Oren Shoshani

The Effect of Interleukin-8 on the Viability of Injected Adipose Tissue in Nude Mice

Adipose tissue injection as a free graft for the correction of soft-tissue defects is a widespread procedure in plastic surgery. The main problem in achieving long-term soft-tissue augmentation is partial absorption of the injected fat and hence the need for overcorrection and re-injection. The purpose of this study was to improve the viability of the injected fat by the use of interleukin-8. The rationale for the use of interleukin-8 was its abilities to accelerate angiogenesis and attract inflammatory cells and fibroblasts, providing the injected adipocytes more feeding vessels and a well-established graft bed to enhance their viability. Human adipose tissue, obtained by suction-assisted lipectomy, was re-injected into the subcutis in the scalp of nude mice. Interleukin-8 (0.25 ng) was injected subcutaneously to the scalp as a preparation of the recipient site 24 hours before the fat injection and was added to the fat graft itself (25 ng per 1 cc of injected fat). In the control group, pure fat without interleukin-8 was injected and no interleukin-8 was added for the preparation of the recipient site. One cubic centimeter of fat was injected in each animal in both the study and control groups. There were 10 animals in each group. The animals were euthanized 15 weeks after the procedure. Graft weight and volume were measured and histologic evaluation was performed. In addition, triglyceride content and adipose cell sizes were measured as parameters for fat cells viability. Histologic analysis demonstrated significantly less cyst formation in the group treated with interleukin-8. No significant differences were found between the groups with regard to graft weight and volume or the other histologic parameters investigated. No significant differences were demonstrated in adipose cell sizes and their triglyceride content. In conclusion, less cyst formation, indicating improved quality of the injected fat, can be obtained by the addition of interleukin-8. Further studies of various dosages of interleukin-8 and their long-term effect are required before these encouraging results could be applied clinically.

Viability of adipose tissue injected and treated by different methods: an experimental study in the rat.

Fat injection is being used for the correction of various soft-tissue defects. In this study, the manner of fat injection yielding the greatest transplant viability was examined. Autologous fat was obtained from the inguinal area of rats and subsequently reinjected to the nuchal region, an area naturally poor in subcutaneous fat. Before injection, the fat was processed by one or more of the following methods: suture of the recipient area, repeated washing to remove residual blood, and addition of insulin. Transplant status was evaluated by both macroscopic and microscopic examination of the recipient sites 2 weeks and 12 weeks after the injection. The results demonstrated that the injected fat remained in part as viable new fatty tissue in the nuchal area. No statistically significant improvement in the viability of the injection fat was noticed at 2 weeks and 12 weeks after its processing by the different methods just described. Significant positive correlation was demonstrated between the volume of the injected fat and the size of the bulging at the injection area only 2 weeks after the injection.

The effect of hyperbaric oxygenation on the viability of human fat injected into nude mice.

&NA; Autologous free‐fat injection for the correction of softtissue defects has become a common procedure in plastic surgery. The main shortcoming of this method for achieving permanent soft‐tissue augmentation is the partial absorption of the injected fat, an occurrence that leads to the need for both overcorrection and repeated fat reinjection. Improving the oxygenation of the injected fat has been suggested as a means of helping to overcome the initial critical phase that occurs postinjection (when the fat cells are nourished by osmosis), increasing phagocyte activity, accelerating fibroblast activity and collagen formation, and enhancing angiogenesis. In addition, the hyperbaric oxygen‐mediated decrement in endothelial leukocyte adhesion will decrease cytokine release, thereby reducing edema and inflammatory responses. The purpose of the present study was to examine the effect of hyperbaric oxygenation on improving the viability of injected fat. Adipose tissue obtained from human breasts by suctionassisted lipectomy was injected into the subcuticular nuchal region in nude mice. The mice were then exposed to daily hyperbaric oxygen treatments, breathing 100% oxygen at 2 atmospheres absolute (ATA) for 90 minutes. The duration of the administered hyperbaric oxygen therapy was 5, 10, or 15 days, according to the study group. Mice exposed to normobaric air alone served as the control group, and each group included 10 animals. The rats were killed 15 weeks after fat injection. The grafts were dissected out, weight and volume were measured, and histologic evaluation was performed. In all of the study groups, at least part of the injected fat survived, giving the desired clinical outcome. No significant differences could be found between the groups regarding fat weight and volume. Histopathologic examination of the dissected grafts demonstrated a significantly better integrity of the fat tissue in the group that received hyperbaric oxygen for 5 days (p = 0.047). This finding was manifested by the presence of well‐organized, intact fat cells, along with a normal appearance of the fibrous septa and blood vessels. The worst results were found in animals treated by hyperbaric oxygenation for 15 consecutive days. An inverse correlation was found between an increased dose of the high‐pressure oxygen and fat tissue integrity (r= ‐ 0.87, p = 0.076). The toxic effects of highly reactive oxygen species on fat cells might explain the failure of an excessively high dose of hyperbaric oxygen to provide any beneficial outcome. The clinical relevance of these results should be further investigated. (Plast. Reconstr. Surg. 106: 1390, 2000.)

Hair removal using intense pulsed light (EpiLight): patient satisfaction, our experience, and literature review.

Applications for intense pulsed light (IPL) for hair removal are gaining favor among other methods, including lasers, because of its noninvasive nature, versatility regarding different skin and hair types, safety, and ease of use. Hair removal using IPL was performed from January 2002 to December 2003 on 108 consecutive patients. Eighty of these patients answered a questionnaire and were enrolled in the study group. The investigated parameters were hair and skin type, number of pulses, fluence, pulse duration, pulse delay, the filters used, and the treated area. The patient assessment of improvement (satisfaction) rate was graded from 1 to 5 points: 1, worse; 2, no improvement; 3, mild improvement; 4, good result; and 5, excellent result. The patients had between 1 and 13 treatments most of them during 2 to 6 sessions. Sixty-seven percent of the patients reported no complications. Prolonged erythema for more than 7 days was reported by 16.25%, blisters by 6.25%, temporary hyperpigmentation by 8.75%, leukotrichia was present in 1 case, and 1 case of persistent hypopigmentation was noted in a young girl. An increased number of complications and a decreased satisfaction rate were noted with higher skin types, but it was not statistically significant. Patients who underwent fewer treatments (1–3 treatments) were more satisfied compared with those who had more than 7 treatments (P < 0.02). Sixty percent of the patients rated their satisfaction to be good to excellent and 65% would ill recommend this treatment to their friends. To minimize the complication rate the authors found that the preset parameters should be adjusted at every treatment session according to the skin response at the previous one. Permanent hair removal cannot be guaranteed and it is not possible to predict the improvement rate. Nevertheless, based on patient satisfaction rate in this study, the authors recommend using IPL for hair removal.

Performance of Infusion Pumps during Hyperbaric Conditions

Background Many hyperbaric facilities use infusion pumps inside the chamber. It is therefore important to ensure that this equipment will perform accurately during hyperbaric conditions. The authors tested the function and accuracy of the Imed 965 and Infutec 520 volumetric infusion pumps, the Easy-pump MZ-257 peristaltic infusion pump, and the Graseby 3100 syringe pump. Methods The authors calculated the deviations of infused volumes at low and high rates (12–18 and 60–100 ml/h) on three different hyperbaric protocols (up to 2.5, 2.8, and 6 atmospheres absolute [ATA]), resembling a standard hyperbaric oxygen treatment and US Navy treatment tables used for decompression illness and for arterial gas embolism. Two examples of each pump model were examined in every experiment. Results The Easy-pump MZ-257 failed to function completely beyond a chamber pressure of 1.4 ATA, making it unsuitable for use inside the hyperbaric chamber. The Graseby 3100 failed to respond to all keyboard functions at 2.5–2.8 ATA, making it unsuitable for use in most hyperbaric treatments. The Imed 965 performed within an acceptable volume deviation (≤10%) during most hyperbaric conditions. During the compression phase of the profiles used, and for the low infusion rates only, exceptional volume deviations of 20–40% were monitored. The Infutec 520 demonstrated an acceptable deviation (within 10%) throughout all the hyperbaric profiles used, unaffected by changes in ambient pressure or infusion rate. Conclusions Commercially available infusion pumps operating during hyperbaric conditions demonstrate substantial variations in performance and accuracy. It is therefore important that the hyperbaric facility staff make a careful examination of such instruments to anticipate possible deviations in the accuracy of the equipment during use.

Effect of hyperbaric oxygen on a rat transverse rectus abdominis myocutaneous flap model

&NA; The single‐pedicle transverse rectus abdominis myocutaneous (TRAM) flap is frequently associated with partial flap necrosis. Hyperbaric oxygen has previously been shown to increase the survival of skin flaps, although there has been no investigation of possible beneficial effects of hyperbaric oxygen on survival of the TRAM flap. The present study compares the effectiveness of hyperbaric oxygen therapy, normobaric 100% oxygen, a hyperbaric air‐equivalent mixture, and no treatment at all (control group), in the prevention of TRAM flap necrosis in a rat model. Forty‐eight animals were randomly assigned to one of the four above‐mentioned groups. The surviving area of the flap was evaluated 7 days after surgery. The hyperbaric oxygen treatment protocol consisted of five 9‐minute sessions breathing 100% oxygen at a pressure of 2.5 atmospheres absolute during the first 48 hours, starting within 1 hour of surgery. The areas of surviving skin paddles ranged from 38.5 percent in the control group to 52.5 percent in the group treated with hyperbaric oxygen. One‐way analysis of variance indicated that flap area survival was significantly greater in the hyperbaric oxygen group (F = 2.69, p = 0.05). Tukeys pairwise comparison and the two‐sample t test indicated that the group treated with hyperbaric oxygen differed significantly from the control group (Tukeys critical value = 3.8, rejection level = 0.05, t test p = 0.01). Our results suggest that the hyperbaric oxygen treatment protocol used improves survival in the rat TRAM flap. However, the optimal treatment protocol to achieve this objective even in the rat seems to be variable, and further studies are required before extrapolating these data to human applications. (Plast. Reconstr. Surg. 102: 416, 1998.)

Contralateral Internal Mammary Silicone Lymphadenopathy Imitates Breast Cancer Metastasis

This case report presents a unique, late complication of breast reconstruction surgery. A woman, who underwent left mastectomy and several reconstruction procedures with silicone implants presented with symptomatic enlarged internal mammary lymph nodes on her contralateral side. The nodes, which were suspicious for breast cancer metastasis on positron-emission tomographic computed tomography, were removed by thoracoscopy. The histopathologic result revealed silicone adenopathy. This report is particularly interesting because it presents a rare case in which silicone has migrated to the contralateral internal mammary nodes. This complication was not previously documented in the medical literature and serves as a possible differential diagnosis to metastatic breast cancer.

Effect of hyperbaric oxygen on survival of composite grafts in rats

Most treatment with hyperbaric oxygen (HBO) in plastic surgery is for wounds, burns, crush injuries, and infections. We aimed to find out if HBO increases the survival of composite grafts in rats. Twenty Sprague-Dawley rats were randomly assigned to two equal groups (treatment and control). A template 30×30 mm was placed on the skin and a composite graft taken from the upper back was harvested and then resutured to the fascia in situ. The treated group was placed in a hyperbaric chamber set at 202 kPa and 100% oxygen for 90 minutes daily for two weeks. Control animals were given no treatment. After death the mean surviving internal surface area of the graft was 372.5 (117.9) mm2 in the control group and 561.3 (85.7) mm2 in the experimental group (p=0.001). Treatment with HBO improved the surviving area of composite grafts in rats, and the beneficial effect was prominent only on the inner surface of the graft.