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Biomedical subjects

B M O'Brien

Publications and source records attributed to B M O'Brien.

At least 127 records · Page 7Linked to original sources
PubMed1984

The late functional results of upper limb revascularization and replantation.

The functional results in 25 of 30 patients after successful upper limb revascularization or replantation were evaluated by subjective-patient surveying and objective measurements. Young patients with complete, sharply amputated extremities at the wrist level or those with incomplete injuries and uninjured peripheral nerves had the best functional results. Multiple-level, diffuse crush, or avulsion injuries, even if the injuries were incomplete, and patients with high-level nerve injury had less return of function.

Adolescent↗
PubMed1984

Ring finger transfer in reconstruction of transmetacarpal amputations.

Four cases are described in which the opposite ring finger was used for finger reconstruction in transmetacarpal hand amputations. Thumb reconstruction was required in three of these four cases. This was achieved by hallux transfer, tube pedicle combined with an innervated first foot web neurovascular free flap, and second toe transfer respectively. In the fourth case, where a thumb was not required, double finger reconstruction was performed by the use of a second toe combined with a ring finger. This case highlights the limitations of the second toe for finger reconstruction, particularly in achieving palmar-digital grip. The advantages of the ring finger are length and mobility, especially sophisticated intrinsic muscle movement, sensory capacity, strength, wider span, and esthetic excellence.

Adolescent↗
PubMed1984

Survival factors in replantation and revascularization of the amputated thumb--10 years experience.

An unabridged series of 73 thumb amputations subjected to replantation or revascularization surgery in the years 1971 to 1980 has been examined in detail as a combined prospective and retrospective study to determine the factors playing a role in survival and failure. The causes of failure and complications are demonstrated. The overall failure rate was 27%. The factors influencing the outcome were: the injury--mechanical type and degree of amputation; the patient--age and amputation level; and the surgeon--frequency of utilization of vein grafts. The highest failure was seen in the complete amputation with avulsion/diffuse crush injury group (63%). Incomplete amputations had the lowest failure rate, particularly if the injury type was guillotine/local crush and at a level proximal to the metacarpophalangeal joint. Patients aged 11 to 20 years had a low failure rate (18%) whereas children under 5 years had a high failure rate (40%). Arterial thrombosis was the most frequent complication and cause of failure. The surgeon could modify the result by frequent use of vein grafts for arterial reconstruction and by reoperation for thrombotic complication. Five thumbs failed to revascularize at the primary operation and were removed at this primary operation.

Adolescent↗
PubMed1983

Effect of nicotine on blood flow and patency of experimental microvascular anastomosis.

Nicotine is known to have deleterious effects on the cardiovascular system, causing vasoconstriction and increased blood pressure. A drop in blood-flow velocity in humans, endothelial damage in rats, and inhibition of platelet aggregation in rabbits' blood have all been shown experimentally. In this article two studies are described that investigate the effects of nicotine on microvascular anastomotic patency. In experiment 1, electromagnetic blood-flow recordings were made in the saphenous artery of the saphenous flap after intraarterial installation of nicotine. Decreased blood flow was consistently recorded up to a maximum of 72% of normal flow. In experiment 2, rabbit femoral arteries were anastomosed and the patency rates at three weeks checked after various combinations of pre- and postoperative intraperitoneal nicotine had been injected. There was no significant increase in thrombosis between the groups treated with nicotine and the control. Although no thrombosis occurred in these experiments, decreased blood flow was noted in the saphenous flap in the dog. This slowing of flow should predispose to thrombosis, especially if other factors associated with the vascular repair were suboptimal. It is concluded in view of this study and the observed clinical effects in 2 patients with microvascular transfer that smoking in the perioperative period should be avoided.

Animals↗
PubMed1983

Scanning electron microscope study of microvenous grafts to artery.

The healing of microvenous grafts to femoral arteries in the rabbit has been studied using scanning electron microscopy at intervals ranging from zero time to 5 months. Healing of the grafts followed a similar pattern to that of end-to-end repairs. Postoperative survival of the original endothelium was far superior in the vein than in the artery. Re-endothelialization was completed by 2 weeks. No dilation of the graft or aneurysm formation appeared. A detailed account of the healing vein grafts has been reported and will enable comparison of healing of microvascular heterografts.

Animals↗
PubMed1983

Comparison of vascular hemodynamics in experimental models of microvascular anastomoses.

Blood flow was measured in the canine saphenous artery using electromagnetic flowmetry. Significant increase in blood flow was noted after occlusion of the distal femoral artery. However, after raising a saphenous island flap there was no significant change in the blood flow before and after distal femoral artery occlusion. The flap peripheral resistance and blood flow were compared after end-to-end and end-to-side anastomosis and no statistical difference was noted.

Animals↗
PubMed1983

The instep of the foot as a fasciocutaneous island and as a free flap for heel defects.

The instep flap needs neither muscle nor a transposition base for survival or innervation. It can be transposed as an island fasciocutaneous flap either on the medial or lateral plantar neurovascular bundles or both, and it can be transferred also as a free flap from the opposite foot. Four cases demonstrating the use of the flap as an island and free flap are presented with follow-up ranging from 1 to 2 years. The absence of muscle in the flap provides greater stability of the heel reconstruction and results in a lesser secondary defect. Sensation in the flaps is diminished but adequate for long-term function, but hyperkeratotic reaction remains an unpredictable problem. The ability to transfer the flap as a free transfer widens the scope of the flap to reconstruct both heel and forefoot defects where local instep tissue or vascularity are inadequate for local reconstruction. The secondary defect, particularly when no muscle is included in the flap, has been minimal.

Adolescent↗
PubMed1983

Microsurgical repair of the fallopian tubes.

The microsurgical techniques used and the results achieved in a series of 27 patients submitted for fallopian tube repair are presented, the majority following elective sterilization.

Adult↗
PubMed1982

The computer programmed multi-image lecture.

Computer programmed multi-image presentations enhance considerably the visual content of an audiovisual presentation. A multi-image production provides ample opportunity to present the pre- and post-operative images simultaneously, enabling the audience to compare and comprehend the results with ease. With more than one image the natural sequence of dissection details can be shown, resulting in continuity of thought. The dissolve mechanism offsets any visual fatigue of the audience. The films contribute animation sequences which cannot be demonstrated well on slides. A presentation of all material provides the lecturer with maximum control with the minimum of effort, utilising one button. A computer programmed multi-image production is a complex medium of audiovisual presentation and needs a great deal of time and experience and is not to be lightly undertaken. With the increased number of slides, images and projectors the margin for error is small. Careful slide assembly and repeated rehearsals are the keys to success. At the moment, its use is recommended for special lectures only with adequate consideration being given for the increased expense of production.

Audiovisual Aids↗
PubMed1982

Free microneurovascular muscle transfer in limbs to provide motor power.

The experience gained in a series of 7 free microneurovascular muscle transfers to the limbs over a seven-year period has led us to conclude that: free gracilis microneurovascular flaps can be safely transferred and can aid restoration of movement following severe injuries of the limbs, including post-replantation cases; inclusion of a cutaneous island with the muscle is safe, improves cover, and simplifies closure following muscle transfer; tendon adhesions and joint stiffness are the greatest obstacles to transferred muscle function, and early passive extension is recommended; additional procedures are usually required after muscle transfer, to improve the level of function; and additional experimental work is required to determine methods of establishing the correct resting tension in transferred muscles.

Adolescent↗
PubMed1982

Digital reconstruction in the mutilated hand.

Salvage and reconstruction of the mutilated degloved hand or digit pose a problem because of the deficiency of local innervated pulp tissue. Free neurovascular flaps from the first web space of the foot supply a large area of well-padded innervated glabrous skin to resurface such defects. In thumb reconstruction free flaps, which may include the toenail, have many advantages over the conventional ring-finger island flap. Finger and whole-toe transfers are innervated reconstruction par excellence and these, in combination with innervated free flaps, offer a large armamentarium for reconstruction. The quality of sensation, however, is poorer than normal in these transfers and they are therefore limited to circumstances in which their use is not substituted by adjacent normal units.

Finger Injuries↗