sheep model. This is the first reported case in the literature documenting a successful procedure of uterine allotransplantation in the ewe. Our pilot study demonstrates that the ewe is an excellent model for uterine transplant research and with further studies; we plan to demonstrate that a pregnancy can be achieved after a successful uterine transplant.

Milrinone Does Not Improve Free Flap Survival in Microvascular Surgery

Free flap microvascular surgery involves the transfer of a mobilised tissue flap with complete vascular re-anastomosis at the new site. Ischaemia frequently threatens flap survival and may require a return to the operating theatre for anastomotic revision. Arterial spasm and hypoperfusion are recognised as factors in flap ischaemia. Phosphodiesterase inhibitors such as milrinone may improve flap blood flow and possibly flap survival by arterial dilation and increasing cardiac output. To investigate the role of milrinone in this type of surgery, a double-blinded randomised controlled trial was conducted with 88 patients receiving either a milrinone bolus and infusion throughout surgery or placebo (normal saline). We found that milrinone did not improve graft survival, return to theatre rate, or surgically graded arterial spasm, but did require more vasopressor support. We conclude that intraoperative milrinone did not improve flap outcomes in microvascular surgery.