Reconstruction with irradiated homograft costal cartilage

The authors present their experience with 51 patients who underwent 55 reconstructive and cosmetic operative procedures with irradiated homograft costal cartilage, who were studied between August of 1988 and June of 2001. The procedures included 52 rhinoplasties and three penile implantations among a total of 130 grafts. Follow-up ranged from 7 months to 12 years. There were two immediate graft exposure complications. Late complications included displacement of the graft in two patients, fracture of the graft in one patient, and partial resorption in one patient at 6 months postoperatively. The experience is described and the literature is reviewed.     

Reconstructing Tumour Defects: Lyophilised, Irradiated Bone Allografts

Tumour excision leaves behind large defects. Allografts provide an excellent alternative to autografts without donor site morbidity and are especially useful in large defects or in children where the quantity of available autograft is limited. In this paper we discuss our experience with indigenously procured and processed lyophilised, irradiated bone allografts. Bone allografts were used in 41 patients. They were used morsellised and used in 32 cases. Of these, 25 cases were available for follow-up. These included 21 patients in whom the allograft was used in contained cavities. Complete incorporation of the graft was seen between 6 and 9 months in all these 21 patients. In 4 patients the allograft was layered onto autograft. In only one of these the allograft incorporated with the host bone. Struts were used in 9 cases (3 cases complete intercalary segmental defect, 3 cases of hemicortical defects, 2 cases of allograft-prosthesis composite around the hip, in 1 case an iliac-crest block was used to stop bleeding from an anterior sacral defect). Of these, 2 full segment struts showed no incorporation. Both these patients were on chemotherapy and radiotherapy. There was no follow-up in sacral defect case. All the other struts incorporated with the host bone within 6-9 months.In 5 cases there was sterile postoperative drainage. All these cases went on to uneventful. Deep infection was observed in 4 patients (10%). In one, the graft was removed, another settled uneventfully with subsequent incorporation of graft, and two have a persisting sinus but good incorporation.To restore part of the strength of the struts it was necessary to hydrate them for 30 min prior to use. Autogenous marrow or autograft was used to provide osteoinductive properties.Conclusion. In selected cases the lyophilised, irradiated bone allografts proved to be very useful in reconstruction of large tumour defects.     

Augmentation of the atrophic mandible with a vascularized rib graft

A patient with a 29-year history of denture wearing had her mandible augmented with a vascularized rib graft. The rib was contoured to fit the arch of the mandible and vascularized by means of the facial arteries to the intercostal vessels. The nutrient artery was not included in the vascularized bone graft. Cortical cancellous bone chips were packed around the rib to augment the buccal surface of the rib graft. Periosteal perfusion and vascularity of the transferred rib were well documented at 1 week, 1 month, and 6 months postoperatively by radionuclide scintigraphy. It is now 24 months after surgery and the patient began wearing a denture 2 months after the rib transfer. She underwent a split-thickness skin graft vestibuloplasty and floor-of-the-mouth lowering 12 months following the rib transfer with improvement in her denture-wearing capabilities, which has remained constant for 10 months. Vertical resorption of the graft at 3 months was 10 percent, at 6 months 15 percent, and it has stabilized at 25 percent.     

The Use of Irradiated Allografts in Reconstruction of Tumor Defects – the Tata Memorial Hospital Experience

A Tissue Bank is a valuable adjunct to tumour management. In bone tumours, the defects produced by ablative surgery can be reconstructed using banked tissue, thereby obviating the donor site morbidity associated with autografts. Allografts are especially useful in large defects or in children where the quantity of available autograft is limited. The use of bone allografts in India has been limited by the availability of good quality, affordable grafts. In this article we share our experience with the use of indigenously produced allografts in limb salvage, as bone graft expanders and as struts. Lyophilised, irradiated bone allografts were morcellised and used in 32 patients. In 21 of these patients the allograft was used in contained cavities. Complete incorporation of the graft was seen between 6-9 months in all the 25 cases available for follow-up. In 4 patients the allograft was layered onto autograft. The allograft incorporated with the host bone in only one of these patients.Struts were used in 9 cases (3 cases complete intercalary segmental defect, 3 cases of hemicortical defects, 2 cases of allograft-prosthesis composite around the hip, 1 case an iliac-crest block was used to stop bleeding from an anterior sacral defect). Of these, no incorporation of the full segment struts was observed in 2 patients who were on chemotherapy and radiotherapy. The sacral defect case was lost to follow-up. All the other struts incorporated with the host bone within 6-9 months. In 5 cases there was sterile postoperative drainage. Overall infection was observed in 4 patients (10%). In one the graft was removed, another settled uneventfully with subsequent incorporation of graft, and two have a persisting sinus but good incorporation. Since radiation and lyophilisation are known to affect the material properties of bone, the grafts were rehydrated in saline for 30 minutes prior to transplantation. Autogenous marrow or autograft was used to provide osteoinductive properties. In selected cases the lyophilised, irradiated bone allografts proved to be clinically useful in the reconstruction of large tumour defects.     

Quality of life and disease-specific functional status following microvascular reconstruction for advanced (T3 and T4) oropharyngeal cancers

In an effort to evaluate quality-of-life benefits of ablative head and neck cancer surgery and microvascular reconstruction, a longitudinal study was undertaken in which patients with T3 or T4 oropharyngeal cancers without systemic metastases at presentation were administered both general and disease-specific quality-of-life instruments preoperatively and postoperatively. In an initial prospective pilot study, 17 cancer patients were evaluated both preoperatively and postoperatively using the Medical Outcomes Short-Form Health Survey questionnaire (SF-36) and the Performance Status Scale for Head and Neck Cancer Patients. In the second part of the study, the need was recognized for a different disease-specific measure, for more frequent intervals of longitudinal follow-up (rather than be limited by a single data collection point), and for a noncancer control group. Since then, 17 more cancer patients were evaluated in the second part of the study and were compared with patients who had similar reconstructions after suffering head and neck trauma and also with age-matched controls. Instead of the performance status scale, the University of Washington Head and Neck Quality of Life questionnaire was substituted. Interval assessments were done at 1, 3, 6, and 12 months and preoperatively. Whereas many of the general and disease-specific quality of life subclasses initially worsened following extensive surgery and radiation therapy, most returned to the preoperative baseline by 6 months following conclusion of treatment and surpassed pretreatment values at 1 year. It can be concluded, based on this study, that large resections and reconstructions for head and neck cancer patients are justified in terms of outcome; the resection controls the local disease, and the microvascular reconstruction restores quality of life and functional status.     

Long-term remodeling of vascularized and nonvascularized onlay bone grafts: a macroscopic and microscopic analysis

The present study was performed to compare vascularized and nonvascularized onlay bone grafts to investigate the potential effect of graft-to-recipient bed orientation on long-term bone remodeling and changes in thickness and microarchitectural patterns of remodeling within the bone grafts. In two groups of 10 rabbits each, bone grafts were raised bilaterally from the supraorbital processes and placed subperiosteally on the zygomatic arch. The bone grafts were oriented parallel to the zygomatic arch on one side and perpendicular to the arch on the contralateral side. In the first group, vascularized bone grafts were transferred based on the auricularis anterior muscle, and in the second group nonvascularized bone grafts were transferred. Fluorochrome markers were injected during the last 3 months of animal survival, and animals were killed either 6 or 12 months postoperatively. The nonvascularized augmented zygoma showed no significant change in thickness 6 months after bone graft placement and a significant decrease in thickness 1 year after graft placement (p < 0.01). The vascularized augmented zygoma showed a slight but statistically significant decrease in thickness 6 months after graft placement (p < 0.003), with no significant difference relative to its initial thickness 1 year after graft placement. In animals killed 6 months after bone graft placement, both the rate of remodeling and the bone deposition rate measured during the last 3 months of survival were significantly higher in the vascularized bone grafts compared with their nonvascularized counterparts (p < 0.02). By 1 year postoperatively, there were no significant differences in thickness, mineral apposition rate, or osteon density between bone grafts oriented perpendicular and parallel to the zygomatic arch. These findings indicate that the vascularity of a bone graft has a significant effect on long-term thickness and histomorphometric parameters of bone remodeling, whereas the direction of placement of a subperiosteal graft relative to the recipient bed has minimal effect on these parameters. In vascularized bone grafts, both bone remodeling and deposition are accelerated during the initial period following graft placement. Continued bone deposition renders vascularized grafts better suited for the long-term maintenance of thickness and contour relative to nonvascularized grafts.     

Q fever in maritime Canada.

Only nine cases of Q fever were recorded in Canada in the 20 years prior to 1978. In the 18 months from August 1979 to January 1981 the disease was diagnosed serologically in six patients from the Maritime provinces. All were epidemiologically unrelated and none had been exposed to animals. Five had pneumonia and one had chronic Q fever with probable prosthetic valve endocarditis. Three of the five pneumonia patients presented with signs and symptoms of an acute lower respiratory tract infection and were indistinguishable clinically from other patients with atypical pneumonias. The other two with pneumonia presented with nonresolving pulmonary infiltrates and complained of decreased energy. Four of the five pneumonia patients responded well to treatment with erythromycin; the fifth required two courses of tetracycline. The patient with chronic Q fever had a large amount of cryoglobulins in his serum and evidence of immune complex disease. These cases indicate that Q fever should be considered as a possible cause of atypical pneumonia in Canada.     

The use of photographs of postoperative results prior to melanoma resection

A total of 99 patients scheduled for resection of stage I melanoma were assigned randomly to be shown individually relevant photographs of anticipated postoperative results. All patients had received verbal information on this subject during discussions with their plastic surgeons. Anticipated and actual cosmetic impact or distress was measured with a self-report questionnaire given prior to and 6 months following surgery. Patients were least distressed postoperatively when their scars were not larger than anticipated. However, photographs failed to achieve the expected benefit of increasing the accuracy of patients' expectations of their postoperative appearance. Consequently, photographs had no effect on levels of preoperative or postoperative distress. Selective attention and preferences for limited information among some patients are suggested explanations for these results.     

Adjunctive treatment of congenital pigmented nevi with phenol chemical peel

The purpose of this study was a retrospective evaluation of the treatment of congenital pigmented nevi using the phenol chemical peel technique. Patients were treated with standard Baker formula in the operating room under general anesthesia or intravenous sedation with continuous electrocardiogram monitoring. A total of 20 patients were reviewed (13 girls and 7 boys, mean age 3.8 years). Eight patients had nevi located on the face, five patients had trunk lesions, and three patients had lesions on the thighs. Two patients had nevi located on both the face and the trunk, and two patients had involvement of the face, trunk, and thigh. Three of the above patients had the classic "bathing trunk" distribution of the nevi. A test area was peeled in four patients, and in five patients preoperative biopsies were performed to rule out malignancy before initiation of therapy. An average of 2.6 treatments were performed per patient. Two patients had adjunctive dermabrasion to increase the depth of peel and to contour surface irregularities. The length of follow-up ranged from 6 to 84 months with a mean of 28 months. Healing of the wounds occurred within 2 to 3 weeks postoperatively. Seventy-five percent of patients had satisfactory cosmetic improvement in the appearance of the lesions following treatment. Four patients had recurrence of the pigmentation after an initial lightening response, three of whom had their nevi subsequently excised. There was no incidence of hypertrophic scarring or cardiac and/or renal complications. There was one death from complications of leptomeningeal melanocytosis. Chemical peeling of congenital pigmented nevi is an acceptable alternative method of therapy for those lesions that are too large for excision and primary closure or for lesions in which excision would result in unacceptable scars in areas such as the face.     

DEXA对骨髓炎骨缺损治疗中骨痂密度的评价

目的：探讨DEXA对骨髓炎骨缺损治疗中骨痂密度的评价及意义。方法：严格按照纳入排除标准,选取21例骨髓炎清创后伴大段皮质骨缺损一期植骨的病人。术后4,6,8,10个月后对骨折端骨痂行双能X线骨密度仪检测,并进行X摄片以及Enneking评分,从而明确植骨区愈合骨痂的密度变化趋势,骨愈合情况以及症状改善情况。结果：（1）X线摄片结果显示：4个月后：骨缺损区依然清晰可见,内有少量稀疏骨痂通过,少量外骨痂形成。6个月后：植骨区内骨痂含量明显增多,且外骨痂膨大。8个月：缺损区模糊,有较致密骨痂生成,且外骨痂逐渐减少。10个月：植骨区骨痂更加致密,且部份髓腔再通。（2）Enneking评分：患者术后第10个月功能恢复情况评估正常功能20例,20分以下的患者1例。（3）BMD测定：骨折端的骨密度及骨密度比率随时间延长而增加,植骨10个月后患侧的骨密度已可基本上达到正常对照侧的骨密度水平。结论：双能X线骨密度测量从一定程度上反映出骨痂的力学强度特性。在感染性骨缺损治疗中可以作为检测植骨区的恢复情况的参考。     

Single-surgeon experience of 87 buccal mucosal graft harvests

Although buccal mucosa has been the preferred graft material for use in the reconstruction of anterior urethral strictures for approximately 20 years, the plastic surgery literature is lacking in studies describing and evaluating this technique. The authors sought to report their experience with the technique of buccal mucosa graft harvest for use in urethral reconstruction. The authors identified 87 consecutive patients who underwent buccal mucosal graft harvesting during a 15-year period from 1995 to 2010. All donor sites were closed primarily. Preoperatively, a specialty-specific evaluation was performed by plastic surgeons and urologists. Postoperative donor-site morbidity was followed clinically. Eighty-seven patients underwent buccal harvesting. A single buccal graft was harvested in 75 patients (86.2 percent) and bilateral grafts were harvested in 12 patients (13.8 percent). The median patient age of the patients was 42 years (range, 16 to 78 years). There were no major intraoperative or postoperative complications. Minor complications included mild discomfort, numbness, cheek swelling, and restriction of oral movement, all of which resolved by the 3-month postoperative visit. The ability to eat and drink postoperatively was diminished during only the first 24 to 48 hours in all patients. Our series provides a 1-year follow-up in a substantial cohort looking at clinical outcomes after buccal harvesting. These results confirm the safety and efficacy of buccal mucosal harvesting to provide an effective and cosmetically superior option for urethral reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.     

Psychological sequelae to elective sterilisation: a prospective study.

A total of 201 women were interviewed four weeks before elective interval tubal sterilisation, of whom 190 (94.5%) were assessed again six months postoperatively and 193 (96.0%) 18 months postoperatively. Before sterilisation the prevalence of psychiatric morbidity as measured by the present state examination was 10.4% (21 patients), no greater than might be expected in a general population sample; six months after the operation the prevalence was significantly reduced to 4.7% (nine patients); and 18 months postoperatively it had returned almost to the preoperative value (9.3%; 18 patients). Postoperative psychosexual disturbance was rare, only 3% of patients reporting reduced enjoyment of sexual intercourse at either follow-up. Considerable regret was reported by only five patients (2.6%) six months after the operation and by eight (4.1%) 18 months after the operation; however, some dissatisfaction was reported by 15 patients (7.9%) at six months and 21 patients (10.9%) at 18 months. Postoperative psychiatric disturbance and dissatisfaction were largely associated with preoperative psychiatric disturbance. Thus there was no evidence that elective interval sterilisation increased the risk of psychiatric disturbance up to 18 months after the operation.     

Bioactivation of free-fat transfers: a potential new approach to improving graft survival.

A new approach to free-fat autotransplantation resorption was evaluated experimentally in a rat animal model. Bioactive fat grafts were created by the addition of basic fibroblast growth factor delivered by dextran beads to the grafts and compared with free fat alone, free fat plus beads, and free fat plus beads and a control solution in the same animal. The grafts were assessed by weight and histology at 1 and 12 months postoperatively in 40 animals. A graded response in weight retention was observed at 1 and 12 months, with the growth factor-treated grafts exhibiting near complete weight maintenance after 1 year. All other bead-containing grafts had an intermediate response, with free fat alone averaging more than one-half graft weight loss after 1 year. Histologically, the bead-containing grafts had good fibroblastic ingrowth, but extensive intercellular collagen formation and the occurrence of small-sized adipocytes among the larger adipocytes were seen only in the growth factor-treated grafts. These findings indicate that graft manipulations that affect the preadipocyte cells of the graft or fibroblastic components of the recipient site, either through polypeptide stimulation or surface charge attraction, may offer a viable approach to postoperative fat-graft volume maintenance.     

Combined modality treatment of locally advanced oral and oropharyngeal cancer following primary radiotherapy with and without taxol radiosenzitization

AIM: To determine the effect of radiosensitization with Taxol and multimodality treatments on the survival of advanced oral and oropharyngeal cancer. Patients, methods: 56 patients with St. III-IV oral or oropharyngeal cancer were treated with external beam radiotherapy; 26 of them were sensitized by low-dose paxlitaxel and 30 were irradiated traditionally. The median follow up was 23 months (17-36). Endpoints of the study were: response to radiotherapy, progression-free and overall survival and the results of surgery and chemotherapy following radiation. RESULTS: 73.3% (41/56) of treatments resulted in CR or PR with median 10 months (0-33) progression-free and 14 months (4-33) overall survival. There was no significant difference between the radiosensitized and traditional radiotherapy group (p=0.6). The survival was significantly influenced by the stage of tumor and the response to primary radiotherapy. Seven (38.9%) of 16 patients treated also by either surgery or chemotherapy for recurrent or residual disease are free of cancer, 6 (35%) alive with tumor and 5 (26.1%) died with median survivals of 21, 20.5 and 18 months, respectively. Those treated only with radiotherapy with or without sensitization are free of cancer in 31.6%, alive with cancer 5.3%, died 63.2%. CONCLUSION: There were significant correlation between tumor stage, response to radiotherapy and combined modality treatment, and surival. The radiosensitizing effect of Taxol was not obvious so far, it may be apparent in the future by analyzing the long term survival data.     

The Warren Shunt in Treating Bleeding Esophageal Varices

In patients who have impaired hepatic reserve, the Warren shunt has been proposed as an effective operation because it decompresses the esophageal varices without disturbing portal perfusion of the liver. However, early reports of high operative mortality and technical difficulties have impeded acceptance of the procedure.The operation was done in a series of 17 patients. All patients in whom elective variceal decompression with a patent splenic vein was required and without clinical ascites were candidates for this operation. Follow-up ranged from 2 to 48 months. Six patients had alcoholic cirrhosis, two had primary biliary cirrhosis and seven had postnecrotic cirrhosis; in two the cause of the liver disease was unknown. Five patients were categorized as Child''s class A, nine as class B and three as class C. No intraoperative or early postoperative deaths owing to hemorrhage occurred. However, there was one death two weeks postoperatively from pulmonary sepsis and one death five weeks postoperatively due to antigen-positive hepatitis. Two patients died from hepatic failure six weeks and five months after operation, respectively; in the first of these, chronic active hepatitis was diagnosed at the time of operation. In one patient hemorrhage recurred and transfusion was required. Although ascites, which eventually resolved, developed in eight patients after operation, the results in 76 percent of patients have been good without new episodes of hemorrhage or encephalopathy. We conclude that the Warren shunt is a safe and effective elective operation for the treatment of patients in whom hemorrhage from esophageal varices has occurred.     

Simplified oesophageal transection for bleeding varices.

Thirty patients with bleeding oesophageal varices were treated by oesophageal transection using the SPTU gun. Any form of shunt was contraindicated in all the patients. Twelve operations were done as urgent procedures within 36 hours of haemorrhage. The overall operative mortality rate was 10%, and there were two late deaths during follow-up, which has so far extended from two months to two years. Three of the patients had recurrent bleeding, and residual varices were probably the source in two. There were no cases of portal systemic encephalopathy. Although the follow-up is too short to allow any definite conclusions, these early results suggest that oesophageal transection with the SPTU gun may be useful in the large proportion of patients in whom injection sclerotherapy, shunt surgery, or conservative treatment is inappropriate.     

Functional reconstruction using a depressor anguli oris musculocutaneous flap for large lower lip defects, especially for elderly patients

Described here is a new technique to reconstruct large lower lip defects using one or two musculocutaneous island flaps, which includes an innervated depressor anguli oris muscle and has a facial artery in its pedicle. Vermilion is simultaneously reconstructed using a mucosal transposition flap. Three patients who had a total lower lip defect and five patients who had a defect larger than one-half of the lower lip were treated by our procedure. All the flaps survived completely without any signs of vascular stasis. In six patients, sphincter function and sensation appeared within 3 months after surgery. In one patient who needed a total lower lip reconstruction, the depressor anguli oris muscle was atrophic and the motor nerve could not be found. This patient could not regain motion. One other patient complained of a sialorrhea accompanied by sensory loss; however, his sensation improved within 6 months after surgery. All of the reconstructed lower lips were large enough to enable the patient to wear dentures and were of a cosmetically acceptable appearance 1 year after surgery.     

Sequelae and support after termination of pregnancy for fetal malformation.

A retrospective study examined the reactions to the termination of pregnancy for fetal malformation and the follow up services that were available. Women resident in Mid Glamorgan who had had a termination between 1977 and 1981 because of positive findings after midtrimester prenatal diagnostic tests for neural tube defect or chromosome abnormalities were interviewed at home using a semistructured interview schedule. Three retrospective internal comparison groups were formed from those women who had also had a spontaneous abortion, previous stillbirth, or neonatal death or previous termination for medicosocial reasons early in pregnancy. Of the 48 women interviewed, 37 (77%) experienced an acute grief reaction after the index pregnancy was ended. This reaction was akin to that documented after stillbirth or neonatal death. Twenty two women (46%) remained symptomatic six months after the pregnancy had been ended, some requiring psychiatric support, compared with no such reaction after spontaneous abortion or termination for medicosocial reasons. All the women who had previously had a stillbirth or neonatal death were visited at home either by the general practitioner or by the midwife after that event but such follow up was limited to only eight of the study group after termination for fetal malformation. The findings suggest that support is inadequate for these patients and that improved follow up and counselling services may lessen the adverse sequelae of termination for fetal malformation.     

Outcomes Following Primary Anterior Cruciate Ligament Reconstruction Using a Partial Transphyseal (Over-the-Top) Technique in Skeletally Immature Patients

BackgroundThe incidence of anterior cruciate ligament (ACL) injuries in skeletally immature patients is increasing, with ACL reconstruction preferred in this population due to reported chondroprotective benefits. Due to concerns with growth disturbance following ACL reconstruction in skeletally immature patients, various physealsparing and partial transphyseal techniques have been developed. Currently, there is no consensus on the most effective ACL reconstruction technique in skeletally immature patients. The purpose of the current study was to report the outcomes of a partial-transphyseal over-the-top (OTT) ACL reconstruction in a cohort of skeletally immature patients.MethodsAll patients with radiographic evidence of open tibial and femoral physes that underwent primary ACL reconstruction using a partial-transphyseal OTT technique between 2009-2018 at a single tertiary-care institution with at least twelve months of clinical follow-up were retrospectively reviewed. Patient demographics, physical examination findings, graft ruptures, return to sport, and Tegner activity levels were analyzed. Statistical significance was defined as p<0.05.ResultsOverall, 11 males and 1 female (12 knees) with a mean age of 12.8±1.8 (range: 10-16) years were included in the study. The mean postoperative follow-up of the cohort was 2.3±1.2 (range: 1.1-5.2) years. All ACLs were reconstructed with hamstring autograft with allograft augmentation utilized in a single patient. There were two cases of ACL graft rupture (16.7%). All patients were able to return to the same or higher level of sporting activity at an average of 7.4+2.7 months. There were no cases of clinically significant longitudinal or angular growth disturbance.ConclusionPartial transphyseal ACL reconstruction using a transphyseal tibial tunnel and an extra-articular OTT technique on the femur in skeletally immature patients affords minimal risk of growth disturbance with a graft rupture rate consistent with what has been reported in this high-risk population. All patients were able to return to sport at the same or higher level. Level of Evidence: IV     

Coronary artery bypass with glycerol-preserved saphenous vein allografts

Over a 2-year period, 19 patients whose autologous saphenous veins were either unsuitable or unavailable underwent myocardial revascularization with saphenous vein allografts (SVAs) at our institution. All SVAs had been preserved in 98% glycerol at room temperature for at least 3 weeks (average, 7 weeks); before use, they were rinsed with saline and antibiotic solution. One operative death (5.2%) and three late deaths (16.6%) occurred. Fourteen of the long-term survivors have been observed for 24 to 48 months (average 32.2 months) postoperatively. Nine are asymptomatic, whereas four complain of angina, and one reports exertional dyspnea with-out chest pain. Only three patients have been restudied (7, 10, and 18 months after surgery, respectively); in each of these patients, angiography has shown occlusion of all SVAs. However, histologic examination of glycerol-preserved SVAs has not revealed pathologic changes that would suggest potential graft failure. Despite fairly satisfactory clinical results, preliminary hemodynamic data indicate that glycerol-preserved SVAs are unsuitable for myocardial revascularization in the absence of autologous saphenous veins.