Matthew J. Concannon

Analysis of lipocyte viability after liposuction.

Free fat grafts from liposuction aspirate can be used as donor material for soft-tissue augmentation. The purpose of this study was to attempt to identify a subpopulation of adipose cells within liposuction aspirate with the greatest viability and, it is hoped, a greater chance for increased survival after transplantation. Liposuction samples were obtained from 20 individuals (16 women, four men; age range, 27 to 49 years). These samples were then centrifuged at 50 g. At 2-minute intervals, specimens from three different areas (superficial, middle, deep) were obtained from each specimen. After collagenase degradation, the specimens were stained with trypan blue, and the number of viable cells were counted. The bottom (deepest) layer consistently contained the highest number of viable cells after centrifugation: 250 percent more viable cells when compared with the top layer (p < 0.0001) and 140 percent more viable cells when compared with the middle layer (p < 0.0002). Centrifugation beyond 2 minutes did not increase the number or proportion of viable adipocytes. When using aspirated fat from liposuction for soft-tissue augmentation, centrifugation for 2 minutes at 50 g will stratify the adipocytes, with more viable cells being found at the deepest layer. Using only this bottom portion of the fat layer for transplantation will yield a fat graft with a greater number of viable adipocytes, potentially improving fat graft survival and decreased fat graft resorption.

The predictive value of electrodiagnostic studies in carpal tunnel syndrome

&NA; In recent years, electrodiagnostic studies have become an expected component in the work up and evaluation of carpal tunnel syndrome. We conducted a retrospective review of 460 carpal tunnel decompressions to determine whether the accuracy of diagnosis and the prediction of therapeutic outcome could be related to the positivity and severity of findings on preoperative electrical studies. The 349 patients (460 hands) were divided into two groups: group 1 consisted of hands with the clinical diagnosis of carpal tunnel syndrome but with normal electrodiagnostic studies (n = 62); in group 2 the hands had a clinical diagnosis of carpal tunnel syndrome with confirmatory electrodiagnostic studies (n = 398). The number and distribution of signs and symptoms of carpal tunnel syndrome were not statistically different between these two groups. There was not a statistically significant difference in the success rate of surgery or the incidence of complications. The similarities between these two groups suggests that the distinction between them (the positivity of electrodiagnostic studies) is an artificial one and that the clinical diagnosis of carpal tunnel syndrome is sufficient to predict the presence of the disease, as well as outcome of surgery. On the basis of these data, strict adherence to electrodiagnostic studies to confirm the diagnosis will exclude 13 percent of the patients with legitimate carpal tunnel syndrome from receiving appropriate therapy. (Plast. Reconstr. Surg. 100: 1452, 1997.)

The incidence of recurrence after endoscopic carpal tunnel release

&NA; Endoscopic carpal tunnel release has been used to decompress the median nerve in carpal tunnel syndrome for over the past decade, with an advantage (over the traditional “open” release) being decreased pain in the postoperative period. The goals of this study were to attempt to define the recurrence rate after endoscopic carpal tunnel release and to determine if it differs from that of open technique. The charts of 191 consecutive carpal tunnel syndrome patients treated operatively at the University of Missouri were reviewed. For this study, recurrent carpal tunnel syndrome was defined as documented cases in which the symptoms had resolved following surgical release but subsequently recurred, requiring surgical rerelease of the carpal tunnel. All endoscopic releases were performed using the Chow two‐portal technique. Statistical analysis was performed using Fishers exact test. A total of 103 patient hands had open carpal tunnel releases; 88 were endoscopically released. Total follow‐up time (from the initial release) averaged 29 months for the open group and 22 months for the endoscopic group. There were no recurrences in the open group and six recurrences in the endoscopic group (7 percent, p = 0.008). All six recurrences were in workers compensation patients. The median time between endoscopic release and rerelease was 8.5 months. There seems to be a statistically higher incidence of recurrence of carpal tunnel syndrome after endoscopic release compared with the traditional “open” release in our cases. Although the pathogenesis of this increased rate of recurrence is not clear, this should be considered when planning surgical release of the volar carpal ligament for carpal tunnel syndrome. (Plast. Reconstr. Surg. 105: 1662, 2000.)

The effect of herbal medicines on platelet function: an in vivo experiment and review of the literature.

Background: Herbal medicines are used by a considerable number of surgical patients. An increased risk of bleeding, substantiated by anecdotal reports, has been attributed to the use of certain herbs, and numerous in vitro experiments have identified some herbal extracts as platelet inhibitors. The purpose of this investigation was to determine whether standard commercial preparations of commonly used herbal medicines have an effect on platelet function in vivo and, by extension, to provide clinical scientific evidence of the safety of their use in the perioperative period. Methods: Five commercially available herbal agents were investigated, including Ginkgo biloba, garlic, Asian ginseng, St. John’s wort, and saw palmetto. In a blinded fashion, one of the agents was administered to 10 adult volunteers at the manufacturer’s recommended dose for 2 weeks. At the end of the 2-week period, in vivo platelet function was quantified using the PFA-100 assay. After a 2-week “washout” period, the protocol was repeated using a different agent. This 4-week cycle was repeated for each of the five herbal agents, as well as the control agent aspirin. Results: In vivo platelet function was not affected by the administration of any herbal agent and was markedly inhibited with the administration of aspirin. Conclusions: The herbal medicines investigated in this study do not affect platelet function in vivo. Neither this experiment nor a review of the literature supports the concern of perioperative bleeding in users of these herbal medicines.

A critical look at capsule contracture in subglandular versus subpectoral mammary augmentation.

A critical comparison of the contracture rate in subglandular versus subpectoral augmentations was done in a personal series (senior authors) of 100 consecutive augmentation patients, 50 with subglandular augmentation and 50 with subpectoral augmentation. The average followup for the series was 27 months. Bakers classification of capsule contracture was utilized. Overall contracture rate in the subglandular group was 58% (29 of 50 patients) while in the subpectoral group it was 22% (11 of 50 patients),p<0.0002. Considering only the more severe contractures (Baker III & IV), the subglandular patients had 48% (24/50) while the subpectoral patients had 14% (7/50),p<0.0002. Comparing the more severe contractures in individual breasts, the subglandular group had 41% and the subpectoral group had 8%,p<0.0001. We conclude that in this personal series of patients, subpectoral placement of the prosthesis has significantly reduced but not eliminated the occurrence of capsule contracture without sacrificing a normal breast appearance.

Augmenting the narrow-based breast: The unfurling technique to prevent the double-bubble deformity

Routine subpectoral or subglandular mammary augmentation in women with a small breast (particularly lower pole deficiency) often results in poor late results with the appearance of a double-bubble deformity. We describe our experience with a technique of unfurling the breast tissue at augmentation in an effort to avoid this complication and improve the long-term results.

Patterns of free-radical production after tourniquet ischemia : Implications for the hand surgeon

Since use of the pneumatic tourniquet is standard procedure for the hand surgeon, ischemic and reperfusion injury is a risk. To determine optimal periods of ischemia, 100 rabbit hindlimbs were subjected to various ischemic insults and analyzed for malondialdehyde (an indicator of free-radical production). Group 1 (3 hours of continuous ischemia) had 12.5 percent more reperfusion damage than controls (p < 0.05). Group 2 (three 1-hour ischemic insults) had 10 percent more damage than controls (p < 0.05). Group 3 (two 90-minute ischemic episodes) had 21 percent more damage than controls (p = 0.0001). Group 4 (4 1/2 hours of continuous ischemia) had 14.5 percent more damage than controls (p < 0.01). Group 5 (three 90-minute ischemic episodes) had 10.8 percent more damage than controls (p < 0.01). Group 6 (6 hours of continuous ischemia) had 17.5 percent more damage than controls (p < 0.002). Group 7 (four 90-minute ischemic episodes) had 14 percent more damage than controls (p < 0.01). Group 8 (three 2-hour ischemic episodes) had 22.5 percent more damage than controls (p < 0.003). And group 9 (two 3-hour ischemic episodes) had 42 percent more damage than controls (p < 0.0001). These results suggest a direct correlation in reperfusion injury with duration of tourniquet ischemia. Additionally, allowing specific reperfusion periods in some groups ultimately increased the amount of reperfusion injury.

Is there liability with chemotherapy following immediate breast reconstruction

&NA; Review of 46 consecutive patients undergoing immediate breast reconstruction with tissue expanders and subsequent implant placement was conducted to assess the potential liability of adjuvant chemotherapy. Twenty‐three patients required chemotherapy, while 23 did not. Critical comparison of complications and outcome of the two groups revealed no significant differences. Within the parameters of this study (avoidance of expansion or surgery during the period of chemotherapy), there appeared to be no disadvantage posed to the immediate reconstruction patient by adjuvant chemotherapy. We feel that this option can continue to be offered despite the anticipation of probable chemotherapy. (Plast. Reconstr. Surg. 97: 9691, 1996.)

Digital images in the diagnosis of wound healing problems

The use of digital wound images could allow remote consultation among patients, physicians, or other care-givers located at quite distant sites by means of the Internet. To evaluate the efficacy and validity of digital images for the evaluation of wounds, the ability and reliability of surgeons to diagnose and make treatment suggestions using digital images of several types of wounds were compared. Twenty-four wound images on 35-mm slides were selected for use in this study. Each slide image was digitized at 24-bit color with a resolution of 640 pixels horizontal by 425 pixels vertical and stored as a JPEG file. These images were then presented as a slide show on a video monitor, with resolution set at 640 x 480. Six physicians examined the images, first in digital format and later in the original slide form. Each observer assessed each wound and possible treatment options by filling out a questionnaire using a series of yes/no questions. For all observers, there was an 87 percent agreement between digital and slide images (p = 0.004). The agreement between the digital and slide images was measured for each individual observer using a kappa coefficient. The agreement level corresponded to the experience of the observer, with the kappa values ranging from greater than 0.8 (almost perfect agreement) for the attending plastic surgeon to just greater than 0.5 (moderate agreement) for the intern. With this study, the feasibility of distance wound consultation using digital images of a quality consistent with consumer-grade digital photography was demonstrated.

Microsurgical replantation of an ear in a child without venous repair.

Ear amputation can leave a devastating deformity; the application of microsurgical replantation techniques has allowed very favorable aesthetic outcomes when successful. We report a case of ear replantation in a child in whom a venous repair was not performed; instead medicinal leeches were used to decompress the ear in the immediate postoperative setting. This represents the third reported case of successful ear replantation without microsurgical venous anastomosis. A review of the literature reveals the high incidence of venous congestion requiring external decompression (57 percent) and the very high rate of salvage (80 percent) after replantation. Surgeons attempting ear replantation should be aware of the high rate of ear survival in the situation of no venous outflow (with appropriate decompression techniques) and should not abandon attempts at replantation because of the inability to establish venous outflow microsurgically.