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Biomedical subjects

W A Morrison

Publications and source records attributed to W A Morrison.

At least 19 recordsLinked to original sources
PubMed1992

Biochemical analysis of the venous flap in the dog.

There has been great interest stimulated by reports on factors influencing the survival of skin flaps which possess only venous inflow and outflow, i.e., venous flaps. The present study serially (Days 1, 2, and 4 postoperatively) observed several biochemical factors which might affect flap survival. ATP levels were measured to assess endogenous energy stores, malonyldialdehyde (MDA) and xanthine oxidase (XO) to estimate free radical production, superoxide dismutase (SOD) to quantify antioxidant defenses, and edema to measure inflammatory changes. Eighteen thighs on nine dogs were assigned randomly to one of three groups: full-thickness skin grafts, flaps based solely on the saphenous artery and vein (AV flaps), or flaps based solely on the saphenous vein (venous flaps). These were regarded as being mostly ischemic, totally perfused, and partially ischemic, respectively. Control skin biopsies were obtained adjacent to surgical sites. AV flaps and control skin were similar in all respects. Venous flaps compared with skin grafts were significantly less edematous (P less than 0.01) had less MDA and XO (P less than 0.05), but no significant differences in SOD and ATP levels. However venous flaps had significantly less ATP than AV flaps (P less than 0.01). Thus venous flaps survive despite depletion of ATP levels. These results suggest that decreased free radical production and lessened edema may be important factors in promoting ultimate survival of venous flaps.

Adenosine Triphosphate↗
PubMed1992

The plantaris tendon as a tendo-osseous graft. Part I. An anatomical study.

Comparative studies have shown that bone-bone union develops faster than a junction between grafted tendon and bone, and would thus allow earlier post-operative movement, limiting adhesion formation. In this context the nature of the insertion of the plantaris tendon into the calcaneus is reviewed as a possible source of composite bone-tendon grafts. It is proposed that the composite plantaris tendon with its bony block attachment is inserted through a hole in the distal phalanx of the finger creating an immediate firm distal fixation. From cadaver dissections it was found that in at least 80% of cases the insertion of the plantaris tendon was directly into the calcaneus, independent of the tendo Achilles, and was therefore suitable for use as the proposed tendon graft.

Bone Transplantation↗
PubMed1992

The plantaris tendon as a tendo-osseous graft. Part II. Clinical studies.

To minimize adhesions following tendon repair, early post-operative movement is recommended. This has proved difficult with tendon grafting because of weakness of the repair sites, particularly distally, and because of slow revascularization. A potential solution is the use of a composite tendon-bone graft in which a bone block is attached to the end of the tendon. The tendon is threaded through a hole in the distal phalanx from the dorsal to the palmar side and impacted like a cork to create an immediate strong fixation. The tendon itself is then tunnelled through the pulley system and the proximal repair is carried out with a multiple weave technique which can withstand immediate active movement. The ideal tendon-bone complex is the plantaris attached to a segment of calcaneus. A preliminary report with two case studies is presented.

Adult↗
PubMed1992

Review of Swanson trapezium implants.

Sixteen Swanson trapezium silicone prostheses are reviewed retrospectively an average of 3 years after insertion. Fifteen were performed for osteo-arthritis and one for rheumatoid arthritis. Despite a very high patient satisfaction, 14 thumbs had residual functional compromise and caused pain when performing certain tasks. Three implants were completely dislocated and another four were significantly subluxed. One patient required implant removal. Intra-osseous cysts or significant bony erosion around the implant were present in five thumbs. It is concluded that there are early significant problems associated with this procedure which make it unsuitable for use in the osteo-arthritic thumb.

Aged↗
PubMed1992

Thumb and fingertip reconstruction by composite microvascular tissue from the toes.

Toe-pulp web flaps have the potential to almost replicate the missing tissues resulting from defects of the thumb and fingers. The possibility of short- and long-term donor site morbidity and the technical demands of these transfers limit their use mainly to largish defects on the dominant sensory aspects of the radial digits. This limitation is especially true of the thumb, where a large volume of tissue is usually required. The toenail can be included or transferred alone. A logical extension of these pulp and nail flaps is the wrap-around procedure for total thumb amputations at or distal to the metacarpophalangeal joint. In this procedure, a sleeve of skin, pulp, and nail is wrapped around an iliac crest bone graft to create an almost exact size match of the missing thumb while preserving all of the toes. Palmar or first-web defects in the hand do not need specialized skin replacement for function, and foot flaps are rarely indicated in these sites.

Finger Injuries↗
PubMed1992

Recent advances in plastic surgery.

Scarless healing and the creation of like-tissue for reconstruction have been the aims of plastic surgery since its inception. Recent advances bring us even closer to the ideal.

Cicatrix↗
PubMed1990

Prefabrication of thin transferable axial-pattern skin flaps: an experimental study in rabbits.

The arteriovenous pedicle of all known axial-pattern skin flaps enters from the deep aspect and consequently the flap must contain fat and/or muscle and be of considerable thickness. In an attempt to fabricate a thinner axial-pattern flap the femoral artery and vein of rabbits were implanted, in various vascular configurations, directly into the subdermal layer of the skin. Implantation was found to provoke an extensive outgrowth of new vessels from the implanted artery and vein, and the progress and pattern of this neovascularisation was studied by carbon gelatine perfusion and histology. Neovascularisation begins within a few days of implantation and progresses rapidly. By 8 to 12 weeks it is possible to elevate regularly a viable, large skin flap based on the implanted pedicle.

Animals↗
PubMed1990

Microvascular nail transfer.

A composite of nail and its skin appendages can be transferred for the foot to the hand by microvascular anastomosis. For technical reasons, the most suitable donor nail is from the big toe, and this most closely approximates the thumb nail. A finite portion of hemipulp must be included with the transfer to ensure adequate vascularization. Nail size can be reduced by resection of the edges of the germinal matrix so as to match the donor defects. For finger nail reconstruction, it is usually more practical to transfer the whole of the tip of the second or third toe to replace the whole of the tip of the finger. The indications of nail reconstruction by this technique are relatively rare and are predominantly cosmetic.

Age Factors↗
PubMed1990

Results of management of facial palsy with microvascular free-muscle transfer.

This paper reports our experience in facial reanimation using free innervated muscle transfer in 69 patients with long-term facial palsy. The majority of patients were treated in two stages with cross-facial nerve graft as the first stage and microvascular muscle transfer at the second stage. The gracilis muscle was used in 62 patients. A system of grading results has been utilized in the long-term evaluation. The overall final result was excellent or good in 51 percent of 47 patients who were available for follow-up. Although the results are not completely satisfactory, they justify the use of this approach to a difficult clinical problem. The results are improving as technical modifications to the procedure have evolved. The gracilis muscle is a reliable free transfer with internal anatomy conductive to use for reanimation of the paralyzed face. This type of transfer, in our experience, has proved superior to nonmicrosurgical methods for treatment of complete and severe incomplete facial palsy. The seventh cranial nerve is used in the innervation of the transferred muscle, the ipsilateral being preferable if available. The authors believe that use of the same cranial nerve is superior to methods that involve other cranial nerves, where spontaneity is often not achieved.

Adult↗
PubMed1978

Microvascular great toe transfer for congenital absence of the thumb.

Two cases of microvascular great toe transfer for congenital absence of the thumb in children are reported. A rationale and operative details are discussed. A long term follow up is needed, but at this stage the results are most encouraging. There has been no interference with gait.

Child, Preschool↗
PubMed1978

Neurovascular free flaps from the foot for innervation of the hand.

Microneurovascular flaps from the first web space of the foot offer a solution to upgrade sensibility of the denervated hand. Based on the dorsalis pedis artery, it allows simple dissection and a large vessel for easy and safe anastomosis. Seven cases are presented in which combinations of the first web anatomy for a variety of denervation injuries were used. The technique is ideally suited in those cases where no areas of island flap tissue are available for transfer.

Adolescent↗
PubMed1978

Neurovascular free foot flaps in reconstruction of the mutilated hand.

The neurovascular free flap from the first web region of the foot affords unrivalled potential for refurbishing sensibility to the denervated hand. Its greatest application is when no conventional island flap tissue remains for transfer. Its two-point discrimination is only moderate, but when used for thumb reconstruction, its sensibility is adequate because no functional substitute exists. Functionally and cosmetically it is superior to other methods of thumb reconstruction because of its pulp, size, and nail availability. There are no finger identification problems and secondary donor defects are minimal.

Adult↗