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Biomedical subjects

W A Morrison

Publications and source records attributed to W A Morrison.

At least 73 records · Page 4Linked to original sources
PubMed1996

A morphological study of the long-term repair process in experimentally stretched but unruptured arteries and veins.

As many avulsion amputations are incomplete and the vessels remain intact, the immediate pathology and long-term repair process (to 3 months post-injury) of experimentally stretched but unruptured rabbit femoral arteries and veins were examined. In stretched arteries, circumferential skip lesions involving endothelium, internal elastic lamina (IEL) and media occurred frequently and often up to 3 cm from the point of stretch. Medial smooth muscle cells (SMC) were significantly damaged or lost at lesions. Macrophages and neutrophils were found in lesions 1-4 days post-injury. Between 2-4 days, lesions were covered by endothelium and synthetic state SMC appeared in the media. At 1 week, a thin neointima (which persisted to 3 months) covered many lesions. The media at lesions gradually filled with SMC but generally remained disorganised even at 3 months post-injury. Stretching caused tears in vein walls, particularly close to the point of injury. There was no evidence of venous damage or repair in specimens examined 3 weeks and 3 months post-injury.

Amputation, Traumatic↗
PubMed1996

A modified surgical technique for temporalis transfer.

A modification of the temporalis muscle transfer for facial animation in facial palsy is described. Seven cases are presented which demonstrate the advantages of the procedure, especially the avoidance of temporal hollowing and the greater power due to less dissection of the muscle belly, a more direct line of pull and the absence of a pulley. In addition, food pooling in the buccal sulcus is reduced, and the procedure is less extensive and thus better tolerated.

Adult↗
PubMed1996

Spontaneous thrombosis of palmar digital veins.

Five cases of spontaneous thrombosis of a palmar digital vein are presented. The patients, all female, complained of a tender and unsightly lump over the digital palmar surface at the proximal interphalangeal joint level. Two fingers were affected in one patient. None could recall any history of trauma. In four cases a surgical excision was carried out. Histology confirmed the intraoperative findings of thrombosis of a superficial digital vein in every case. All patients are free from recurrence at a mean follow-up of 2.5 years.

Adult↗
PubMed1996

Dupuytren's disease occurring after a surgical injury to the hand.

We report three clinical cases in which Dupuytren's disease was triggered by surgical trauma. All patients developed the contracture between 3 weeks and 3 months after operation for unrelated pathology of the hand. They had significant swelling of the hand postoperatively, preventing full mobilization. They did not have a strong diathesis for the disease. Since the appearance of the contracture, they have not developed the disease in the contralateral hand or anywhere else in the body. In one case, a similar operation on the contralateral band has not provoked onset of the disease.

Carpal Tunnel Syndrome↗
PubMed1996

Reverse radial artery fascial flap: a treatment for the chronically scarred median nerve in recurrent carpal tunnel syndrome.

Six patients underwent re-exploration of the carpal tunnel for symptoms of recurrent median nerve compression. All patients had previously undergone two or more decompressions. Operative findings revealed evidence of chronic scarring of the median nerve with flattening and perineural fibrosis. Following decompression together with neurolysis and tenosynovectomy, a vascularized fascial flap pedicled distally on the radial artery was used to envelop the median nerve. Follow-up studies of between 12 and 61 months (mean, 25 months) showed improvement of symptoms in all patients, with 2 patients describing complete relief of pain and paresthesia and 4 patients describing mild intermittent pain or paresthesia.

Carpal Tunnel Syndrome↗
PubMed1996

Urethral reconstruction using the radial artery forearm free flap: conventional and prefabricated.

For successful reconstruction of the scarred urethra it is logical to employ well-vascularized skin flaps. The radial artery forearm free flap is ideal for this purpose. This paper describes the first seven consecutive patients in whom we have used this flap for urethral reconstruction. In one, the forearm skin was too hirsute for urethral lining, and a prefabricated hairless skin flap was created by application of a preliminary full-thickness skin graft from a nonhairy site onto the forearm fascia. The longest follow-up is 5 1/2 years.

Adolescent↗
PubMed1996

Synovial sarcoma: an unexpected ultrasound finding in a post-partum patient.

A 20-year-old patient presented after an uneventful pregnancy and delivery with an asymptomatic soft-tissue mass behind her knee with the clinical features of a ganglion or Baker's cyst. An ultrasound scan demonstrated a well-defined but solid mass with prominent vascularity. The mass was noted to increase in size prior to surgery. The pathological diagnosis was that of a synovial sarcoma grade 2, a rare malignant mesenchymal neoplasm with a serious prognosis.

Adult↗
PubMed1996

Temporal and spatial relationship between no-reflow phenomenon and postischemic necrosis in skeletal muscle.

The aim of these experiments was to describe clearly the spatial relationship between the no-reflow phenomenon and tissue injury in postischemic skeletal muscle. Using the rectus femoris muscle of anesthetized rabbits, we examined microvascular perfusion in untreated muscles and in muscles after 3.5 h of ischemia and 10 min, 1 h, and 24 h of reperfusion. Microvascular perfusion was assessed by infusion of biological ink and quantitation of 1) the area of capillary filling in histological sections, and 2) the ratio of perfused capillaries to muscle fibers in perfused areas (C/F). After 10 min of reperfusion, perfused cross-sectional area had decreased from 67.0 +/- 20.0 to 10.6 +/- 5.6 (SD)%, and C/F was also significantly reduced. These changes persisted for at least 24 h. After 10 min of reperfusion, flow was randomly distributed throughout the muscle. However, after 24 h, perfusion was confined to the peripheral tissue in areas that were also viable as demonstrated by nitro blue tetrazolium staining. These results show that in this model, in the early stages of reperfusion, flow is established in some areas, which are destined to become necrotic.

Animals↗
PubMed1996

Free tensor fasciae latae flap reconstruction of defects of the chest and abdominal wall: selection of recipient vessels.

Reconstruction of a full thickness defect of the abdominal or chest wall requires a combination of a rigid or semi-rigid layer and skin cover. The tensor fasciae latae (TFL) flap is unique in that it provides both of these in substantial quantities, but the most difficult aspect of using this flap in the anterior chest and abdomen is finding suitable recipient vessels. We describe a series of nine cases in which full thickness defects of the chest and abdominal wall were repaired using free vascularised TFL flaps. The recipient vessels included the gastroepiploic vessels (n = 2), the deep inferior epigastric artery (n = 3), the internal mammary artery (n = 2), and the superior thyroid and acromiothoracic arteries (n = 1 each). The gastroepiploic and internal mammary vessels are preferred because of their reliability and because the flap pedicle enters the centre of the deep surface of the flap so that if these vessels are used, circumferential tight closure of the fascial layer can be achieved, with consequent decreased risk of vessel kinking and future herniation.

Abdominal Muscles↗
PubMed1995

Island inner canthal and glabellar flaps for nasal tip reconstruction.

A series of inner canthal and glabellar island flaps for nasal tip reconstruction based on the angular artery and vein is presented. These flaps have the advantages of providing well vascularised tissue of the appropriate colour, texture and thickness for external skin and vestibular lining, with a wide arc of rotation and satisfactory donor site defect, in a single stage procedure.

Aged↗
PubMed1995

Cool perfusion solutions for skin flaps: a new mixture of pharmacological agents which improves skin flap viability.

This study tested the hypotheses that perfusion of cooled skin flaps with established organ preservation solutions improves their viability and that this improvement can be further enhanced by pharmacological manipulation. Rabbit epigastric skin flaps were perfused with different solutions before explantation and stored at 8 degrees C for 6 days. In the first part of the experiment, flap viability was assessed 7 days after reperfusion of the flap via microvascular anastomoses. The different solutions were heparinised blood, University of Wisconsin solution, two of its modifications, EuroCollins solution and a pharmacological mixture containing phosphoenolpyruvate, desferrioxamine, nitrendipine, dextran 70 and a platelet-aggregating factor receptor antagonist (WEB 2170). In the second part, biochemical parameters of skin were measured at various reperfusion times. Adenosine triphosphate (ATP), reduced glutathione (GSH), myeloperoxidase (MPO) and tissue water were assayed at 0, 1, and 24 h after reperfusion. In addition, plasma thromboxane (TXB2) was measured at 0, 30 and 60 minutes after reperfusion. The viability of flaps perfused with the mixture (81%) was significantly higher than that of any of the other groups (39% for controls, 38% for EuroCollins, 13% for UW solution, 27% and 31% for its modifications). ATP levels after reperfusion were higher in the mixture group than in UW-perfused group. GSH levels in the mixture group were also higher than in the UW group, indicating higher level of protection against oxidative stress during reperfusion. There were no differences in MPO levels. Thromboxane levels associated with UW-perfused flaps were significantly higher than those associated with any other perfusion solution. In conclusion, perfusion of a mixture of pharmacological agents targeting specific aspects of ischaemia/reperfusion injury improved the viability of skin flaps stored in the cold for 6 days, whereas standard organ preservation solutions failed to affect significantly skin flap survival.

Adenosine↗
PubMed1995

The effect of cold ischemia on the patency of microvascular repair following arterial avulsion injury.

UNLABELLED: Avulsion injuries have a poor prognosis for survival in clinical replantation surgery. Arterial thrombosis is the most significant factor contributing to avulsion replant failure, and severe arterial damage has been observed with this injury. However, patency rates of experimentally avulsed arteries repaired immediately are much higher than in the clinical situation. This paper evaluates the effect of an added component--ischemia--on the patency of experimentally avulsed arteries. All avulsions seen clinically are subject to some degree of ischemia prior to replantation. Ninety rabbits had both femoral arteries avulsed under general anesthesia. A 6.5-cm graft was harvested from the left distal femoral artery. In 20 rabbits (group 1: 0 hours of ischemia) the graft was immediately inserted into the defect in the right femoral artery. Sixty rabbits (20 grafts per group) had their grafts stored at 4 degrees C for either 10 hours (group 2), 18 hours (group 3), or 24 hours (group 4) and reinserted into the right femoral artery in a second operation. Patency was assessed 3 weeks after reinsertion. Groups 1 and 2 maintained high patency rates (85 percent); however, group 3 (70 percent) and group 4 (45 percent) had lower patency rates than group 1, with a significant difference between groups 1 and 4 (p < 0.01). In a fifth group (10 grafts), avulsed 24-hour ischemic grafts were hydrodilated prior to reinsertion. The patency rate of this group increased significantly (90 percent) compared with group 4 (p < 0.005). CONCLUSION: These experiments suggest that a combination of avulsion injury and ischemia time is responsible for the poor clinical results of avulsion replantations.

Animals↗
PubMed1995

The role of cellular adhesion molecules in surgery.

The purpose of this review is to detail the roles played by the cellular adhesion molecules (CAM) in inflammatory and immunological reactions relevant to surgery. The interactions between leucocytes and endothelial cells which are mediated by CAM are central to the development of ischaemia/reperfusion injury (IRI) as occurs when blood flow is restored after an ischaemic period; for example, following revascularization of replanted digits and microvascular tissue transfers, angioplasty and tourniquet procedures. Cellular adhesion molecules are also important in wound healing and other inflammatory processes. In addition, the immunological response to organ allograft transplantation is mediated by cellular interactions mediated by CAM. This review details the functions and regulation of the various CAM involved in inflammation and allograft rejection and summarizes the results of previous surgical studies in which various techniques have been used to block the interactions mediated by CAM in an attempt to improve surgical outcomes.

Cell Adhesion Molecules↗
PubMed1995

Vascularised flexor tendon grafts.

In densely scarred digits, tendon reconstruction fails because of paucity of blood supply. This inevitably leads to adhesion formation and failure of gliding. Staged tendon grafting with silicone spaces can improve results but does not ameliorate the essential problem of reduced vascularity and may indeed worsen it. Tendon grafts can be implanted with their own living sheaths as free or pedicled vascularised transfers from the foot or forearm to either extensor or flexor sites in the hand. These mesenteric tendons with their fascial or synovial sheaths intact and vascularised by adjacent vascular pedicles include the extensor hallucis brevis and longus or the extensor digitorum communis on the dorsalis pedis system, the palmaris longus on the radial arterial system, the sublimus tendons of the ring and little fingers on the ulnar arterial system as well as the extensor indicis on the second metacarpal arterial system. These tendon grafts can be inserted into the intact or reconstructed tunnel systems of the digit and repaired proximally and distally to the tendon remnants. Gliding is enhanced although limitations still potentially occur at the proximal tendon junctions.

Amputation, Traumatic↗
PubMed1995

Platelet-activating factor (PAF) receptor antagonism by WEB 2170 improves the survival of ischaemic skeletal muscle.

The platelet-activating factor (PAF) receptor antagonist, WEB 2170, significantly improved the survival of ischaemic rabbit skeletal muscle from 42% in saline-infused muscle to 65% in WEB 2170-infused muscle at 24 hours post reperfusion. Evidence is presented which suggests that WEB 2170 inhibits neutrophil infiltration during reperfusion. In addition, tissue lipid peroxide levels and the release into blood of the enzyme creatine kinase were inhibited by local infusion of WEB 2170. In contrast, the level of oedema in muscles receiving an infusion of WEB 2170 was not different from that in saline controls. It is concluded that infusion of a PAF antagonist into ischaemic skeletal muscle at the time of reperfusion inhibits neutrophil recruitment and activation. These results provide an impetus for PAF receptor antagonism as a means of reducing reperfusion injury in limb replantation surgery.

Animals↗
PubMed1994

An improved matrix-type controlled release system for basic fibroblast growth factor.

Basic fibroblast growth factor is an angiogenic polypeptide with potential application in wound healing and surgery. However, its use in these situations has been hampered by its instability in vivo. Controlled release systems have been developed to overcome this, but as yet high yields of basic fibroblast growth factor from a permanent matrix-type device have been elusive. In the present study we describe a device, based on ethylene vinyl acetate copolymer, capable of releasing active basic fibroblast growth factor for at least three weeks. The yield and duration of release of active growth factor from this device is significantly higher than previously reported for devices of this type. This improved yield is made possible by a variation in the production method used for matrix-type devices.

Delayed-Action Preparations↗