Treatment of recurrent neuroma of the interdigital nerve by implantation of the proximal nerve into muscle in the arch of the foot.

A prospective study was done to evaluate the results of treating recurrent "Morton's" neuroma by a technique that combined resecting the interdigital neuroma through a plantar approach and implantation of the proximal end of the nerve into an intrinsic muscle in the arch of the foot. As a part of this study, quantitative sensory testing was done for the medial plantar and medial calcaneal nerves. Seventeen recurrent interdigital neuromas were resected in 13 patients. Pain was identified on physical examination as being due to neuromas located in the first (one), second (six), third, (eight) and fourth (two) web spaces. Seven of the 13 patients were found to have, by quantitative sensory testing and physical examination, an associated tarsal tunnel syndrome responsible for symptoms related to numbness in the foot in addition to the pain of the recurrent neuroma. These patients had tarsal tunnel decompression at the time of the neuroma resection. At a mean follow-up time of 33.8 months (range 24-42 months), done by direct physician interview and examination, 80% of the patients had excellent relief of symptoms, returned to their regular job, and wore usual footwear. Twenty percent of the patients had good relief of symptoms, worked at a different job, and had to change their footwear. It is concluded that recurrent pain after a dorsal interdigital neurectomy can be treated successfully through a plantar approach with implantation of the proximal end of the nerve into an intrinsic muscle. This study also identified an association of tarsal tunnel syndrome in 54% of this series of patients with recurrent Morton's neuroma.

Retrobulbar hematoma and blepharoplasty.

Retrobulbar hematoma leading to visual impairment is a rare but serious complication associated with elective blepharoplasty. A review of the literature addressing etiology, prevention, and management is presented. Removal of anterior orbital fat associated with traction and rupture of vessels within posterior orbital fat is currently most strongly supported as the cause of retrobulbar hematoma after blepharoplasty. Optic nerve ischemia is identified as the likely cause of visual impairment. Specific recommendations for avoidance and management of acute retrobulbar hematoma are offered. Recent background animal and human research is summarized.

Control of hypertrophic scar growth using selective photothermolysis.

BACKGROUND AND OBJECTIVE: Previous studies have shown a clinical improvement of hypertrophic scars (HS) after treatment with a pulsed dye laser. The objective of this study was to investigate the effects of variations in pulse wavelength and energy density on HS tissue using human HS implanted in athymic mice. STUDY DESIGN/MATERIALS AND METHODS: Small pieces (approximately 1 mm3) of HS tissue were implanted into athymic mice and allowed to grow for 5 days. The implant site was then exposed to a single 450 microseconds pulse, and implant growth and histology were monitored for an additional 12 days. Laser wavelength and energy density ranges tested were 585-600 nm and 2-10 J/cm2, respectively. RESULTS: Using a wavelength of 585 nm, laser treatment inhibited implant growth by 70% at 6 J/cm2 and 92% at 10 J/cm2, respectively. The inhibitory effect decreased as the laser wavelength was increased from 585 to 600 nm. A widespread destruction of the implant microvasculature with a minor effect on surrounding extracellular matrix at the highest light dose were observed. CONCLUSION: Pulsed laser treatment inhibits HS implant growth in nude mice. This effect is likely mediated by selective photo-thermolysis of the implant microvasculature.

Control of hypertrophic scar growth using antibody-targeted photolysis.

Hypertrophic scar is marked by excess collagen accumulation secondary to an increased vascularization response in the scar and an increase in fibroblast cell density. It is currently the most debilitating long-term complication of the surviving burn patient, and at present, there is no routinely effective form of therapy. In this study, we investigated the potential use of antibody-targeted photolysis (ATPL) in treating hypertrophic scars. An immunoconjugate consisting of a photosensitizer (Sn-chlorin e6) linked to a monoclonal antibody that binds to human myofibroblasts (PR2D3) was prepared, which in response to photoactivation produces singlet oxygen in close proximity to the target cell surface. The model used for these studies consisted of 1-mm 3 human hypertrophic scar tissue implants in athymic mice. These implants increase approximately 20-fold in volume over a period of 15 days. Four days after implantation immunoconjugate was injected directly into scar implants allowed to diffuse throughout for 24 hr before implants were illuminated with laser light at 630 nm (120 J/cm 2). ATPL treatment caused a significant reduction in total growth compared to the untreated controls (P < 0.05). No effect was observed when an irrelevant conjugate (anti-Pseudomonas aeruginosa) was used. Histological examination of the ATPL-treated implants 24 hr post-ATPL revealed the presence of a large number of lipid droplets indicative of massive cell damage and infiltration by mononuclear cells and neutrophils.

Common virulence factors for bacterial pathogenicity in plants and animals.

A Pseudomonas aeruginosa strain (UCBPP-PA14) is infectious both in an Arabidopsis thaliana leaf infiltration model and in a mouse full-thickness skin burn model. UCBPP-PA14 exhibits ecotype specificity for Arabidopsis, causing a range of symptoms from none to severe in four different ecotypes. In the mouse model, UCBPP-PA14 is as lethal as other well-studied P. aeruginosa strains. Mutations in the UCBPP-PA14 toxA, plcS, and gacA genes resulted in a significant reduction in pathogenicity in both hosts, indicating that these genes encode virulence factors required for the full expression of pathogenicity in both plants and animals.

The beneficial effect of dextran on anastomotic patency and flap survival in a strongly thrombogenic model.

Dextran lowers the probability of thrombus formation, by reducing platelet aggregation and adhesion and by increasing fibrinolysis. All studies to date using dextran for microvascular reconstruction have examined only short-term (1 to 2 hr) patency in isolated vessels. The current study used an established thrombotic model (inverted sleeve interposition graft), to investigate the effect of dextran on the long-term survival of pedicle flaps. A6- x 3-cm epigastric flap was elevated. A 2-mm inverted sleeve interposition graft was placed on the artery side of the pedicle by microvascular techniques. One group received dextran (17 cc/kg) 2 hr preoperatively and every 6 hr postoperatively for the next 72 hr. A control group received saline on the same schedule. Survival was assessed on postoperative day 7, at which time necrosis was obvious. Several parameters (clotting studies and electron microscopy) were studied to characterize the phenomenon more clearly. Only 25 percent of saline-treated flaps survived (2/8), while all dextran-treated flaps survived (7/7) (p less than 0.02, Fisher exact test). Thus, dextran allowed flaps to survive by preventing thrombus formation, despite a strong thrombogenic focus.

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).

Prognosis and survival as determined by visceral amino acid clearance in severe trauma.

Sepsis, the commonest cause of late death following severe trauma, is related in part to inadequate uptake of amino acids (AA) and synthesis by the liver and other central tissues of proteins essential to immunological defense. Since 'central plasma clearance rate' of amino acids (CPCR-AA) has been found to reflect these functions, serial measurements of CPCR-AA were made in 32 seriously injured patients of whom ten died (31%), nine of sepsis. The mean Index Severity Score on admission for survivors was 31 +/- 1.8 and in deaths 34 +/- 3.9 (N.S.). The blood plasma AA concentrations were not significantly different. However, early in the course before the onset of infection, CPCR-AA in surviving patients was 227 +/- 30 and in those who ultimately died 83 +/- 24 ml/M2/min (p less than 0.001). Later during sepsis the values of CPCR-AA were 176 +/- 28 and 85 +/- 14 ml/M2/min, respectively (p less than 0.01). Thus CPCR-AA appears to be of value as an indicator of amino acid utilization by central tissues and as a predictor of survival or death following severe trauma.