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Biomedical subjects

William C Lineaweaver

Publications and source records attributed to William C Lineaweaver.

At least 19 recordsLinked to original sources
PubMed2007

Immediate and delayed use of arteriovenous fistulae in microsurgical flap procedures: a clinical series and review of published cases.

In microsurgical flap procedures, creation of an arteriovenous fistula (AVF) is a technique of vein grafting where the vein graft is connected to recipient vessels as a flow-through loop prior to harvest and inset of the flap. Controversy exists whether this technique can be used as a 2-stage procedure with the loop and flap transfer accomplished in sequential operations or if the loop and flap transfer should be performed in a single operation. We performed 12 consecutive 1-stage AVF-flap procedures, with 1 flap failure. We combined this series with previously published reports to compare outcomes of 1-stage and 2-stage procedures. We found no significant difference in flap outcomes or complication rates between the 2 strategies. We conclude from our experience and this analysis that single-stage AVF-flap procedures are the optimum application of this technique.

Adolescent↗
PubMed2006

Rejection.

Explore the source record for details and available documents.

Humans↗
PubMed2006

DNA degradation in nuclei of muscle cells followed by ischemic injury in a rabbit amputation model.

This study evaluated DNA degradation in nuclei of muscle cells during ischemia in a rabbit limb amputation model. Seven New Zealand rabbits were used. The left rear limb of the animal was amputated. The quadriceps femoris muscle was biopsied, as well as the rabbit carotid arteries. Half of the tissue samples were preserved at a cold temperature (2-4 degrees C), and the other half were kept at room temperature (25 degrees C, global ischemia). Immediately and 4, 8, 12, 16, and 24 h after amputation, muscle tissue samples were stained with the Feulgen reaction and analyzed by an image-analysis system to detect DNA contents in muscle cell nuclei. Samples from carotid arteries were examined with a transmission electron microscope. The results showed that the DNA content in muscle cell nuclei was slightly decreased at 4 and 8 h of global ischemia. At 12 h after global ischemia, the DNA content was found to be significantly decreased (80.03% of baseline). The DNA content dropped to 53.93% of baseline at 16 h of global ischemia. However, in the muscle that was preserved at cold temperature, the DNA contents were only slightly changed along with the ischemia time at 24 h. The DNA changes were confirmed by transmission electron microscopic observations. The present findings could provide evidence for the study of revascularization of ischemic muscle.

Amputation, Surgical↗
PubMed2006

Recipient vessels for microsurgical flaps to the groin and pelvis: a review.

Reconstruction of large defects of the pelvis and groin sometimes requires microsurgical flaps when the otherwise rich supply of local options fails to be sufficient in difficult and complicated cases. Recipient vessels for microsurgical flaps to the groin and pelvis are important elements in planning such procedures. Seven groups have reported pelvis and groin microsurgical flap cases, and their recipient vessels have included the superior and inferior gluteal vessels, the femoral vessels, the deep perforators of the femoral system, the inferior epigastric vessels, intra-abdominal vessels, and interpositional vein grafts to distant recipient vessels. This review summarizes their experience and describes the recipient vessel options in the pelvic and groin region.

Arteries↗
PubMed2006

Intramuscular administration of vascular endothelial growth factor augmenting collateral circulation in a rat hindlimb replantation model.

This study evaluated the effect of exogenous vascular endothelial growth factor (VEGF) on augmentation of collateral circulation in a rat hindlimb replantation model. Twenty-eight rats, divided into four groups, underwent right hindlimb replantation. In experimental Group 1, the rats received daily intramuscular VEGF injections (1 microg/kg). In Group 2, the rats received 25 microg/kg VEGF injections. In Group 3, the rats received 50 microg/kg VEGF injections. In Group 4, the control group, rats received saline injections. Seven days after replantation, the repaired femoral vessels were excised. Seven days after excision of the femoral vessels, toe necrosis ratios of the replanted hindlimbs were grossly examined, and calf blood pressures were measured. Angiography was performed and muscle tissue was biopsied for histology. The results showed that administration of VEGF significantly decreased toe necrosis and improved calf blood pressure ratio, angiographic score, and capillary density in the replanted hindlimbs that underwent late vessel excision. The effect of VEGF was significantly dose-dependent. The authors conclude that VEGF can augment angiogenesis and collateral vessel formation in replanted limbs, and improve survival in replanted limbs with potential late arterial insufficiency.

Analysis of Variance↗
PubMed2006

Treatment of infected wounds with maggot therapy after replantation.

Postoperative wound infection is a rare, but major, complication of replantation. Failure to control infection can lead directly to vascular thrombosis and, in turn, to loss of the replanted extremity. The use of maggots for wound debridement has a long history and has been lately re-introduced for treatment of intractable wounds. In this report, the authors present the experience of successful debridement of a severely infected wound after forearm replantation, using maggot therapy. The results and mechanism of maggot therapy are discussed.

Adult↗
PubMed2006

Proinflammatory cytokines gene expression in skin flaps with arterial and venous ischemia in rats.

Infiltration of inflammatory cells is the crucial element in ischemia-reperfusion injury of the microsurgical flap. Cytokines are a large functional group of polypeptide regulatory molecules that influence the activity of various cell types through autocrine and paracrine mechanisms. In this study, expression of selected proinflammatory cytokines was examined in skin flaps with arterial and venous ischemia in the rat model. Fifty-four Sprague-Dawley rats were used in the study. The ischemia of each flap was induced by clamping its vascular pedicle for 6 hr. The flap was then replaced and allowed to reperfuse. All flaps were biopsied immediately post-event, and at 3, 6 and 18 hr after reperfusion. Expression of tumor necrosis factor (TNF-alpha), interleukin (IL-1beta), and monocyte chemoattractant protein-1 (MCP-1) mRNA was determined by RT-PCR in each case. The same number of skin flaps without ischemia was used for baseline gene expression. Results showed that the TNF-alpha expression was significantly up-regulated in the flaps with arterial ischemia at 6 hr after reperfusion. In the flaps with venous ischemia, MCP-1 expression was increased with its peak expression at 3 hr after reperfusion. IL-1beta expression was increased threefold in the flaps subjected to venous ischemia and following reperfusion in 3 hr, but the peak expression in the flap with arterial ischemia was observed at 18 hr after reperfusion. This study delineated the changes in expression of these proinflammatory cytokines in flaps with arterial and venous ischemia reperfusion injury, and showed that cytokine expression was different in the arterial and venous injuries.

Animals↗
PubMed2006

Reconstruction of long cervical esophageal defects with the radial forearm flap.

The radial forearm flap has been used for reconstruction of the cervical esophagus most often as a patch or for circumferential repair of short defects (less than 5 cm). In the following three cases, the radial forearm flap was used to reconstruct circumferential cervical esophageal defects ranging from 5 to 12 mm in length. These procedures were successfully carried out in three patients in whom the intraoperative defect was unexpectedly large or the intra-abdominal viscera harvest would have been difficult. These patients had reliable esophageal function 8 to 24 months after surgery. We conclude that the radial forearm flap can be used for reconstruction of large circumferential defects of the cervical esophagus.

Adult↗
PubMed2006

Improvement of venous flap survival by application of vascular endothelial growth factor in a rat model.

Expression of vascular endothelial growth factor (VEGF) in the venous flap and the effect of exogenous VEGF on survival of the venous flap were studied in rats. A 4- x 4-cm groin type 2 venous skin flap was used in the study. In part 1, biopsies were taken from the flap at 0, 6, 12, 24, and 48 hours after the flaps were raised. VEGF gene expression was measured. In part 2, exogenous VEGF (1 microg/mL) was injected subdermally into the flaps in 10 rats before the flaps were replaced. Flaps that received a saline injection were used as the control. Skin paddle survival was measured on postoperative day 7. The results showed that VEGF expression was significantly increased at 24 and 48 hours after venous flap elevation (P < 0.05). Injection of exogenous VEGF to the flap significantly improved survival of the flap (73% of the flap) when compared with the control, which had a 39% mean percent survival (P < 0.05). We conclude that VEGF expression was increased in the venous flap. Administration of exogenous VEGF significantly improved survival of the venous flap.

Animals↗
PubMed2006

Neuroma-in-continuity model in rabbits.

The present study presents a model for creation of neuroma-in-continuity in the rabbit, confirmed by histologic study, electrophysiology, and examination of molecular markers. Twelve New Zealand rabbits were used. The lateral fascicule of the peroneal nerve with 15-mm in length was resected. In the intervals from 4 to 6 weeks postoperatively, the histology showed the typical pathologic changes of neuroma by hematoxylin-eosin (HE), Luxol fast blue, and Van-Gieson staining. As compared with the healthy nerve, the motor nerve conduction velocity (MCV) and compound motor action potential (CMAP) were found significantly slowed and reduced. The expression of ciliary neurotrophic factor (CNTF) in nerve and calcitonin gene-related peptide (CGRP) mRNA in L7, S1 dorsal root ganglia were downgraded and upgraded, respectively, with formation of neuroma-in-continuity. These electrophysiologic and molecular markers' expression data can be used as reliable parameters for evaluation of management of the neuroma-in-continuity.

Animals↗
PubMed2006

Luminal fillers in nerve conduits for peripheral nerve repair.

The use of nerve conduits as an alternative for nerve grafting has a long experimental and clinical history. Luminal fillers, factors introduced into these nerve conduits, were later developed to enhance the nerve regeneration through conduits. Though many luminal fillers have been reported to improve nerve regeneration, their use has not been subjected to systematic review. This review categorizes the types of fillers used, the conduits associated with fillers, and the reported performance of luminal fillers in conduits to present a preference list for the most effective fillers to use over specific distances of nerve defect.

Biocompatible Materials↗
PubMed2006

Treatment of painful neuroma of amputated phalanx with distal toe transfer: a case report.

A painful neuroma in the amputation stump of a finger can be psychologically and physically disabling. Numerous surgical procedures have been attempted to prevent and treat amputation neuromas of the finger, but the results are inconsistent. Microsurgical transfer of the distal second toe to the amputated stump of the finger can provide a pathway and target for the regenerating axons and avoid recurrence of neuromas. In this article, we present the experience of successful treatment of amputation neuromas of an index finger with microsurgical distal toe transfer.

Amputation, Traumatic↗
PubMed2005

Microsurgical fibular graft for full-length radius reconstruction after giant-cell tumor resection: a case report.

In this article, we present the treatment of a recurrent giant-cell tumor of the radius with en bloc resection and full-length radius reconstruction with a 24-cm long microsurgical fibular graft. At time of 8-year follow-up, there was no evidence of tumor recurrence. A satisfactory range of motion of the elbow, wrist, and forearm was maintained. There was no instability in the joints, and grip strength measured 63% of the opposite side. With appropriate dynamic tendon transfer, this procedure can provide an alternative method for reconstruction of the full-length radius after tumor resection, with functional and durable results.

Adult↗