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Microsurgery

Distribution by Scientific Domains
Medical Sciences99%

Kinds of Microsurgery

  • endoscopic microsurgery
  • laser microsurgery
    		•
  • reconstructive microsurgery
  • transanal endoscopic microsurgery
    		•
  • transoral laser microsurgery

    • Selected Abstracts

    Microsurgical treatment for bilateral thumb defect: Five case reports

    MICROSURGERY, Issue 6 2003
    Lei Xu M.D., Ph.D.
    The authors present a new and efficient treatment for reconstruction of bilateral defective thumbs by different configured toe-tissuestransplantations in a single stage, including bilateral second-toe transfer in 2 cases, bilateral hallux wrap-around flap transfer in 1 case, bilateral modified hallux wrap-around flap transfer in 1 case, and combined second toe with island flap with neurovascular pedicles from the proximal and dorsal aspect of the index finger transfer in 1 case. In total, eight transferred tissues survived uneventfully after circulation monitor and medicine administration according to the rules of microsurgery, and in two other transferred toe tissues, temporary circulation crises occurred. Over a 1-year follow-up, the satisfactory appearance and excellent function of the reconstructed bilateral thumbs were noted. For ensuring the success of the procedure, the authors emphasize the establishment of a double artery supply and venous return-flow systems and the modification of the hallux wrap-around flap dissection and tendon repair. Meanwhile, three-stage systemically functional rehabilitations also improved functional restoration of reconstructed thumbs. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:547,554 2003 [source]

    Transplantation and microsurgical anastomosis of free omental grafts: Experimental animal model of a new operative technique in dogs

    MICROSURGERY, Issue 5 2003
    Jozsef Pap-Szekeres M.D.
    Our objective was the elaboration of a new animal model for the free transplantation of an omental flap and the examination of its viability in dogs. The cooled omental flap from the abdomen was freely transplanted to the lateral cervical region, and its blood supply was established with microsurgical anastomoses. The technique was developed in 5 dogs, and short-term survival examinations were later carried out in 3 cases by means of this method. Postoperative viability was assessed by angiography, methylene blue testing, and histology. Of the 3 transplanted grafts, 2 still survived 1 week after the operation. For technical reasons, 1 flap thrombotized. For determination of the viability of the transplanted graft, histology proved best. Vital reactions, including granulation tissue and angiogenesis, were present on the histological slides. The short-term survival of an omental flap can be ensured with microsurgical transplantation in dogs. A cseplesz lebeny szabad átültetésére, valamint az átültetett lebenyek életképességének vizsgálata céljából új állatkísérletes modellt dolgoztunk ki. Módszerünket 5 állaton dolgoztuk ki, majd további 3, m,tött állatnál rövidtavu túlélési vizsgálatokat végeztünk. Hasüregb,l nyert, megfelel,en el,készített és h,tött cseplesz lebenyt szabadon ültettünk át a laterális nyaki régióra. Az átültetett lebeny érellátását mik-rosebészeti módszerrel létrehozott anasztomózisokkal biztosítottuk. Az átültetett lebenyek életképességét angiográfia, metilénkék-festés és szövettani módszerekkel vizsgáltuk. A 3 átültetett lebeny közül 2 életképesnek bizonyult 1 héttel a m,tét után, technikai ok miatt 1 lebeny trombotizált. Az életképesség igazolására a szövettani vizsgálat bizonyult a legjobbnak, melynek segítségével granulációs szövet és angiogenezis is ábrázolható volt. Cseplesz lebeny rövidtávú túlélése biztosítható mikrosebészeti módszerrel történ, átültetéssel kutyán. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:414,418 2003 [source]

    Multiorgan transplantation with a new organ-chip technique in mice: Preliminary histological data

    MICROSURGERY, Issue 5 2003
    Endre Brath M.D.
    A simple model was developed for multiorgan liver-kidney-spleen-intestine transplantation on 108 inbred mice. Donor operations included hepatectomy, nephrectomy, splenectomy, and jejunum segment resection. Following removal of the organ, small slices or abdominal organ "chips" were prepared. During multiorgan recipient operations, chips from each of these organs were transplanted into the omentum; in the control single-organ groups, only 1 organ was transplanted. All animals survived. Biopsies were taken for histology after 6 weeks. All organs were found to have developed a blood supply. In the liver chips, hypertrophied cells could be detected. In the margin of the kidney tissue, both the glomeruli and tubules were preserved. Lymphoid zone and red pulp were intact in spleen chips. All layers of the intestinal chips were identifiable and contained intraluminal mucinous substances. This model is a simple surgical intervention with the possibility of the investigation of 4 organs. Kísérletünk célja új, multiorgan máj-vese-lép-vékonybél chip-transzplantációs modell kidolgozása volt egerekben. Kísérletünkhöz 108 beltenyésztett egeret használtunk. Donor m,tétek: hepatectomia, nephrectomia, splenectomia, és jejunum segment resectio. Az eltávolított szervekb,l kis szeleteket, "chip"-eket alakítottunk ki. A multiorgan recipiens m,tétek: minden szervb,l darabokat transzplantáltunk a csepleszbe, míg kontrollba csak egy szerv került. Minden állat túlélt: 6 hét múlva szövettani mintavétel történt. A chip-vérellátás jól követhet, volt. A máj "chip"-ekben hipertrophiás sejteket találtunk. A vese darabok széli részén a glomerolusok és tubulusok meg,rízték szerkezetüket. Jól körülírt lép fészkeket detektáltunk lympoid zónával és vörös pulpával. A bél falának minden rétegét, és mucin termelést sikerült azonosítani. A modell technikailag egyszer,en kivitelezhetü, el,nye, hogy egyszerre 4 szerv vizsgálatára van lehet,ség. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:466,469 2003 [source]

    Rat liver transplantation for total vascular reconstruction, using a suture method

    MICROSURGERY, Issue 5 2003
    Seiichiro Inoue M.D.
    We developed a novel protocol for rat orthotopic liver transplantation (OLT), using a suture method to establish hepatic artery flow. After determining that early inferior vena cava (IVC) unclamping maintained better circulation compared with the portal vein (PV) using porto-systemic shunted recipients, we developed a rat OLT model with total vascular reconstruction using a suture method. After connecting the suprahepatic IVC, the infrahepatic IVC was anastomosed, using a running suture method. IVC circulation was established immediately. The PV was anastomosed without intestinal congestion, using porto-systemic shunted recipients. The aortic conduit, including the donor celiac and hepatic artery, was anastomosed to the recipient abdominal aorta end-to-side. Eight of 11 OLT cases (72.7%) survived indefinitely. Biliary connection was achieved using a one-stent method. Three cases died 3,5 days postoperatively. Hepatic angiography showed good patency. The graft liver was histologically normal in long-surviving rats. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:470,475 2003 [source]

    Synergistic effects of RAD and Neoral in inhibition of host-vs.-graft and graft-vs.-host immune responses in rat small-bowel transplantation

    MICROSURGERY, Issue 5 2003
    Stéphane Johnson M.Sc.
    The combined effects of RAD and Neoral were tested in a rat orthotopic small-bowel transplantation model. Seven groups (n = 6) were involved in this study, and each one was included in three rejection models for the evaluation of host-vs.-graft disease (HVG) (LBN-F1 to LEW), graft-vs.-host disease (GVH) (LEW to LBN-F1), and combined HVG and GVH immune responses (BN to LEW). Both drugs were administered orally throughout the study. Low doses of RAD (1.0,2.5 mg/kg/day) combined with Neoral (2.0,5.0 mg/kg/day) produced strong synergistic effects in the prolongation of small-bowel graft survival in HVG (combination index, CI = 0.095, 0.1212), GVH (CI = 0.027, 0.020), and combined HVG and GVH immune responses (CI = 0.070, 0.301). The combination therapy of RAD and Neoral produces a strong synergistic effect toward the inhibition of HVG, GVH, and combined HVG and GVH immune responses in a rat small-bowel transplantation model. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:476,482 2003 [source]

    Microsurgical tracheotomy: A pediatric model in growing rats

    MICROSURGERY, Issue 5 2003
    Mônica Cecília Bochetti Manna M.D.
    Previous studies described controversial opinions about pediatric tracheotomy concerning type of tracheal incision and long-term results, which remain as important research subjects. Experimental studies on rat tracheas are scarce, probably because of technical difficulties related to the structures' small dimensions. As many rat organ and system operative procedures were studied successfully by using microsurgical techniques, we decided to develop a pediatric tracheotomy model in growing rats which would permit long-term studies. Forty-four Wistar EPM-1 growing rats weighing 86 g and aged 35 days were divided into three groups: submitted to longitudinal, transverse, and segment excision of the trachea. Under sterile technique and intramuscular anesthesia (ketamine/xylazine), the trachea was exposed and incised, according to group, and a hand-made endotracheal cannula was inserted into the organ. This cannula was assembled using a segment of 1.5-cm-long 3 French silicone catheter passed through hexagonal-shaped silicone screen. The tracheal cannula was removed after 7 days, when we evaluated body weight, secretions, and dehiscence. In conclusion, this microsurgical tracheotomy model in growing rats is feasible, allowing studies on long-term repercussions of pediatric tracheotomy. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:530,534 2003 [source]

    Strain differences in autotomy in mice after peripheral nerve transection or repair

    MICROSURGERY, Issue 4 2003
    Roee E. Rubinstein A.B.
    The purpose of this study was to identify the optimal murine model for the study of peripheral nerve injury and nerve and limb transplantation. The degree of self-mutilation (autotomy) following sciatic and saphenous nerve injury was assessed in four mouse strains, Balb/C, C57BL/6J, C57BL/10J, and C3HEB, commonly used in surgical research. Experimental groups included sciatic and saphenous nerve transection with repair (n = 9) or without repair (n = 9), as well as housing arrangements favoring social interaction vs. isolation. Autotomy was most prevalent in the Balb/c and C3H strains at 56% and 89% overall, respectively, and was much less frequently seen in the C57Bl/10 and C57Bl/6 strains (22% and 11%, respectively). Autotomy was found to correlate most strongly with mouse strain, and with social contact as well. Two strains, C57BL/6J and C57BL/10J, were found to be highly resistant to self-mutilation, and are thus ideal animal models for peripheral-nerve and whole-limb transplant studies. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:363,368 2003 [source]

    Ultrarapid nonsuture mated cuff technique for renal transplantation in rabbits

    MICROSURGERY, Issue 4 2003
    Jun Wu M.D., Ph.D.
    An effective and ultrarapid technique for kidney transplantation in the rabbit is introduced. Vascular anastomosis was completed using a novel cuff technique in which mating cuffs were used to join the delicate renal vein. The ureter was reconstructed by spatulated end-to-end anastomosis, with special attention to the rabbit's unique ureteral vascular anatomy. The total vascular anastomosis time was 3.4 ± 1.3 min, and there were no episodes of bleeding or thrombosis. The ureter complication rate was 7.3%. Kidneys transplanted after 5 h of cold storage using the new technique yielded better postoperative creatinine results than similar preserved kidneys transplanted using previously described methods. We suggest this technique for studies of long- and short-term kidney preservation and transplantation in the rabbit, as well as for veterinary transplantation in which donor kidneys must be stored for only a short time before use. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:369,373 2003 [source]

    One technique, two approaches, and results: Thoracic duct cannulation in small laboratory animals

    MICROSURGERY, Issue 3 2003
    Mihai Ionac M.D., Ph.D.
    Experimental studies in immunology, pharmacology, or hematology require the sampling of the total thoracic duct lymph in awake and unrestrained rats or mice. Several approaches have been described for cannulation of the thoracic duct, but they are characterized by a modest reproducibility and a low lymph flow rate. An improved technique for obtaining thoracic duct lymph is described here, emphasizing the similarities and differences concerning both rats and mice (average weights of 305 and 15 g, respectively). Rats yielded a mean of 55.6 ml/day thoracic duct lymph, while lymph output in mice reached unexpected volumes of 29.3 ml/day. The use of an operating microscope and silicone cannula, and maintenance of mobility of the animals during lymph collection, offer a reliable method for a high and constant output of thoracic duct lymph. Relevant aspects of the murine thoracic duct anatomy are also identified. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:239,245 2003 [source]

    Experimental model of heterotopic uterus transplantation in the laboratory rat

    MICROSURGERY, Issue 3 2003
    Lucian P. Jiga M.D.
    The present study describes a standardized experimental model of whole-uterus-and-ovaries heterotopic allotransplantation in the laboratory rat. Fifteen transplantation procedures were done. The anatomy of the pelvic region was studied with an additional 20 dissections, noting the topographical and vascular anatomy of the uterus, fallopian tubes, and ovarian vessels. Recipients were randomized into three groups. The average operative time was 150 min. The postoperative survival rate was 100%. Postoperative vascular anastomosis patency was 100%, and 26% at 72 hr. Recipients were euthanized at 24 hr (group I), 48 hr (group II), and 72 hr (group III); grafts were harvested and examined macroscopically, and fixed in formaline for histopathological and immunocytochemical analysis. Failure in 74% of the grafts at 72 hr was due to early thrombosis, starting from the capillary bed and progressing towards the main feeding pedicles. More studies must be undertaken to further understand the rejection mechanisms in transplanted reproductive organs. The efficiency, feasibility, and safety for such an operation in humans remain to be proven. We consider the present model a suitable tool to study all the above-mentioned goals. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:246,250 2003 [source]

    Free osteocutaneous lateral arm flap: Anatomy and clinical applications

    MICROSURGERY, Issue 2 2003
    Franz Haas M.D.
    For many surgeons, the potential to reconstruct skin, fascia, tendon, or bone in a single-stage procedure has made the lateral arm flap the technique of choice for reconstruction of complex defects. The aim of this study was to examine more closely how the humeral bone is supplied by the posterior collateral radial artery. To this end, we dissected 30 cadaver arms to determine the vascular relationship of the lateral arm flap to the humerus. The number of directly supplying vessels, and height to the lateral epicondyle of the humerus, were examined. The reconstructive potential of the osteocutaneous flap in different indications is analyzed in a series of five clinical cases. In all dissected extremities, we found one or two branches of the posterior collateral artery directly and constantly supplying the bone between 2,7 cm proximal to the lateral epicondyle. In five cases, combined defects, including bone, were successfully reconstructed with lateral arm flaps, including vascularized bone. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:87,95 2003 [source]

    Development and validation of new model for microvascular transplantation of epiphyseal plate allografts with minimal adjoining epiphyseal and metaphyseal bone

    MICROSURGERY, Issue 2 2003
    M.Sc., Peter W. Bray M.D.
    A model for the free allograft microvascular transplantation of rabbit proximal tibial epiphyseal plate allografts was developed, validated, and tested in an in vivo animal model. Transplants contained the minimum amount of adjacent epiphyseal and metaphyseal bone compatible with preservation of the epiphyseal-plate vascular supply, as determined by corrosion casting. Perfusion to this graft was evaluated quantitatively using radioactive microspheres, and qualitatively using India-ink injection. Female New Zealand White rabbits at 12 weeks of age were utilized. Vascularized transplantation of epiphyseal plate allografts was performed either into a defect of matched size in the iliac crest or into a soft-tissue pocket without bone contact. Cyclosporine A immunosuppression (CSA) was administered daily for 6 weeks. Two control groups underwent identical surgical procedures, but had no postoperative immunosuppression. Epiphyseal plates both with and without bone contact, in rabbits immunosuppressed postoperatively with CSA, demonstrated longitudinal growth and preserved viability as determined by positive bromodeoxyuridine uptake. Control epiphyseal plates transferred without postoperative immunosuppression were uniformly nonviable. This new model has value as a basis for further studies into the clinical applicability of isolated epiphyseal-plate transplants. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:153,163 2003 [source]

    New model for simultaneous heart and kidney transplantation in mice

    MICROSURGERY, Issue 2 2003
    Minghui Wang M.D.
    In clinical settings, combined heart and kidney transplantation results in a lower incidence of cardiac graft and renal graft rejection as compared to isolated heart and kidney transplantation. To study the phenomenon in an experimental setting, we developed a model of combined heart and kidney transplantation in mice. According to our technique, we kept the patch of the infrarenal aorta and inferior vena cava (IVC) as long as possible during the donor's kidney explantation, and then, after finishing the kidney implantation with conventional techniques, we anastomosed the innominate artery and pulmonary artery of the heart graft to the patch of the infrarenal aorta and IVC of the renal graft, respectively, instead of the recipient's aorta and IVC. With the use of our method, combined heart and kidney transplantation in mice can be performed to get enough suture room for the second graft, to avoid prolonging the occlusion time of the recipient's circulation, and to profoundly decrease postoperative complications such as paraplegia and mortality. Of the 14 recipients with combined heart-kidney isografting, 10 have been successful (71.4%), surviving over 100 days with normal function of both grafts, and with lack of change in histological appearance. This suggests that the technique is feasible and reliable. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:164,168 2003 [source]

    Recovery of touch after median nerve lesion and subsequent repair

    MICROSURGERY, Issue 1 2003
    M.F. Meek M.D., Ph.D.
    Many techniques have been developed for the evaluation of peripheral nerve function. Consequently, physicians use different techniques in the clinic. This study describes the evaluation of touch after median nerve lesions in the forearm and repair. In order to evaluate touch, 25 patients, aged 11,51 years (mean, 29 years), were evaluated 3,10.5 years (mean, 5 years) after median nerve repair. The evaluation included the moving two-point discrimination test and Semmes-Weinstein monofilaments. We showed that 32% good,excellent results can be obtained with difficult nerve lesions. The results could have been improved if a sensory reeducation regime had been applied. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:2,5 2003 [source]

    Incidence and significance of microscopic pathological lesions found in pedicle and recipient vessels used in microsurgical breast reconstruction

    MICROSURGERY, Issue 1 2003
    H.H. El-Mrakby M.D.
    The purpose of this study was to assess the incidence of abnormal vascular histology and to determine whether or not this was correlated with the incidence of postoperative microvascular problems. The microvascular histology of both donor and recipient vessels was studied in 38 patients (40 flaps) undergoing breast reconstruction with free TRAM flaps. Preoperative risk factors were assessed and correlated with histological changes in vessels, and both were tested against anastomotic complications. Thrombosis of either the artery or the vein of the flap was seen in 6 cases (15%), and of these, two flaps failed completely and one suffered partial necrosis. The occlusion affected the arterial anastomosis in 3 patients, and the venous anastomosis in 2 patients, while both the artery and the vein were thrombosed in one case. Preoperative risk factors such as smoking, obesity, radiotherapy, and chemotherapy were not associated with a significantly higher incidence of thrombosis or with significant histological abnormalities in vessels (P value varied between 0.3,0.06). Microvascular histology showed variable degrees of pathological changes in six flaps (15%); nevertheless, in this group, only one flap suffered a venous thrombosis, which ended in total flap loss. Among those with one or more risk factors (24 patients), only 2 had some evidence of histological abnormality of the blood vessels used for the microvascular anastomosis (P = 0.2). © 2003 Wiley-Liss, Inc. MICROSURGERY 23:6,9 2003 [source]

    Inside-out vein graft and inside-out artery graft in rat sciatic nerve repair

    MICROSURGERY, Issue 1 2003
    Alécio Santos Barcelos Ph.D.
    Although veins and arteries present similar wall structures, there are differences which may be relevant in peripheral nerve reconstruction. Inside-out vein grafts (IOVG) have been satisfactorily used to repair both motor and sensitive nerves. However, the inside-out artery graft (IOAG) is a new technique and not fully investigated. Our study presents comparative morphological data on nerve regeneration achieved with IOVG and IOAG in the repair of Wistar rat sciatic nerves. Jugular veins and aorta arteries were harvested from donor animals and used "inside-out" to bridge a 10-mm gap. Animals were sacrificed at 10 weeks to evaluate nerve regeneration. Both techniques presented great variability in nervous tissue, though some animals showed satisfactory results. Different intensities of scarring processes might have interfered with nerve regeneration. Although IOVG and IOAG techniques showed similar morphometric results, in general, IOVG presented a closer-to-normal nerve organization than IOAG. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:66,71 2003 [source]

    Tissue engineering of peripheral nerves: Epineurial grafts with application of cultured Schwann cells

    MICROSURGERY, Issue 1 2003
    H. Fansa M.D., Ph.D.
    After a simple nerve lesion, primary microsurgical suture is the treatment of choice. A nerve gap has to be bridged, with a nerve graft sacrificing a functioning nerve. Alternatively, tissue engineering of nerve grafts has become a subject of experimental research. It is evident that nerve regeneration requires not only an autologous, allogenous, or biodegradable scaffold, but additional interactions with regeneration-promoting Schwann cells. In this study, we compared epineurial and acellularized epineurial tubes with and without application of cultured Schwann cells as alternative grafts in a rat sciatic nerve model. Autologous nerve grafts served as controls. Evaluation was performed after 6 weeks; afterwards, sections of the graft and distal nerve were harvested for histological and morphometrical analysis. Compared to controls, all groups showed a significantly lower number of axons, less well-shaped remyelinizated axons, and a delay in clinical recovery (e.g., toe spread). The presented technique with application of Schwann cells into epineurial tubes did not offer any major advantages for nerve regeneration. Thus, in this applied model, neither the implantation of untreated nor the implantation of acellularized epineurial tubes with cultured Schwann cells to bridge nerve defects was capable of presenting a serious alternative to the present gold standard of conventional nerve grafts for bridging nerve defects in this model. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:72,77 2003 [source]

    Dextrans in microsurgery: A review,

    MICROSURGERY, Issue 1 2003
    M.B. Ch.B. (Hons.), M.R.C.S. (Eng.), N. Jallali B.Sc.
    This articles reviews the use of dextrans in free tissue transfer. Current recommended regimes, indications, and complications are discussed. In conclusion, dextrans cannot be used as a substitute for good surgical technique, and should be utilized cautiously, especially in the elderly. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:78,80 2003 [source]

    Design of a new suture practice card for microsurgical training

    MICROSURGERY, Issue 8 2002
    Jesús Usón D.V.M., Ph.D.
    Suturing technique is of paramount importance in microsurgery. Basic training in this technique can be done using the practice card, a purpose-made polyurethane card. A practice card has been designed in the Minimally Invasive Surgery Centre to closely resemble microsurgical requirements in order to practice and learn correct microsuturing maneuvers. This practice card is a key part of microsurgical training. After many years of experience, and based on a survey we conducted, we can conclude that this practice card is essential for step-by-step microsurgical training. Using this card, the number of animals required to attain necessary microsurgical skills is reduced significantly. Furthermore, costs are also reduced, and the trainee can avoid mistakes during training with live animals, thus optimizing results. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:324,328 2002 [source]

    Effect of nondepleting anti-CD4 monoclonal antibody (Rib 5/2) plus donor antigen pretreatment in peripheral nerve allotransplantation

    MICROSURGERY, Issue 8 2002
    Vaishali B. Doolabh M.D.
    Peripheral nerve allotransplantation allows the reconstruction of injuries with long nerve gaps that are otherwise unsalvageable. In this study, the efficacy of anti-CD4 monoclonal antibody (mAb) combined with donor antigen pretreatment in prolonging the survival of short peripheral nerve allografts was investigated in a rodent model. Such an approach could potentially avoid the need for systemic immunosuppression and its concomitant morbidities. Buffalo rats received either nerve isografts or nerve allografts from Lewis rats. Untreated isograft and allograft groups were used as controls. Allograft recipients received either a single dose of RIB 5/2, a nondepleting anti-CD4 mAb, a single dose of Lewis splenocytes, or both antigen and RIB 5/2, 7 days prior to transplantation. Flow cytometric analysis verified that the T-lymphocyte population was maintained, while CD4 expression was downregulated by RIB 5/2. Histologic evaluation demonstrated better regeneration in the allograft recipients receiving both donor antigen and antibody, compared to recipients of untreated allografts or treatment with antigen or antibody alone. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:329,334 2002 [source]

    Management of flaps with compromised venous outflow in head and neck microsurgical reconstruction

    MICROSURGERY, Issue 8 2002
    Tateki Kubo M.D.
    Microvascular tissue transfer has become an indispensable procedure for head and neck reconstruction. Although remarkable progress has been made technically, anastomosed vessel occlusion is still a serious complication. Even with technically skilled microsurgeons, anastomosed vessel occlusion occurs because the technique is not the sole prophylaxis against thrombosis in microsurgery. Therefore, to minimize the possibility of an unfavorable result in microsurgery, microsurgeons must be familiar with management options for a vascular compromised flap. Most investigators have agreed that venous obstruction occurs more often than arterial obstruction. Here, we reviewed the published literature on the salvage of venous compromised flaps from the viewpoints of surgical correction, including reanastomosis and catheter thrombectomy, and nonsurgical procedures, such as a medicinal leech, hyperbaric oxygen, and thrombolytic therapy. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:391,395 2002 [source]

    Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experience

    MICROSURGERY, Issue 7 2002
    C. Holm M.D.
    In a prospective, clinical study, the clinical utility of indocyanine green for intraoperative monitoring of free tissue transfer was evaluated. The study comprised 20 surgical patients undergoing elective microsurgical procedures. Indocyanine green angiography was performed intraoperatively, immediately after flap inset, and the operating team was blind to the fluoremetric findings. Thereafter, postoperative monitoring was done exclusively by clinical examination (color, temperature, time for recapillarization, and bleeding after puncture). Final outcome was compared with results of perioperative indocyanine (ICG)-imaging, and classified either as total flap loss, partial flap loss, or successful tissue transplantation. A total of 2 (10%) complications was recorded, and included one partial and one total flap loss. Both complications were detected by intraoperative ICG imaging. Another case of intraoperative subclinical arterial spasm at the place of microvascular anastomosis was revealed by dynamic ICG-videography. This flap did not develop postoperative complications. In conclusion, evaluation of perfusion by ICG imaging is feasible in all kinds of microsurgical flaps, irrespective of the type of tissue. Even though not meeting all the criteria of an ideal monitoring device, significant additional information can be obtained. In this study, cases with arterial spasm, venous congestion, and regional hypoperfusion were revealed by intraoperative ICG-videography. There was a strong correlation between intraoperative findings and clinical outcome. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:278,287 2002 [source]

    Effect of long-term application of epinephrine on rat skin vasculature: Experimental study

    MICROSURGERY, Issue 7 2002
    Ercan Karacao, lu M.D.
    As a potent vasoconstrictor, epinephrine is used ubiquitously in plastic surgery. It is typically delivered subcutaneously in very low concentrations over a brief time interval. We are aware of no reports describing the long-term release of epinephrine as an independent agent to the soft tissues for the purpose of causing prolonged local vasoconstriction. This study was designed to address two goals: first, to investigate the effect of long-term local release of epinephrine from a drug delivery system on rat abdominal skin vasculature; secondly, to evaluate the pharmacological properties of this drug delivery system (DDS). Thirty male Sprague-Dawley rats, weighing 300,400 g, were included in the study. Animals were subdivided into two groups of 15 each. Group A (control group) and Group B (experimental group) were treated with saline and epinephrine-loaded microspheres (msps), respectively. The manufacturing process and formulation studies of the DDS are described. In vivo assays revealed a 7-day sustained release of epinephrine. After 7 days, neither residual nor supraphysiologic release of epinephrine was shown with high-performance liquid chromatography (HPLC). Histological studies with hematoxylin-eosin and periodic acid Schiff revealed a statistically significant increase in number of vessels as well as their diameter and wall thickness (P <0.05). Epinephrine release via this msp/DDS predictably induces local vasoconstriction over a time sequence known to be optimally associated with hypoxia and promotion of vascular augmentation. This model can be valuable in sustaining hemostasis during long-lasting (more than a few hours) surgical procedures by its long-acting vasoconstructive effect. The system's ability to intentionally cause vascular augmentation also bodes great potential in flap and graft surgery. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:288,294 2002 [source]

    Acute remote ischemic preconditioning on a rat cremasteric muscle flap model

    MICROSURGERY, Issue 6 2002
    Markus V. Küntscher M.D.
    A previous study showed, in a rat adipocutaneous flap model, that acute ischemic preconditioning (IP) can be achieved not only by preclamping of the flap pedicle, but also by a brief extremity ischemia prior to flap ischemia. The purpose of this study was to determine whether remote IP is also effective in other tissues such as muscle flaps. Twenty male Wistar rats were divided into three experimental groups. The rat cremaster flap in vivo microscopy model was used for assessment of ischemia/reperfusion injury. In the control group (CG, n = 8), a 2-hr flap ischemia was induced after preparation of the cremaster muscle. In the "classic" IP group (cIP, n = 6), a brief flap ischemia of 10 min was induced by preclamping the pedicle, followed by 30 min of reperfusion. A 10-min ischemia of the contralateral hindlimb was induced in the remote IP group (rIP, n = 6). The limb was then reperfused for 30 min. Flap ischemia and the further experiment were performed as in the CG. In vivo microscopy was performed after 1 hr of flap reperfusion in each animal. A significantly higher red blood cell velocity in the first-order arterioles and capillaries, a higher capillary flow, and a decreased number of leukocytes adhering to the endothelium of the postcapillary venules were observed in both preconditioned groups by comparison to the control group (P < 0.05). The differences within the preconditioned groups were not significant for these parameters. Our data show that ischemic preconditioning and improvement of flap microcirculation can be achieved not only by preclamping of the flap pedicle, but also by induction of an ischemia/reperfusion event in a body area distant from the flap prior to elevation. These findings indicate that remote IP is a systemic phenomenon, leading to an enhancement of flap survival. Our data suggest that remote IP could be performed simultaneously with flap elevation in the clinical setting without prolongation of the operation and without invasive means. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:221,226 2002 [source]

    Acute remote ischemic preconditioning II: The role of nitric oxide

    MICROSURGERY, Issue 6 2002
    Markus V. Küntscher M.D.
    The purpose of this study was to determine whether nitric oxide (NO) plays a role in the mechanism of acute "classic" as well as acute remote ischemic preconditioning (IP). Thirty-two male Wistar rats were divided into five experimental groups. The rat cremaster flap in vivo microscopy model was used for assessment of ischemia/reperfusion injury. In the control group (CG, n = 8), a 2-hr flap ischemia was induced after preparation of the cremaster muscle. The animals of group NO (n = 6) received 500 nmol/kg of the NO-donor spermine/nitric oxide complex (Sper/NO) intravenously 30 min prior to ischemia. The group LN + P (L-NAME + preclamping, n = 6) received 10 mg/kg N,-nitro-L-arginine methyl ester (L-NAME) intravenously before preclamping of the flap pedicle (10-min cycle length, 30-min reperfusion). L-NAME (10 mg/kg) was administered in group LN + T (L-NAME + tourniquet, n = 6) before ischemia of the right hindlimb was induced, using a tourniquet for 10 min after flap elevation. The limb was then reperfused for 30 min. Thereafter, flap ischemia was induced in each group as in group CG. In vivo microscopy was performed after 1 hr of flap reperfusion in each animal. Group NO demonstrated a significantly higher red blood cell velocity (RBV) in the first-order arterioles and capillaries, a higher capillary flow, and a decreased number of leukocytes adhering to the endothelium (stickers) of the postcapillary venules by comparison to all other groups (P < 0.05). The average capillary RBV and capillary flow were still higher in the CG than in the groups receiving L-NAME (P < 0.05). The data show that NO plays an important role in the mechanism of both acute "classic" as well as acute remote IP, since the administration of a NO-donor previous to ischemia simulates the effect of IP, whereas the nonspecific blocking of NO synthesis by L-NAME abolishes the protective effect of flap preconditioning. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:227-231 2002 [source]

    Lining the mouth floor with prelaminated fascio-mucosal free flaps: Clinical experience

    MICROSURGERY, Issue 5 2002
    D.D.S., L. Chiarini M.D.
    Soft-tissue defects of the mouth floor need thin, foldable, and pliable tissues able to preserve local anatomy as well as chewing, phonation, and deglutition. The oral mucosa is made of a stratified, nonkeratinized, epithelium-secreting mucus, which lubricates the oral cavity and facilitates tongue movements. No flap exists that can reproduce the physiology of the oral mucosa better than the oral mucosa itself. Prefabrication of mucosal flaps may represent the best solution. Therefore, 10 consecutive cases of mouth floor cancer were treated with prelamination of the fascia antibrachialis with mucosal grafts obtained from the healthy cheek, and with subsequent transplantation 3 weeks later. A significant increase in mucosal graft surface was seen in all cases, with a mean size twice the original. All flaps healed uneventfully. Follow-up time ranged between 2,60 months (average, 26.6 months). Morphological and functional results were excellent. Tongue motility, speech intelligibility, and swallowing were reestablished in all treated cases. Mucosal prelamination of the forearm fascia is feasible and allows physiological reconstruction of oral cavity defects up to 6 × 4 cm. © 2002 Wiley Liss, Inc. MICROSURGERY 22:177,186 2002 [source]

    Lower limb replantations: Indications and a new scoring system

    MICROSURGERY, Issue 5 2002
    Bruno Battiston M.D.
    The need for reconstruction of lower limb amputations is increasing, due to high-energy trauma in road accidents and work-related injuries. The indication for lower limb replantation is still controversial. Compared with upper limb replantations, indications are more select due to the frequent complications in lower limb salvage procedures, such as severe general complications or local complications such as necrosis, infections, nonunions, the need for secondary lengthening, or other reconstructive procedures. The satisfactory results given by artificial prosthesis, such as quicker recovery time and fewer secondary procedures, also contribute to the higher degree of selection for lower limb replantation candidates. Since 1993, we have replanted 14 amputations of the lower limb in 12 patients, including 2 bilateral cases. Although survival of the replanted segment was obtained in all patients, 5 cases were subsequently amputated for severe secondary complications. Of the remaining 9 cases, evaluated by means of Chen criteria, 7 had good results (3 Chen I and 4 Chen II), 1 sufficient (Chen III), and 1 poor (Chen IV). The best results were obtained in young patients. Our experience led us to examine the necessity for careful, objective patient selection. We developed a score evaluation system by modifying the international classifying method for severe limb traumas (mangled extremity severity score, or MESS system). This relatively simple system, based on the retrospective study of our cases, considers several parameters (patient's age, general conditions, level and type of lesion, time of injury, and associated lesions), giving each one a score. The total score gives the indication for replantation, predicts the functional outcome, and facilitates decision-making. © 2002 Wiley Liss, Inc. MICROSURGERY 22:187,192 2002 [source]

    Fabricating autologous tissue to engineer artificial nerve

    MICROSURGERY, Issue 4 2002
    Biao Cheng M.D.
    This study reports on the successful fabrication of artificial nerves with tissue engineering methods. Schwann cells were cultured for 2 weeks, seeded on polyglactin 910 scaffolds, and biomembrane-coated with rat-tail glue and laminin. Observation of the scaffolds' adsorptivity to Schwann cells, and of the growth and migration of Schwann cells, was made using a light microscope, and by scanning and transmission electron microscopy. The Schwann cells were able to migrate and proliferate on the polyglactin 910 fiber. Schwann cells were well-distributed, and formed a Büngner band on which the Schwann cells produced more matrices. Schwann cells on the biomembrane also grew well. We investigated the role of the tissue engineering conduit guide in vivo, using an established rabbit peripheral nerve regeneration model. At 8 weeks, axonal regeneration was observed in the distal nerve stump. Adult Schwann cells can be produced on the coated fiber and the biomembrane. Three-dimensional scaffolds with Schwann cells had the basic characteristics of the artificial nerve. These findings will provide a practical method for fabricating tissue-engineered artificial nerve to repair long nerve defects. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:133,137 2002 [source]

    Nerve regeneration through a healthy peripheral nerve trunk as a nerve conduit: A preliminary study of a new concept in peripheral nerve surgery

    MICROSURGERY, Issue 4 2002
    Fuat Yüksel M.D.
    The popularity of nerve conduits has increased recently due to the need for alternative nerve reconstruction techniques, obviating the harvest of nerve grafts. Based on ideas suggesting nerve tissue itself, which was the most physiologic environment for nerve regeneration, a study using 40 sciatic nerves of 20 rats was performed. The proximal stumps of transected peroneal nerves were sutured to the lateral wall of healthy tibial nerve trunks after removal of the epineurium. Twelve weeks later, tissue samples were taken from the anastomosis sites and from the levels above and below these sites. Configurations of fascicles were evaluated, and numbers of fibers were estimated. It was observed that the fibers of peroneal nerves regenerated into and through the tibial nerve trunk distally. This suggested that active regenerating fibers of a proximal stump of a nerve could regenerate and progress as a fascicular unit in optimum condition at the trunk of another healthy nerve. This preliminary study should stimulate further studies based on this new concept: that a nerve trunk can serve as the host for the regenerating fibers of another nerve. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:138,143 2002 [source]

    Combined cuff and suture technique for orthotopic whole intestinal transplantation in rats

    MICROSURGERY, Issue 3 2002
    Atsunori Nakao M.D.
    For the purpose of immunological study on small intestinal transplantation (SIT), rat SIT models using direct suture technique widely have been used, which requires at least several months of training for microsurgery. Alternatively, a simple cuff technique for SIT has been mainly used by us, which reduces warm-ischemic time and the training period, but the entire intestinal grafts usually obtain a limited blood supply. This report describes a modification of a combined cuff and suture technique for rat SIT to aid beginning microsurgical transplantation researchers. The advantages are 1) use of only arterial suturing, making it easier for beginners, with the cuff technique applied to the more difficult vein anastomosis; 2) achievement of better arterial inflow and graft survival than when the arterial cuff technique is used; and 3) doing only partial clamping of the aorta, which improves animal survival and success of the procedure. A very high successful rate in orthotopic whole SIT was achieved even by beginners. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:85,90 2002 [source]