Images in clinical medicine. Transfer of a toe to the hand.
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Adult↗
Biomedical subjects
J W May
Publications and source records attributed to J W May.
Augmented Becker versus modified Kessler tenorrhaphy in monkeys: dynamic mechanical analysis.
The strength and gliding efficiency of an augmented Becker and Kessler tendon repair techniques were compared in fresh cadaver macaque monkey hands. Gliding efficiency was determined by comparing tendon work and load measurements made during tendon excursion to full fist with the same measurements made after tendon repair. Repair strength was then determined by tendon distraction to complete repair rupture. Data were gathered by computer controlled tensiometer and analyzed by factorial and repeated measures ANOVA. The augmented Becker repairs were significantly stronger than Kessler repairs. Repaired tendons required more load and work to bring the fingers into full fist; both repair types resulted in gliding efficiencies of 30% compared to intact controls. The augmented Becker repair is significantly stronger in situ than the modified Kessler and is recommended when early postoperative motion regimens are planned.
Analysis of Variance↗
The antithrombotic effects of ticlopidine and aspirin in a microvascular thrombogenic model.
In the effort to reduce a persistently significant failure rate in free tissue transfers and digital replantations, the efficacy of two oral platelet inhibitors, aspirin and ticlopidine, was examined using the arterial inversion graft, a known microvascular thrombogenic model. Forty male New Zealand White rabbits were used to create eighty 5-mm inversion grafts. Four groups were blindly given perioperative oral drug therapy: ticlopidine, aspirin, both, or neither (control). Vessel patency was evaluated at 1 hour and 1 week after surgery. The patency rate for the control group was 20 percent at 1 hour and 5 percent at 1 week. The drug-treated patency rates at 1 hour and 1 week, respectively, were 45 percent (p = 0.046) and 15 percent for ticlopidine, 35 percent and 10 percent for aspirin, and 45 percent (p = 0.046) and 20 percent for the combination therapy. This study shows that ticlopidine alone or in combination with aspirin significantly increases the 1-hour patency rates in a reliable thrombosis model, but it fails to show a significant increase in the final patency rates by either drug administered alone or in combination. The benefit in clinical microvascular surgery of either aspirin or ticlopidine is not determined by this study.
Administration, Oral↗
Hernia prevention and aesthetic contouring of the abdomen following TRAM flap breast reconstruction by the use of polypropylene mesh.
The value of synthetic mesh use in the treatment of recurrent abdominal hernias is well recognized and has led to its advocacy by some authors as an adjunct in primary hernia repair. Mesh use in the donor-site closure associated with TRAM flap reconstruction is typically restricted to situations where undue tension or questionable tissue integrity may be predisposing factors to herniation. Although more liberal use of mesh has been advocated for these circumstances, fear of mesh complications may continue to restrict its use. We present a series of 65 consecutive patients who had routine mesh application to fascial closures following TRAM flap breast reconstruction. The use of mesh provides an added margin of strength to fascial reconstruction and was found to have additional benefit as a technical adjunct to the aesthetic aspects of the abdominoplasty. Mean patient follow-up was 56.4 months. The resulting rates of hernia (1.5 percent) and mesh-related infection (1.5 percent) demonstrate its considerable safety. We recommend consideration of polypropylene mesh use for improved strength and aesthetic quality of the donor-site closure following TRAM flap breast reconstruction.
Abdomen↗
Effects of delay procedures on vasculature and survival of arterialized venous flaps: an experimental study in rabbits.
The effect of delay procedures on the survival of large arterialized venous flaps was studied in a rabbit ear model. Both ears of 25 New Zealand White rabbits (n = 50) were randomized into three operative groups receiving (1) no delay, (2) limited delay, or (3) extensive delay. Two weeks later the ear flap was completely divided, and arterialization of the flap venous tree was achieved by anastomosing the central artery of the ear to the anterior branch of the flap central vein. Survival area of 10 flaps in each group was assessed at 14 days. Flap vasculature was assessed in 10 additional ears in the nondelayed and extensively delayed groups by standardized vascular injections with radiopaque silicon rubber immediately, 6 hours, 24 hours, and 2 weeks after arterialization. Delay procedures significantly increased (p = 0.001, unpaired two-tailed Student's t test) survival of arterialized venous flaps in this model. Whereas all flaps in the non-delayed group underwent total necrosis, the mean viable surface area of the flaps was 67.9 percent in the limited delay group and 94.0 percent in the extensively delayed group. Lastly, angiographic studies suggest that delay procedures prior to arterialization of the venous tree enhance perfusion of the arterial tree by increasing venoarterial communications.
Angiography↗
Pattern of polar extension of the cell wall in the fission yeast Schizosaccharomyces pombe.
The indirect fluorescent-antibody technique has been used to establish the pattern of polar extension in the fission yeast Schizosaccharomyces pombe 160 over a complete cell cycle in liquid medium, thus avoiding the possibility of perturbations being introduced by growth on an agar pad, which is the technique used in most other investigations. Nearly all of the cells (about 98%) showed more growth at the old end than at the new end that was formed by cleavage of the septum at the previous division. Importantly, there was no evidence of the abnormal growth pattern (i.e., the significant contribution of new ends to extension) in cells of S. pombe growing on agar pads reported by Miyata et al. (H. Miyata, M. Miyata, and B.F. Johnson. 1986. Can. J. Microbiol. 32: 528-530 and 1990. Can. J. Microbiol. 36: 390-394). In addition, extension over the cycle was inversely related to birth length (cells shorter than the mean at birth tended to produce daughter cells longer than themselves and vice versa), there was a small but significant asymmetry in the position of the septum, and the time of initiation of extension at the new end was estimated at about 0.24 of the cycle.
Cell Division↗
Subciliary malar augmentation and cheek advancement: a 6-year study in 22 patients undergoing blepharoplasty.
Twenty-two patients seeking aesthetic improvement of their eyelid and orbital-cheek region underwent malar augmentation and cheek advancement in conjunction with lower eyelid blepharoplasty by means of a subciliary incision. The follow-up ranged from 12 to 78 months, with a mean follow-up of 44 months. Concomitant other aesthetic procedures were performed in 27 percent of the patients. Satisfactory goals of lower eyelid aesthetic improvement and malar augmentation with cheek advancement were achieved in 21 of 22 patients. A single patient had her implants removed within 3 weeks of her initial operation, at her request. Complications included hematoma formation in two patients, transient ectropion in two patients, and a palpable implant edge in a single patient. There were no long-term functional or aesthetic sequelae. Malar augmentation and cheek advancement have been found to be a significant adjunct to lower eyelid blepharoplasty because they improve the appearance of the cheek region and add a youthful contour to the malar area. These straightforward procedures add an effective dimension to blepharoplasty in appropriately selected patients.
Adult↗
Access to peri-implant pocket: a useful technique for local anesthetic administration or fluid drainage.
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Anesthesia, Local↗
Mechanical analysis of tendon suture techniques.
The relative strengths of seven methods of tendon repair were measured by mechanical disruption in an effort to determine the quality of a technique using loaded criss-crossing sutures and a running epitenon stitch. Fifty-seven calcaneus tendons were harvested from adult New Zealand white rabbits and randomized for transection. Standardized oblique transections were repaired with nylon using modified Halsted peripheral suture; modified Kessler technique; Kessler core stitch alone; running peripheral epitenon stitch; modified Becker technique #1; modified Becker technique #2; and a new augmented Becker repair. Sixteen additional rabbits each had bilateral tendon repairs in situ, one leg by Kessler and the other by the new augmented Becker repair technique. Half were lethally injected after 2 weeks and half after 4 weeks. Tenorrhaphies were pulled apart at constant speed until a gap of 1 mm was observed. Strength (maximum stress) and toughness (energy absorption to gap formation) were calculated. At time 0 the new augmented Becker repairs were the strongest, followed by the Kessler and Becker #2 tenorrhaphies. Kessler repairs were weaker at 2 weeks and then gained in strength; new augmented Becker repairs did not weaken at the 2-week point and demonstrated significant gains in strength after 4 weeks in vivo. The new augmented Becker repair was the strongest by a significant margin at all time points.
Animals↗
Smooth versus textured expander implants: a double-blind study of capsule quality and discomfort in simultaneous bilateral breast reconstruction patients.
Textured silicone expanders are alleged to be less painful in the filling process, to have less capsular contracture, and to stay in position better than smooth silicone expanders. To test these three hypotheses, 6 patients undergoing bilateral simultaneous expander implant placement for breast reconstruction after mastectomy were studied. In a double-blind fashion, after smooth and textured implant placement (one in each side) and initial wound healing, each patient was sequentially expanded with equal volumes of saline. In each patient, at each expansion, pressure data, discomfort scores, and implant placement measurements were made. At implant removal, smooth and textured capsule tissues were studied for collagen type content and ability to contract the patient's own fibroblast-populated collagen lattice. In 4 of 6 patients the smooth expander was associated with lower injection pressures and less discomfort. In all patients the expanders maintained their position, except in 1 patient whose smooth implant shifted laterally. The capsular collagen typing and fibroblast-populated collagen lattice studies demonstrated no difference between smooth and textured capsules. In this double-blind clinical study in simultaneous bilateral breast reconstruction patients we could not confirm the suggestion that textured silicone expanders produce less capsular contracture and cause less pain with injection.
Adult↗
Improved survival rates of random flaps in rabbits with a monoclonal antibody that blocks leukocyte adherence.
To examine the role of neutrophil adhesiveness in the tissue injury involving the ischemic "at risk" area of random flaps, we used the monoclonal antibody 60.3, which binds selectively to the primary neutrophil adherence-mediating glycoprotein CD18 in a random cutaneous flap model. Control animals that had flaps elevated and replaced (n = 12) had a mean distal necrosis of 31.9 +/- 9.3 percent of the total flap surface area. Treatment with monoclonal antibody 60.3 (n = 12) reduced distal necrosis to 10.6 +/- 7.5 percent (p < 0.005). Inhibiting inosculation by interposing a thin silicone sheet decreased distal flap survival; however, the protective effect of monoclonal antibody 60.3 on improving flap survival was unchanged. Control isolated flaps (n = 13) had a mean distal necrosis of 49.0 +/- 15.5 percent compared with 22.2 +/- 5.6 percent for the antibody-treated (n = 8) isolated flaps (p < 0.05). We conclude that increased neutrophil adhesiveness plays an important role in the tissue injury involving the ischemic "at risk" area of random flaps and the transient, specific inhibition of leukocyte adherence by monoclonal antibody 60.3 improves the distal survival of random flaps in this model. Moreover, we conclude that "graft inosculation" contributes to "flap" survival in this model; however, conclusions regarding the effect of treatment are not altered by blocking inosculation.
Animals↗
The capsule quality of saline-filled smooth silicone, textured silicone, and polyurethane implants in rabbits: a long-term study.
Recently, there have been many new designs in both the surface texture and chemical composition of breast implants that claim reduced constrictive capsular formation. The purpose of this study was to utilize a quantitative method to determine the firmness of capsules formed around saline-filled smooth silicone, textured silicone, and polyurethane implants in an experimental rabbit model 1 year after implantation. Our objective was to analyze the histologic, biologic, and biochemical content of the respective capsules to account for any differences in physical behavior. Forty-five smooth silicone, textured silicone, and polyurethane implants were placed in one of three positions beneath the panniculus carnosus muscle of New Zealand White rabbits. After 1 year, all capsules were palpated and classified according to firmness. Intracapsular static and dynamic pressure measurements were obtained by placing a pressure monitor (Stryker) in an injector port attached to the individual implants. Capsular firmness was significantly greater in the textured silicone implants than in the smooth silicone or polyurethane implants after 1 year. The dynamic qualities of the periprosthetic soft tissues were measured while saline was injected into the implants. The capsules around the textured silicone implants generated significantly higher pressures than the smooth silicone or polyurethane counterparts. The capsules around the polyurethane implants were the softest and most compliant in all categories. Histologically, there is a significant inflammatory response surrounding the textured silicone implants that does not exist in the capsules around the smooth silicone implants. The capsules around the polyurethane implants have the least fibrous tissue deposition. There is a decrease in the proportion of type III collagen in the capsules around the textured silicone implants versus smooth silicone or polyurethane implants. The in vitro contraction patterns of the fibroblast-populated collagen lattices do not reveal the contraction differences observed in vivo in rabbits. However, there are many components that determine contractility. This area deserves further investigation.
Animals↗
Reduction of burn injury by inhibiting CD18-mediated leukocyte adherence in rabbits.
The progressive nature of dermal ischemia and subsequent tissue destruction within the "zone of stasis" is a central focus in burn research. To examine the role of neutrophils and neutrophil adherence within the zone of stasis, we utilized the monoclonal antibody (MAb) 60.3, directed to the human leukocyte adherence glycoprotein CD18 to block neutrophil adherence to endothelium and intravascular aggregation in a rabbit model of partial-thickness burn. Burns were created by applying an 80 degrees C brass template to the dorsal rabbit skin for 5 or 10 seconds. Animals treated with MAb 60.3 thirty minutes following a 5-second burn had less edema, thinner eschar, and earlier elevation of the eschar than control animals. Histologic analysis revealed an eightfold increase in live hair follicles (p < 0.05) and 43 percent greater reepithelialization at 8 days (p < 0.05) and a 15 percent reduction in burn surface area at 24 hours (p < 0.0001) in the antibody-treated group. There was no significant difference between treatment and control groups exposed to 10-second burns. We conclude that neutrophils and increased neutrophil adherence play important roles in the progressive tissue destruction within the zone of stasis in burns. Furthermore, moderate burn injury may be significantly attenuated by blocking neutrophil adherence functions with a CD18 MAb.
Animals↗
Synthetic mesh. Its use in abdominal wall reconstruction after the TRAM.
This technique has evolved over 13 years and has been associated with very few mesh-related complications. A recently reported study of 65 consecutive patients with a mean follow-up of 47.4 months reported a hernia rate of 1.5% (1 of 65) and an incidence of mesh-related infection of 1.5% (1 of 65). It appears that the use of polypropylene (Marlex mesh) offers the reconstructive surgeon several advantages, including elevation of the entire rectus flap, thereby preserving the entire blood supply to the rectus muscle. Second, the interrupted suture technique surrounding the mesh allows for greater distribution of force and diminishes the risk of fascial dehiscence. Therefore, one can obtain a tighter, narrower abdomen to achieve an improved aesthetic abdominal result. The TRAM flap breast reconstruction should not only yield a fine reconstructed breast but also deliver an aesthetic abdominal contour improvement that represents a significant benefit to the patient undergoing this procedure.
Abdominal Muscles↗
Bacterial clearance capability of living skin equivalent, living dermal equivalent, saline dressing, and xenograft dressing in the rabbit.
Two new skin substitutes, Living Skin Equivalent (LSE) and Living Dermal Equivalent (DE), have recently been developed. In this experiment, the ability of the LSE and DE preparations to function as biological dressings in an acute wound model was tested. Forty full-thickness wounds were made in New Zealand White rabbits. Each wound was inoculated with 5 x 10(5) Staphylococcus aureus organisms. Twenty-four hours later, one of the following four dressings was applied: saline gauze, porcine-derived xenograft, LSE, or DE. Daily dressing changes and wound biopsies for bacterial counts were performed. At 96 hours after inoculation, split-thickness autograft was applied to all wounds. Skin graft take was assessed 5 days later. In all treatment groups, bacterial counts decreased over time (p = 0.02). At 72 and 96 hours after inoculation, wounds dressed with LSE or DE had significantly lower mean bacterial counts than wounds treated with xenograft dressing (p < 0.01). No significant differences were found among the LSE-, DE-, or saline-treated groups. Skin grafts took well in LSE- and DE-treated wounds. In conclusion, the LSE and DE were more effective than xenograft in reducing bacterial wound contamination in this model, thereby demonstrating their potential application as biological dressing materials.
Animals↗
The effect of dextran on microvascular thrombosis in an experimental rabbit model.
Although low molecular weight dextran is commonly utilized in clinical microsurgery, few experimental data are available documenting its efficacy. Bilateral 2-mm arterial inversion grafts were constructed in the femoral arteries of New Zealand White rabbits. The experimental group (n = 40 grafts) received a 5-day constant infusion of intravenous dextran 40 at 2.1 ml/hour, and the control group (n = 50 grafts) received no infusion. Whereas 85 percent (34/40) of the dextran grafts were patent at 1 week, only 48 percent (24/50) of the control grafts were patent (p = 0.0003). Scanning electron micrographs revealed a decrease in both platelet and fibrin deposition in the patent dextran arterial inversion grafts versus the patent control specimens. As a marked diminution in microvascular thrombosis was demonstrated at a clinically relevant dose, the continued use of intravenous dextran 40 in clinical microsurgery is supported by this study.
Animals↗
The effect of systemic antibiotic and antibiotic-impregnated polymethylmethacrylate beads on the bacterial clearance in wounds containing contaminated dead bone.
A dorsal muscular wound model was used in 40 New Zealand White rabbits to study the effect of systemic and local antibiotics on the bacterial clearance of contaminated dead bone. Devitalized iliac crest bone preincubated with Staphylococcus aureus was implanted in each deep muscular wound with or without tobramycin-impregnated polymethylmethacrylate beads. Either systemic tobramycin or cefazolin was administered for 7 days. Animals were sacrificed at 7 and 14 days. The wounds containing tobramycin beads had significantly fewer bacteria than those without antibiotic beads (2.0 x 10(2) versus 1.3 x 10(6); p < 0.008). The reduction in bacteria due to the tobramycin beads did not differ significantly with respect to the concurrent systemic antibiotics or to the duration of incubation. We conclude that tobramycin-impregnated beads are effective in reducing bacterial count in contaminated bony wounds treated with systemic antibiotics. Furthermore, the bactericidal effect of the antibiotic beads is independent of and additive to the systemic antibiotic delivered to the wounds by well-perfused muscles.
Animals↗