摘要:

AbstractTwo hundred fifty‐two vascularized composite tissue transfers were performed from 1985 to 1992 at Nara Medical University Hospital. Free tissue transfers were performed in 185 patients and island tissue transfers in 67 patients. Of these, 39 flaps were reexplored because of vascular complications. On initial reexploration, vascular obstruction was found at the site of anastomosis or in the main vascular pedicle in 36 patients and in the perforating vessels to the monitor flap in three patients. Arterial thrombus occurred in 11 patients, venous thrombosis in 12, and both in nine. Twenty‐five reexplored flaps were salvaged. Initially, heparin was administered systemically when vascular compromise was suspected intraoperatively or postopera‐tively. Recently, we have used a „continuous local heparinization”︁ technique to minimize blood loss. This method has been used in 12 patients who underwent reexploration and in nine patients in whom vascular compromise was suspected. Nineteen flaps survived completely, and two flaps failed. © 1993 Wi

ISSN:0738-1085    

DOI:10.1002/micr.1920140802

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe use of an arteriovenous fistula (AVF) to afford vascular access for free tissue transfer is described in 11 consecutive patients from a 1 year period. The leg was the site of pathology in six cases, and a reversed saphenous AVF to the femoral vessels was created. In the remaining five cases, those in the head and neck and arm regions, the recipient vessels varied. The mean patient age was 37.7 years, and ten of 11 patients were male. Etiologies of defect were automobile accidents in six cases, neoplasm in three, and gunshot wound and electrical injury in one patient each. Mean ischemia time was 113 ± 15 min. Mean length of AVF was 27.3 ± 2.1 cm. All flaps survived. AVF was a useful technique in the current study. Several maneuvers were undertaken to minimize the risk of thrombosis. All patients were given aspirin prior to AVF creation. Patients received dextran 40 in the postanastomosis period for 5 days. Finally, every effort was made to create the AVF between large vessels, especially in the leg, to maximize blood flow. © 1993 Wiley‐Liss

ISSN:0738-1085    

DOI:10.1002/micr.1920140803

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA working knowledge of the venous anatomy is seldom emphasized but is an essential element in all microvascular procedures. The cephalic vein has been chosen here to serve as a model, since it is an important source for both afferent and efferent flow for flap transfers as well as in limb replantations. The better known, lower extremity superficial veins, especially as a source for long vein grafts, are not necessarily the best option. The cephalic vein represents the most versatile of the large superficial veins of the upper extremity and has numerous roles in microsurgery other than as a viable alternative for vein grafts. © 1993 Wiley‐Liss I

ISSN:0738-1085    

DOI:10.1002/micr.1920140804

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThis preliminary report describes the use of a rat model developed to study in vivo the effect of anesthesia, contusion, and cryotherapy on skeletal muscle microcirculation by use of an implanted chamber. The diameters of arterioles and venules within the chamber were determined by photomicroscopy in the contusion study and by compound videomicroscopy in the anesthesia study; microvascular perfusion was determined by laser Doppler fluxmetry (LDF). Combined ketamine and xylazine anesthesia significantly reduced (P<0.05) arteriolar and venular diameters by 32.4% and 37.8%, respectively, and average LDF measurements by 36.1%. Contusion significantly increased arteriolar diameters over baseline values (P<0.05); cryotherapy did not alter arteriolar diameters but increased venular diameters (P<0.05). It is hypothesized that this increase in venular diameter may, by increasing the surface area available for reabsorption, explain one mechanism by which cryotherapy decreases the edema of contusion. Use of this model should help to advance the understanding of microcirculatory dynamics following contusion and cryotherapy. © 1993 Wiley‐Liss I

ISSN:0738-1085    

DOI:10.1002/micr.1920140805

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractEndothelium‐derived relaxation mediated primarily by endothelium‐derived relaxing factor/nitric oxide (EDRF/NO) is essential in the maintenance of vascular tone. However, little is known about the effects of denervation on EDRF‐mediated relaxation in the microcirculation after reimplantation. Using intravital videomicroscopy in the rat cremaster model, this study assessed the effect of acute and chronic denervation of the muscle, produced by severing the genitofemoral nerve, on EDRF‐mediated vasorelaxation. The results demonstrated that acetylcholine‐induced EDRF relaxation (10−6M) significantly relieved norepinephrine‐induced vasoconstrtction in small arteries (40–80 (μm diameter) in both the acute and chronic denervated muscles. There was no significant difference in the relaxant response between the denervated or innervated controls in each group or between the acute or chronic groups. This relaxation was prevented by methylene blue (10−4M). These findings suggest that EDRF‐mediated relaxation in the microcirculation is not dependent on tissue innervation. Thus the use of potent endothelial dependent agonists may be of use in cases of vasospasm postreimplantation.

ISSN:0738-1085    

DOI:10.1002/micr.1920140806

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractDifferent processes of microvascular wound healing under hypertension in comparison to normotension have been suspected. To explore these differences at the site of anastomotic wound repair, we performed microvascular anastomoses of the femoral arteries in 12‐week‐old, stroke‐prone hypertensive rats (SHRSP) whose maximum blood pressure reached 238 mm Hg and in normotensive age‐matched Wistar Kyoto (WKY) rats. Morphologic changes under hypertension were examined via light microscopy. The arrangement and number of endothelial cells were examined using the en face silver staining technique. The plasma activity levels of factor XIII were also measured in each group. Transitional healing at the microvascular anastomosis site was evaluated via scanning electron microscopy. The extent of endothelial migration over the exposed media around the needle holes was determined using a computerized graphic analysis system. Histologic cross sections demonstrated a thickened media, with altered shape and arrangement of the smooth muscle cell nuclei in SHRSP arteries compared with WKY arteries. En face silver staining showed small and spindle‐shaped endothelial cells with an irregular cell arrangement and distribution in SHRSP arteries relative to WKY arteries. Factor XIII was increased 36% over baseline in SHRSP rats post‐operatively; this was significantly higher than the increase in WKY rats (P<0.05). Although both SHRSP and WKY arteries had similar wound healing responses to microvascular anastomosis, endothelial cell migration over the exposed media was significantly accelerated in the SHRSP rats. © 1993 Wi

ISSN:0738-1085    

DOI:10.1002/micr.1920140807

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractNerve regeneration using artificial biodegradable conduits is of increasing interest. The aim of this study is to evaluate the regeneration and maturation of a nerve after long‐term implantation (2 years) of a biodegradable poly‐L‐lactide/poly‐e‐caprolactone (PLLA/PCL) copolymeric nerve guide in the sciatic nerve of the rat. After harvesting, we evaluated both the regenerated nerves and the controls, using light microscopy, transmission electron microscopy, and morphometric techniques. Remnants of biomaterial were still present after 2 years of implantation, but the foreign body reaction was very mild at this stage, due to the rounded shapes of the polymer debris. Morphometric analysis showed significant differences between the regenerated nerve and the normal sciatic nerve: the number of myelinated fibers is higher, and the mean fiber diameter of the myelinated fibers in the regenerated nerve is smaller. In conclusion, the results demonstrate that the new PLLA/PCL nerve guide can provide optimal conditions for regeneration and maturation of damaged nerves. © 1993 Wile

ISSN:0738-1085    

DOI:10.1002/micr.1920140808

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIn 30 rabbits, both saphenous nerves were harvested as autografts and coapted to the branch for the rectus femoris muscle without connection to any distal target muscle. The graft from the right thigh was led to the contralateral extremity (crossover grafting). The graft on the left side remained on the same extremity (ipsilateral grafting). Animals were separated into four groups and were sacrificed 3, 6, 9, and 12 months after grafting. Specimens of the grafts and the donor motor branches were harvested for histomorphometric examination. The number of myelinated nerve fibers in the distal end of the nerve grafts was significantly increasing from 3 to 6 months after grafting and remained on a relatively constant level in the long‐term groups. Three months after the first operation, greater numbers of myelinated nerve fibers were counted after ipsilateral grafting than after crossover grafting. In the long‐term groups, this difference could not be observed. © 1993 Wiley‐Li

ISSN:0738-1085    

DOI:10.1002/micr.1920140809

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe effects of cyclosporine (CsA), a strong immunosuppressive drug, on vascularized allogeneic joint transplantations were examined. An orthotopical transplant model of a vascularized knee joint allograft was developed using inbred DA and Lewis rats to investigate the fate of grafts following withdrawal of short‐term immunosuppression compared to continuous immunosuppression with CsA. Five isograft controls acquired solid bone union at both femur and tibia sites within 4 weeks, and joint function as skeletal support was maintained until 25 weeks. Without immunosuppression, ten allografts were severely rejected within the first week, and joint destruction occurred immediately. Twenty‐five short‐term immunosuppressed rats acquired solid union, but, after withdrawal of immunosuppression, grafted joints showed gradual rejection and were destroyed due to pathological fractures or joint instability, although partial revascularization from the recipient occurred. Ten allografts under continuous immunosuppression at a dose of 10 mg/kg/day showed no rejection and remained viable for 12 weeks postoperatively, but thereafter all rats died. Death was considered to be a side effect of CsA. Fifteen animals, under continuous immunosuppression at a dose of 5 mg/kg/day, showed no rejection except in the bone marrow; the grafted joint function was not effected until 25 weeks. Continuous treatment with low and nontoxic doses (5 mg/kg/day) of CsA was necessary to maintain the functions of the grafted joint. © 1993 Wiley‐

ISSN:0738-1085    

DOI:10.1002/micr.1920140810

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractUW solution has been found to be an effective organ perfusate for transplantation. Initial studies in experimental pedicle skin flaps have also demonstrated its unique effectiveness in prolonged ischemia. To understand better the limits of its preservation properties without the influence of endothelial clamp damage, we have undertaken to study the properties of UW solution in experimental microvascular free flaps. Control, lactated Ringer's, and UW solutions were utilized in pedicle and microvascular free flaps in Sprague‐Dawley rats over varying periods of ischemia. UW solution demonstrated a clear superiority over all other solutions in both flap models. In addition there also was a significant prolongation of critical ischemia time in UW‐treated free flaps compared to pedicle flaps. © 1993 Wiley‐Li

ISSN:0738-1085    

DOI:10.1002/micr.1920140811

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY