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Biomedical subjects

J W May

Publications and source records attributed to J W May.

At least 55 records · Page 3Linked to original sources
PubMed1992

A socioeconomic analysis of digital replantations resulting from home use of power tools.

Forty-seven digits in 21 patients who sustained partial or complete amputations from the home use of power tools were replanted or revascularized during a 1-year period. This represented 69% of the microvascular surgery performed for hand injuries during that year. The cost of repairing an average of 2.4 digits was $7000 (surgeon's fee) plus $697 per hour (operating room fee), as per fiscal year 1987. Postoperative hospitalization averaged 15 days at a cost of $15,679. Hand rehabilitation averaged 8 months at a cost of $3348. Fifty-four percent of the patients had no insurance. Fourteen of 21 patients (67%) required at least one additional procedure. Two patients had to make a career change after the injury. The majority of patients with digital replantations were dissatisfied with the emotional costs and the number of subsequent operations. Lack of patient and family awareness of the length of the rehabilitative period was particularly evident.

Accidents, Home↗
PubMed1992

An absorbable catheter system for use in microvascular and peripheral vascular surgery: an experimental study in the canine.

An absorbable catheter for use in regional anticoagulation in microvascular and peripheral vascular surgery was studied in 20 sites in 10 adult beagle dogs to answer three questions: (1) Could the polyglycolic acid and trimethylene carbonate catheter withstand intraarterial pressures of infusion and completely absorb over a predictable time interval? (2) Could the catheter be filled with heparin and maintain patency for reuse after a 24-hour interval? (3) Could the catheter be placed in a side branch of a major artery and, after catheter dissolution, maintain long-term patency of the primary feeding artery? The catheters were completely absorbed from 24 to 34 weeks following implantation. The catheters were able to withstand intraarterial pressures, and no evidence of significant thrombosis of the primary feeding artery was seen in any animal studied. No complications of catheter leak, hematoma formation within the catheter placement sites, or sepsis were noted in any of the 20 catheter sites studied.

Absorption↗
PubMed1992

Neurosensory free flaps to the hand. Indications and donor selection.

When used in properly selected cases, a neurosensory free flap provides sensibility, vascularity, and soft-tissue coverage to an injured hand. Appropriate selection of donor flaps based on the need for fine discriminatory or protective sensation is important for optimal results. Because of its thin, glabrous skin and a constant vascular and neural anatomy, the first web-space flap of the foot or its variants provide the best reconstructive choice for restoration of critical sensibility to digital tips or anesthetic amputation stumps. Protective sensibility can be restored with other neurosensory free flaps, but more clinical experience is needed to fully evaluate the reconstructive potential of many described flaps. A distinction must be made between the anatomic description of a free flap with neurosensory potential and the report of long-term sensory ability after clinical transfer.

Foot↗
PubMed1992

Intraoperative physiologic blood flow studies in the TRAM flap.

An intraoperative study was done to establish the functional and quantitative properties of the blood supply to the TRAM flap through the assessment and manipulation of blood flow through the deep epigastric arterial system. Seventeen patients undergoing unilateral postmastectomy breast reconstruction with lower transverse rectus abdominis myocutaneous (TRAM) flaps were studied. The study is divided into two parts: (1) ultrasonic measurement of blood flow in the deep inferior epigastric artery (DIEA), and (2) direct measurement of blood pressure in the deep epigastric arterial system, after division of the deep inferior epigastric artery. With occlusion of the superior epigastric artery at the level of the upper edge of the skin flap, 71 percent of the patients had a decrease in the blood flow through the deep inferior epigastric artery, with an average decrease of 23 percent. This implies that the area of watershed perfusion in the lower TRAM flap is superior to the umbilicus, and therefore, survival of all lower TRAM flap tissues requires reversal in the normal direction of arterial flow to the flap. The blood pressure in the proximal stump of the deep inferior epigastric arterial system averaged 46 percent of the mean systemic blood pressure. Occlusion of the medial and lateral thirds of the isolated rectus muscle decreased the mean arterial blood pressure in the flap an average of 19 percent in 80 percent of the individuals studied. These data support the technique of harvesting the entire rectus muscle, avoiding muscle-splitting maneuvers that may compromise axial blood flow.

Adult↗
PubMed1992

The biophysical and histologic properties of capsules formed by smooth and textured silicone implants in the rabbit.

Capsular contracture remains the major complication of reconstructive and aesthetic breast surgery. The purpose of this investigation was to determine if a silicone implant with a textured surface will form a capsule of significantly different biophysical and histologic properties than conventional smooth silicone. Thirty smooth and 30 textured silicone tissue expanders were implanted under the panniculus carnosus of rabbits. After 3 months, measurements related to contracture were performed on anesthetized animals in an investigator-blinded, controlled manner. Intraexpander pressures were measured as saline was injected over time. We found a significant correlation between intraexpander pressures, applanation tonometry, and Baker class. Histology revealed a thicker, more adherent, and inflammatory capsule around the textured silicone implants as compared with the smooth silicone implants. Dynamic pressures were plotted against volume of saline within the two types of implants. Statistical analysis revealed that the textured implants form a tighter and thicker capsule than the smooth implants after 3 months of observation (p less than 0.005).

Animals↗
PubMed1991

Microvascular reconstruction of major arteries in neonates and small children.

Arterial injuries in neonates and children under 2 years of age, although relatively uncommon, should be treated by prompt exploration and reconstruction using microvascular techniques. In the past, a reluctant attitude has prevailed in cases involving neonates or infants because of small vessel caliber and the problem of spasm. We reviewed our experience with 9 nonreplantation, arterial reconstructions in children under 2 years of age. The most frequent age at reconstruction was 1.0 month and extended from the immediate newborn period to 24 months of age. All patients were at risk for tissue necrosis. Eight children sustained iatrogenic injuries related either to invasive catheter manipulation (n = 6) or operative transection (n = 2). The ninth patient required reconstruction of the subclavian artery sacrificed during excision of a malignant tumor. There were 5 femoral, 1 subclavian, 1 brachial, 1 posterior tibial, and 1 radial artery repairs. Direct arterial repair was accomplished in one patient with a brachial artery thrombus and another with a transected superficial femoral artery. Reversed saphenous vein grafts were used in the remaining patients. Iatrogenic dissection of the ipsilateral iliac artery necessitated use of a femofemoral bypass graft to achieve adequate inflow in one newborn. There were no operative deaths, no reexplorations, and normal perfusion was restored to all involved extremities. We conclude that microvascular technique allows early, successful arterial reconstruction and limb salvage in neonates and small children.

Arteries↗
PubMed1991

An experimental model for the study of canine flexor tendon adhesions.

An experimental model for the study of canine flexor tendon adhesions was designed using a standardized crush-abrasion injury, meticulous sheath closure, and three-week limb immobilization. Ten animals in the experimental protocol were evaluated for visible adhesion formation. With use of a flexor tendon adhesion rating scale, consistent adhesion formation was documented with an average score of 10.4 +/- 2.1 (range, 0 to 12). Five additional animals had biomechanical testing. Applying an increasing load to the proximally divided profundus tendon (0 to 10 Newtons), it was found that the angle of distal interphalangeal joint motion and the displacement of the toe were significantly decreased, and the work generated significantly increased in the experimental versus control digits (p less than 0.05). The consistent production of visible adhesions thus correlates with biomechanical impairments in toe motion and work. The study of agents aimed at diminishing flexor tendon adhesions will thus be facilitated by this reliable model. Systemic or intrasheath administration of agents will be possible.

Animals↗
PubMed1991

Treatment of chronic traumatic bone wounds. Microvascular free tissue transfer: a 13-year experience in 96 patients.

During a 13-year period at the Massachusetts General Hospital, Boston, Massachusetts, 97 microvascular free tissue transfers have been performed for soft-tissue reconstruction in 96 patients following bone debridement for chronic traumatic bone wounds. These 96 patients comprise a continuation study of 18 original patients reported in 1982. During a 13-year follow-up period (mean, 77.1 months), 95.8% of these 96 patients have enjoyed complete wound closure with a lack of drainage after the debridement and free tissue transfer. Most of the patients (89.6%) encountered in this study are ambulatory without assist and 5.2% of patients have undergone amputation. Twenty-three per cent of patients required subsequent segmental bone defect reconstruction in the lower extremity after infection eradication. The pathophysiology of chronic traumatic bony wounds is different from that of chronic hematogenous osteomyelitis and thus a high incidence of long-term successful management can be seen through complete wound debridement and adequate soft-tissue coverage.

Adolescent↗
PubMed1991

Efficacy of intraarterial heparin in maintaining microvascular patency: an experimental model.

Human-grade sodium heparin was studied to determine thrombosis model patency rates between an intraarterial infusion versus an intravenous method of delivery in a rabbit model. Specific differences in patency and partial thromboplastin times were studied in each group and compared with a saline-perfused group. Three animal groups (New Zealand white rabbits) were established (total = 35 animals). Standardized femoral arterial 5-mm inversion grafts (AIG) were done in each animal in each group. The animals in the control group received intravenous saline infusion, while the two treatment groups received intravenous heparin (12 animals) or intraarterial heparin (12 animals minus 1 anesthesia death). The route of instillation of the infusate was selected at random after completing the inversion grafts. A proximal epigastric branch was utilized for access in those animals randomized to the intraarterial group. Intravenous delivery was accomplished by means of a femoral venous catheter in the vena cava. A 72-hour period of infusion was used in all animals. A dose of 45 units per hour of heparin following a 500-unit bolus was used in the intravenous group. After an identical bolus dose, 25 units per hour of heparin was administered in the intraarterial group. The control (saline group) was given 1 cc saline (in a volume equal to the heparin-dosed groups) daily for 3 days. Arterial inversion graft patency rates were assessed by direct inspection at day 5. Systemic and regional (i.e., distal to the inversion graft) partial thromboplastin times (PTT) were measured in representative control, IV, and intraarterial heparin-treated groups. Complications were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1990

Polyphosphate production by strains of Acinetobacter.

Of four strains of Acinetobacter isolated from a pilot plant exhibiting enhanced biological phosphate removal from sewage, two strains (RA3116 and RA3117) accumulated more than 10 times the amount of polyphosphate accumulated by the other two strains (RA3114 and RA3123). Variants isolated from RA3116 and RA3117 showed polyphosphate levels similar to RA3114 and RA3123. No correlation was found between the polyphosphate content of the strains and levels of several enzymes that have been implicated in polyphosphate formation.

Acinetobacter↗
PubMed1990

Surgical management of ulnar artery aneurysms.

In a ten-year review (1978 to 1988), ten ulnar artery aneurysms in nine male patients were studied. Blunt trauma led to 70%, penetrating trauma to 20%, and 10% had no history of trauma. Three cases were seen as asymptomatic palmar masses with brief antecedent histories of 4 weeks or less. Seven patients with aneurysms had persistent vascular hand symptoms for 6 weeks or longer. All seven symptomatic lesions proved to be sources of emboli. Diagnostic arteriography was done in all cases. Intraoperative digital plethysmography aided in operative decisions regarding the necessity for microvascular reconstruction. Five aneurysms were resected with end-to-end ulnar artery microvascular repairs, four resected without repair, and a single case treated with long-term anticoagulants. Follow-up, averaging 40 months, showed uniform improvement in vascular symptoms, with no loss of jeopardized tissues. Ulnar artery aneurysms, well studied preoperatively and intraoperatively, can be treated successfully with selective microvascular reconstruction.

Adolescent↗
PubMed1990

Comparative bacterial clearances of muscle and skin/subcutaneous tissues with and without dead bone: a laboratory study.

Seventeen New Zealand White rabbits underwent implantation of three different concentrations of bacteria and a sterile saline control solution with and without dead autologous bone in eight separate muscular and eight separate subcutaneous sites. Following a period of 1 week, each site was surgically explored and samples of tissue were taken for histology and quantitative culture. Results reveal that final bacterial concentrations in the subcutaneous sites were significantly lower than in the muscle sites (p less than or equal to 0.0001) for each concentration of bacteria, with and without dead bone. Dead bone resulted in very significantly greater bacterial concentrations in both subcutaneous and muscle sites. Clinically, these results indicate that a thorough bony wound debridement is more important than the type of tissue used to close the wound. Flap tissue should be selected with regard to the perfusion, contour, and appearance of the recipient site.

Abscess↗
PubMed1990

The effect of epinephrine in local anesthesia on the survival of full- and split-thickness skin grafts: an experimental study.

The effect of local anesthesia containing epinephrine on the survival of split- and full-thickness skin grafts remains unclear. In this blinded study, Xylocaine with or without epinephrine was injected subdermally prior to harvesting of split-thickness and full-thickness skin grafts on the dorsum of rabbits. After procurement, the grafts were placed back into their original donor sites. Statistical analysis of graft survival 7 days postoperatively revealed a significant decrease in survival for the full-thickness skin grafts treated with Xylocaine with epinephrine as compared with similar grafts without epinephrine (p less than 0.0005). No significant difference was noted for split-thickness skin-graft survival in grafts treated with Xylocaine with and without epinephrine (p greater than 0.1).

Anesthesia, Local↗
PubMed1990

Retro-orbicularis oculus fat (ROOF) resection in aesthetic blepharoplasty: a 6-year study in 63 patients.

Sixty-three nonconsecutive patients have undergone resection of the retro-orbicularis oculus fat (ROOF) in conjunction with aesthetic blepharoplasty. In these patients, a consistent and useful ability to soften and flatten heaviness and bulkiness in the lateral upper orbital region was seen. Two patients developed postoperative hematoma, and two different patients had transient dry-eye symptoms following blepharoplasty. Twenty percent of patients had a transient degree of numbness in the lateral supraorbital nerve region, and all patients noted some transient numbness over the lateral upper brow region. No patient demonstrated significant paralysis of the orbicularis oculus or corrugator muscle. From this experience, retro-orbicularis oculus fat resection would appear to be a useful adjunct to standard blepharoplasty techniques in selected patients.

Adipose Tissue↗
PubMed1990

Flap failure after microvascular free-tissue transfer: the fate of a second attempt.

In most cases, the loss of a free-tissue transfer is a disaster for both the patient and the surgeon. Seven patients received a second microvascular free-tissue transfer after loss of the first. The indications for free-tissue transfer included chronic osteomyelitis of the lower leg (four patients), acute traumatic defect of the leg (one patient), acute traumatic defect of the arm (one patient), and esophageal defect after surgical excision (one patient). In three patients, the interval between the first and second procedures was less than 2 weeks. The remaining four patients had their second free-tissue transfer performed 5 weeks to 21 months after the first. Six of the seven free flaps were successful. Two patients with venous obstruction occurring after the second free-tissue transfer were salvaged by reexploration. Partial loss of the flap was noted in one of these patients. It is concluded from this select group of patients that failure of a free-tissue transfer does not contraindicate a second microtissue transfer does not contraindicate a second microvascular free-tissue transfer.

Adolescent↗