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Biomedical subjects

Spencer A Brown

Publications and source records attributed to Spencer A Brown.

At least 19 recordsLinked to original sources
PubMed2006

Platelet gel sealant use in rhytidectomy.

BACKGROUND: A prospective study was used to evaluate the efficacy of a commercially available platelet gel product as a sealant to decrease postsurgical drain fluid rates and volumes in patients who have undergone rhytidectomy procedures. Quantitative assessments of postoperative drain fluid outputs were compared in subjects who did and did not receive platelet gel treatment. METHODS: Autologous platelet concentrate was prepared from each subject (n = 19), combined with bovine thrombin to form a platelet gel, and applied during the rhytidectomy procedure. Surgical drains were placed and effluent was collected postoperatively at 8-hour intervals for 24 hours and the volumes were recorded. A retrospective examination of surgical drain output over time in subjects (n = 14) who did not receive platelet gel treatment was performed; this group served as the control group. RESULTS: Subjects who received the platelet gel sealant treatment had significantly decreased surgical drain fluid levels over 24 hours [109 +/- 8.5 ml (mean +/- SEM)] compared with subjects who did not receive the platelet gel sealant (78 +/- 7.5 ml) (p < 0.02). From 0 to 8 hours postoperatively, platelet gel-treated subjects had a mean 35 percent decrease in fluid levels compared with the controls (p < 0.03). No difference in surgical drain outputs was observed from 8 to 16 hours between the two experimental groups. From 16 to 24 hours, the control group had increased mean fluid levels (20 percent) and the platelet gel sealant group output levels decreased (50 percent). CONCLUSIONS: Platelet gel sealant treatment was associated with decreased surgical fluid drain output in the first 24 hours postoperatively.

Drainage↗
PubMed2006

Fluid resuscitation in liposuction: a retrospective review of 89 consecutive patients.

BACKGROUND: In 1998, the senior author presented the intraoperative fluid ratio, defined as the volume of super-wet solution and intraoperative intravenous fluid divided by the aspiration volume, to guide resuscitation fluid volumes in super-wet liposuction. The senior author demonstrated that intraoperative fluid ratios of 2.1 for small-volume and 1.4 for large-volume liposuction were safe and did not cause volume overload sequelae. A high urine output was common and reflected a mild overresuscitation, which could have adverse consequences in patients with undiagnosed cardiopulmonary disease. The purpose of this study was to compare overresuscitation sequelae in a cohort of consecutive super-wet liposuction patients using a new fluid management formula in which replacement fluid was given after 5000 cc of lipoaspirate instead of 4000 cc, as initially described. METHODS: The charts of 89 consecutive patients undergoing super-wet liposuction were retrospectively reviewed. RESULTS: The intraoperative fluid ratio was 1.8 for the small-volume reductions (< 5000 cc, n = 68) and 1.2 (> 5001 cc, n = 21) for the large-volume reductions. There were no episodes of pulmonary edema, congestive heart failure exacerbation, or other major complications. The average urine output in the operating room, the recovery room, and while on the floor was 1.5, 1.6, and 2.9 cc/kg/hour for the small-volume group and 1.7, 1.8, and 2.5 cc/kg/hour for the large-volume group. CONCLUSIONS: The super-wet subcutaneous infiltration liposuction technique for both small- and large-volume reductions is safe and can be performed without adverse cardiopulmonary sequelae. Given the high urine outputs, the intraoperative fluid ratio can be further improved by possibly eliminating the replacement fluid altogether.

Fluid Therapy↗
PubMed2006

A rabbit model for capsular contracture: development and clinical implications.

BACKGROUND: Capsular contracture remains one of the most common complications involving aesthetic and reconstructive breast surgery; however, its cause, prevention, and treatment remain to be fully elucidated. Presently, there is no accurate and reproducible pathologic in vitro or in vivo model examining capsular contracture. The purpose of this study was to establish an effective pathologic capsular contracture animal model that mimics the formation of capsular contracture response in humans. METHODS: New Zealand White rabbits (n = 32) were subdivided into experimental (n = 16) and control groups (n = 16). Each subgroup underwent placement of smooth saline mini implants (30 cc) beneath the panniculus carnosus in the dorsal region of the back. In addition, the experimental group underwent instillation of fibrin glue into the implant pocket as a capsular contracture-inducing agent. Rabbits were euthanized from 2 to 8 weeks after the procedure. Before the animals were euthanized, each implant was serially inflated with saline and a pressure-volume curve was developed using a Stryker device to assess the degree of contracture. Representative capsule samples were collected and histologically examined. Normal and contracted human capsular tissue samples were also collected from patients undergoing breast implant revision and replacement procedures. Tissue samples were assessed histologically. RESULTS: Pressure-volume curves demonstrated a statistically significantly increased intracapsular pressure in the experimental group compared with the control group. The experimental subgroup had thicker, less transparent capsules than the control group. Histologic evaluation of the rabbit capsule was similar to that of the human capsule for the control and experimental subgroups. CONCLUSIONS: The authors conclude that pathologic capsular contracture can be reliably induced in the rabbit. This animal model provides the framework for future investigations testing the effects of various systemic or local agents on reduction of capsular contracture.

Animals↗
PubMed2006

Autologous human fat grafting: effect of harvesting and preparation techniques on adipocyte graft survival.

BACKGROUND: Autogenous fat transfer with lipoinjection for soft-tissue augmentation is a commonly used technique without a universally accepted approach. The high percentage and variable amount of fat resorption reduce the clinical efficacy of this procedure and often result in the need for further grafting. The purposes of this study were to evaluate the effect of different harvesting and preparation techniques on human fat tissue viability and to determine fat tissue viability rates among the different fat preparations transplanted into a severe combined immune deficiency mouse model at 3 months. METHODS: Using standard liposuction and syringe aspiration, fat was removed from patients (n = 3) undergoing elective body contouring. Tissue was prepared by six different combinations of centrifugation and/or washing the cells with lactated Ringer's solution or normal saline. Metabolic activities of fat cell viability were monitored to assess overall cell viability. To analyze viability over 3 months, freshly harvested tissue specimens (minimum n = 5) were prepared by a combination of various procedures (wash, centrifugation, and different solutions) and subsequently injected under the dorsal flank skin of severe combined immune deficiency mice in two experiments. Mice were monitored for 12 weeks and the fat xenografts were removed for mass and histological evaluations. RESULTS: Metabolic analyses showed improved cell viability in tissue specimens undergoing minimal manipulation. No significant differences in fat cell viability, as assessed by graft weight maintenance or histologic evaluations, were observed with regard to harvesting or preparation techniques. CONCLUSIONS: Improved viability of freshly harvested but untreated fat specimens may be expected as compared with grafts that have undergone additional manipulations. No unique combination of preparation or harvesting techniques appeared to be more advantageous on transplanted fat grafts at 3 months. This study also demonstrated a reliable animal model for future investigation into examining novel applications for augmenting fat graft survival.

Adipocytes↗
PubMed2006

Lifestyle outcomes, satisfaction, and attitudes of patients after liposuction: a Dallas experience.

BACKGROUND: Liposuction is the most common cosmetic operation performed. To the authors' knowledge, no report has examined patients' attitudes and postoperative opinions, lifestyle changes, weight gain changes, and satisfaction with their liposuction procedure in general and by specific site. The authors report on data from a survey provided to patients by two plastic surgeons at the University of Texas Southwestern Medical Center at Dallas. METHODS: Six hundred questionnaires were mailed to all patients who had liposuction surgery performed between 1999 and 2003. There were 108 undeliverable surveys; 209 completed surveys were returned (34.8 percent of 600 and 42.5 percent of 492 surveys). Data were analyzed using the chi-square test. A p value of less than 0.05 was considered significant. RESULTS: The majority of patients (80 percent) were satisfied with their results. Fifty-three percent thought that their appearance was either "excellent" or "very good." With regard to satisfaction by site treated, 60 percent or more of the responders were "very satisfied" or "satisfied" with their results. Weight gain was reported in 43 percent of the responders, with 56 percent of them gaining between 5 and 10 pounds 6 months after their surgery. Fat return was reported in 65 percent of the responders. The abdomen was the most common location for fat return. As a group, 79.7 percent would have the procedure again and 86 percent would recommend the procedure to family or friends. Approximately 75 percent of responders described their postoperative discomfort as mild to moderate, with 60 percent indicating that their discomfort lasted less than 7 days (39.8 percent indicated their pain lasted longer than 7 days); 83 percent indicated that they only needed to use narcotics for 7 days of less. When responders were divided into groups, the great majority of patients were satisfied with the surgery and their results. CONCLUSIONS: Despite postoperative pain, fat return, and weight gain, patients were willing to have the procedure again and recommend it to others. Those patients who were unsatisfied and were less likely to refer patients were those who had the lowest opinion of their appearance.

Abdomen↗
PubMed2006

Defining vascular supply and territory of thinned perforator flaps: Part II. Superior gluteal artery perforator flap.

BACKGROUND: Superior gluteal artery perforator flaps are surgical options in breast and pressure sore reconstructions. Based on the recipient site, primary thinning of these flaps may be necessary for final optimal contour. As the thinning of a superior gluteal artery perforator flap should be based on the knowledge of perforator vascular territories to prevent vascular compromise, the authors performed an anatomical study to determine the number, location, and diameter of the perforators present in the superior gluteal artery perforator flap. Accompanying veins and acceptable locations for surgical incisions were also determined. METHODS: Fourteen superior gluteal artery perforator flaps were harvested from seven cadavers. Perforator flaps were thinned to 8 to 15 mm, except for a 2.5-cm radius around the dissected perforator. Vascular territory areas were quantified before and after thinning by photographic and radiographic methods, and respective vascular territory maps were constructed. Surgical incision "danger zones" of vertical and horizontal axes were determined at specific depths (relative to the skin surface) for each flap. Danger zone measurements were determined with an automatic three-dimensional vascular tree construction using computed tomographic images and several modeling algorithms. RESULTS: Mean perforator artery diameter and number at the fascia level were 0.91 +/- 0.07 mm and 2.86 +/- 0.77 (mean +/- SD), respectively. Perforator pedicles were located midway between the posterior superior iliac spine and the greater trochanter. After thinning, skin surface and whole flap vascular territories were reduced 80.9 percent (photographic) and 76.9 percent (radiographic), respectively, compared with unthinned vascular territory areas. From the skin at 4-, 6-, and 8-mm thicknesses, elliptical danger zones (two vertical segments and two horizontal segments) had overall vertical segment axis length ranges from the pedicles of 59 to 66 mm, 51 to 57 mm, and 49 to 51 mm, respectively. Horizontal axis segment length ranges were 61 to 76 mm, 61 to 66 mm, and 60 to 57 mm for 4-, 6-, and 8-mm skin thicknesses, respectively. CONCLUSIONS: The superior gluteal artery perforator flap provides an excellent blood supply to adipose tissue but may be compromised when aggressively thinned. Surgeons may design and harvest partially thinned superior gluteal artery perforator flaps based on the anatomical vascular territory maps provided by this study.

Angiography↗
PubMed2006

Mastopexy preferences: a survey of board-certified plastic surgeons.

BACKGROUND: The purpose of this survey was to assess the current trends in mastopexy techniques and to compare satisfaction rates and complications associated with different techniques. METHODS: In September of 2002, a mastopexy survey was sent to 1500 members of the American Society for Aesthetic Plastic Surgery; 487 complete responses were received, for a response rate of 32.5 percent. Questions elicited categorical answers, and the data were evaluated using the chi-square test and the comparison of two proportions. RESULTS: The inverted-T incision technique is the most popular. Satisfaction was reported to be highest with the short scar periareolar inferior pedicle reduction (or SPAIR) and Hall-Findlay techniques. Physician satisfaction was lowest with the periareolar technique. The three most common complications for all techniques were suture spitting, excess scarring, and bottoming out. The periareolar group had a greater frequency of revision (p = 0.002). The inverted-T group had a greater frequency of bottoming out (p = 0.043). The short scar group had a greater frequency of asymmetry (p = 0.008). CONCLUSIONS: The traditional inverted-T technique is the most popular, but the newer short scar techniques have become more popular in the last 5 years. The inverted-T incision continues to be associated with bottoming out and excess scarring. The periareolar technique has the greatest need for revision and the lowest physician satisfaction, despite its application to a greater volume of mastopexies per year.

Adult↗
PubMed2005

Analysis of facial skin thickness: defining the relative thickness index.

BACKGROUND: The determination of human skin thickness has been achieved through various methods, both in vivo and in vitro. Ultrasound and histometric analyses have been the most commonly used. However, absolute values of epidermal and dermal thicknesses have demonstrated variability among the different modalities, leaving questions regarding the ability to standardize or compare results of different studies. METHODS: A cadaver study was designed to examine skin thicknesses in multiple anatomical sites from the same subject. Using three fresh adult cadavers, skin biopsy specimens were obtained at 15 facial sites that were identified as clinically relevant locations: upper lip vermilion, lower lip vermilion, philtral column, chin, upper eyelid, lower eyelid, brow/forehead, submental crease, right cheek, left cheek, right neck, left neck, malar eminence, nasal dorsum, and nasal tip. Histometric measurements were obtained at each location. RESULTS: In all subjects, the upper eyelid had the thinnest skin and was used as the denominator to calculate relative ratios of skin thicknesses with respect to other sites of the face. Using the upper eyelid average skin thickness, the nasal tip skin thickness was 3.30 times thicker and the brow/forehead was 2.8 times thicker. CONCLUSIONS: The authors propose a standardized and clinically useful method of skin thickness analysis by defining the relative thickness index. By examining relative values of skin thickness, using each subject as his or her own control, the authors demonstrated consistent ratios of dermal and epidermal thickness from one facial site to another.

Aged↗
PubMed2005

Evaluation of flashlamp-pumped pulsed-dye laser (585 nm) in nonsurgical delay of dorsal rat cutaneous flaps.

BACKGROUND: This study evaluated the efficiency of a flashlamp-pumped pulsed-dye laser operating at 585 nm in the delay of a caudally based, 10 x 3-cm dorsal rat skin flap. Two different laser treatment patterns (only longitudinal borders and the entire surface of the proposed flap) for two different fluences (6 J/cm and 8 J/cm) were compared with an acute untreated control flap as well as two surgical delay methods (incision of longitudinal borders and incision of longitudinal borders plus flap undermining). METHODS: Twelve male Sprague-Dawley rats were used in each of seven groups. Two additional rats were used for histologic evaluation and two rats were used for in vivo real-time video monitoring studies. Two weeks after delay procedures, the flaps were raised and sutured on the primarily closed flap donor area. After 5 days, the length of flap survival was measured. The effects of the laser on the cutaneous vasculature and perfusion were assessed by intravenous fluorescein injection, histologic analysis, microangiography, and in vivo real-time video monitoring. RESULTS: No statistically significant improvement in flap survival was observed in any of the laser treatment groups. CONCLUSIONS: The overall findings indicate that the flashlamp-pumped pulsed-dye laser operating at 585 nm did not penetrate deep into skin and coagulate the subdermal plexus with tested laser settings and did not induce the delay phenomenon.

Animals↗
PubMed2005

Defining vascular supply and territory of thinned perforator flaps: part I. Anterolateral thigh perforator flap.

BACKGROUND: The anterolateral thigh perforator flap is increasingly being used for trauma and reconstructive surgical cases. With the thinned flap design, greater survivability and a decrease in donor-site morbidity are observed. To increase our knowledge of the vascular territories in these flaps, an anatomic study was performed to determine pedicle number, location, and diameter; accompanying veins; vascular territory; and where surgical incisions can be made safely during thinning, as opposed to the "danger zone." METHODS: Thirteen anterolateral thigh perforator flaps were harvested from seven adult cadavers. The largest perforator arteries were cannulated, and flaps were thinned to a thickness of 6 to 8 mm, with a 2.5-cm radius from the perforator retained. Vascular territories were quantified before and after thinning by nonradiographic and radiographic methods. A series of dyes were injected: red dye for skin (photography) followed by Omnipaque for the whole flap (radiography) before thinning, and blue dye for skin (photography) and lead oxide for the whole flap (radiography) after thinning. Pedicle locations were determined by ratios of anatomical landmarks. Danger zone measurements were derived at specific thicknesses using lateral radiographs of each flap. RESULTS: In anterolateral thigh perforator flaps, the mean perforator artery diameter at the fascia level was 1.00 +/- 0.08 mm (range, 0.84 to 1.11 mm) and the mean number of perforator arteries was 1.69 +/- 1.03 (+/-SD). Perforator pedicles were located near the midpoint of the line between the anterior superior iliac spine and the lateral aspect of the patella in the vertical axis. The mean vascular territories were 256 +/- 52.5 cm2 (photography) and 351 +/- 72.8 cm2 (radiography) in unthinned flaps and 211 +/- 65.7 cm2 (photography) and 289 +/- 106.6 cm2 (radiography) in thinned flaps. Differences in overall vascular territories after thinning were 83.3 percent (photography) and 81.8 percent (radiography) compared with unthinned flaps. Four respective vascular territory maps were drawn showing surgical territories using percentile confidence intervals (98th and 90th) and averages. From the skin at thicknesses of 4, 6, and 8 mm, the 98th percentile danger zones were 33 to 37 mm (proximal to distal), 30 to 35 mm, and 27 to 31 mm from the pedicle in the vertical axis, respectively; in the horizontal axis, they were 30 to 34 mm (medial to lateral), 28 to 31 mm, and 25 to 29 mm. CONCLUSIONS: These data define anterolateral thigh perforator flap pedicle location, number, and diameter before harvesting, surgical danger zones during thinning, and vascular territories after thinning. The authors' guidelines provide surgeons with anatomical vascular territory maps to design and harvest specific flaps for optimal results.

Aged↗
PubMed2005

Nonsurgical delay of dorsal rat cutaneous flap using a long-pulsed 1064-nm Nd:YAG laser with a contact cooling device.

BACKGROUND: This study evaluated the efficiency of a long-pulsed neodymium:yttrium-aluminum-garnet laser, operating at 1064 nm and equipped with a contact cooling device, in the delay of a caudally based dorsal rat skin flap (10 x 3 cm). This laser has deeper tissue penetration and has not been used for this purpose before. METHODS: Twelve male Sprague-Dawley rats were used in each of six groups. The delay effects of three different laser treatment patterns (only longitudinal borders, cephalic and longitudinal borders, and entire surface of the 10 x 3-cm flap) were compared with an acute untreated control flap as well as two surgical delay methods (incision of longitudinal borders and incision of longitudinal borders plus flap undermining). The laser effects on the cutaneous vasculature and perfusion were assessed by intravenous fluorescein injection, histologic study, microangiography, and in vivo real-time video monitoring. RESULTS: Selective thermocoagulation of subdermal vessels was achieved using a 6-mm spot, 140-J/cm fluence, and 40-msec pulse width. In the cephalic and longitudinal borders laser-treated group, a delay effect was achieved. The maximum delay effect was achieved by the surgical delay group that used the method of incision of the longitudinal borders plus flap undermining. Laser treatment of only the longitudinal borders did not improve flap survival, whereas treatment of the entire flap surface significantly reduced flap survival. CONCLUSION: Nonsurgical delay of a dorsal rat cutaneous flap is possible by selective occlusion of the subdermal plexus at the longitudinal and cephalic borders of the planned flap using a long-pulsed 1064-nm neodymium:yttrium-aluminum-garnet laser equipped with a contact cooling device.

Animals↗
PubMed2004

Pharmacokinetics and safety of epinephrine use in liposuction.

Patients are routinely exposed to high-dose epinephrine infiltration during large-volume liposuction. Because of the serious cardiovascular side-effect profile of catecholamine overdose, the authors examined the safety of larger-volume liposuction by assessing epinephrine pharmacokinetics. Five female volunteers with American Society of Anesthesiologists physical status of I or II, aged 29 to 40 years and weighing 75.9 to 95 kg, underwent liposuction. The wetting solution contained 7.3 mg (SEM, 0.7 mg) of epinephrine, corresponding to 0.09 mg/kg (0.04 mg/kg). Total plasma epinephrine and norepinephrine concentrations were assessed by high-performance liquid chromatography. Approximate exogenous epinephrine absorption was calculated after correction for estimated endogenous epinephrine production. Pharmacokinetic assessments were performed using standard equations. The total plasma epinephrine peak occurred at the final intraoperative reading (5 hours after induction) and was 323 pg/ml (24.8 pg/ml), three to four times maximum baseline resting levels. The norepinephrine level was slightly elevated throughout the study period, with a reversal of the normal epinephrine/norepinephrine ratio (<0.5:1) demonstrated intraoperatively (>5:1). Estimated time to peak exogenous epinephrine level ranged from 1 to 4 hours from the start of infiltration. Area under the plasma concentration versus time curve was approximately 2089 to 2610 pg x hour/ml. Peak exogenous epinephrine concentration was estimated to be 286 to 335 pg/ml. Clearance was 764,508 ml/hour and volume of distribution was 0.4 liter/kg (0.006 liter/kg). Total absorbed epinephrine was estimated, 1.8 mg to 2.2 mg, equivalent to 25 to 32 percent of the infiltrated dose. The reversal of the normal epinephrine/norepinephrine ratio and the fact that norepinephrine levels were within normal range implied that the majority of plasma epinephrine measured was exogenously infiltrated and not endogenously synthesized. On the basis of these observations, pharmacokinetic analyses were performed. Although unequivocal toxic epinephrine levels were not demonstrated, epinephrine peaks were three to four times the maximum observed in normal resting patients. Peak levels were comparable to those observed during major physiologic stresses, such as exercising to exhaustion, open abdominal surgery, or cross-clamping the aorta during surgical repair. Furthermore, epinephrine has been associated with myocardial infarction, arrhythmias, and fatal asystole in susceptible patients at these levels. Patients should be carefully screened for clinical evidence of hemodynamic and cardiac pathology before larger-volume liposuction is undertaken, as it may result in unnecessary high risk for patients who have preexisting cardiovascular disorders. Healthy American Society of Anesthesiologists physical status I or II patients should have sufficient cardiac reserve to tolerate these catecholamine levels.

Adult↗
PubMed2004

Electrolyte and plasma enzyme analyses during large-volume liposuction.

Substantial fluid shifts occur during liposuction as wetting solution is infiltrated subcutaneously and fat is evacuated, causing potential electrolyte imbalances. In the porcine model for large-volume liposuction, plasma aspartate aminotransferase and alanine transaminase levels were elevated following liposuction. These results raised concerns for possible mechanical injury and/or lidocaine-induced hepatocellular toxicity in a clinical setting. The first objective of this human model study was to explore the effect of the liposuction procedure on electrolyte balance. The second objective was to determine whether elevated plasma aminotransferase levels were observed subsequent to large-volume liposuction. Five female volunteers underwent three-stage, ultrasound-assisted liposuction. Blood samples were collected perioperatively. Plasma levels of sodium, potassium, venous carbon dioxide, blood urea nitrogen, chloride, and creatinine were determined. Liver function analyte levels were measured, including albumin, total protein, aspartate aminotransferase, and alanine transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase, and total bilirubin. To further define intracellular enzyme release, creatine kinase levels were measured. Mild hyponatremia was evident postoperatively (134 to 136 mmol/liter) in four patients. Hypokalemia was evident intraoperatively in all subjects (mean +/- SEM; 3.3 +/- 0.16 mmol/liter; range, 3.0 to 3.4 mmol/liter). Hypoalbuminemia and hypoproteinemia were observed throughout the study (baseline: 2.9 +/- 0.2 g/dl; range, 2.6 to 3.5 g/dl), decreasing to 10 to 40 percent 24 hours postoperatively (2.0 +/- 0.2 g/dl; range, 1.7 to 2.1 g/dl). Aspartate aminotransferase, alanine transaminase, and creatine kinase levels were significantly elevated after the procedure (190 +/- 47.1 U/liter, 50 +/- 7.7 U/liter, and 11,219 +/- 2556.7 U/liter, respectively) (p < 0.01). Release of antidiuretic hormone and even mildly hypotonic intravenous fluid infiltration have long been known to cause hyponatremia postoperatively. Intraoperative hypokalemia is associated with hypocarbia and respiratory alkalosis and the elevated epinephrine levels observed in the concurrent study. Factors having the greatest initial impact on diminished serum albumin and protein levels postoperatively are redistribution and hemodilution. Subsequent diminished viscosity may significantly affect postoperative hemodynamics. Elevated aspartate aminotransferase, alanine transaminase, and creatine kinase levels are associated with skeletal muscle injury, adipocyte lysis, and/or hepatic damage. Therefore, tissue injury is associated with large-volume liposuction as observed in several cellularly released enzymes. Future clinical studies are required to determine the degree of injury and specific tissues that are damaged or sensitive to mechanical trauma and/or drugs used in large-volume liposuction.

Alanine Transaminase↗
PubMed2004

Hemodynamics, electrolytes, and organ histology of larger-volume liposuction in a porcine model.

Liposuction is a procedure that allows the surgical removal of excess adipose tissue in healthy individuals. Lipoplasty is commonly performed with few clinical side effects. However, with increased lipoaspirate volumes, complications have been reported. In addition, the abnormal appearance of fat cells in other tissues subsequent to lipoplasty has been reported in a small number of cases. The authors examined whether larger-volume lipoplasty, in the porcine model, resulted in disturbances in cardiac or pulmonary output levels, electrolytes, and liver chemistry analyses or alterations in organ histology. Nine adult porcine specimens were subjected to either lipoplasty (n = 6) with the superwet technique or no lipoplasty (n = 3). Using a Swan-Ganz catheter, cardiac output and pulmonary artery pressure measurements were obtained from initial placement before lipoplasty until 48 hours postoperatively. Blood analyte measurements were obtained. Upon euthanization, liver, kidney, and lung specimens were collected and tissue sections were prepared. No significant differences or trends were observed in cardiac parameters or blood analytes between control and experimental groups. Significant elevations in serum aspartate aminotransferase and alanine aminotransferase enzyme levels (p < 0.03) were observed in animals postoperatively (10 to 48 hours) subjected to lipoplasty compared with controls. Upon gross examination, the lung tissues of animals subjected to lipoplasty unexpectedly demonstrated patchy petechial hemorrhages on the pleural surface. Tissue sections revealed marked hemorrhagic congestion and evidence of pulmonary edema. Fat emboli were also identified within the pulmonary and renal systems.

Alanine Transaminase↗
PubMed2004

A prospective controlled assessment of microdermabrasion for damaged skin and fine rhytides.

Aged skin is characterized by rhytides but also by epidermal and dermal atrophy, rough skin texture, irregular pigmentation, telangiectasias, and laxity. Microdermabrasion is an office-based mechanical resurfacing technique alternative to traditional dermabrasion. It has been used in Europe since 1992 with great acceptance. The purpose of this study was to evaluate and quantify the degree of visible improvement in photodamaged skin and fine rhytides following a series of microdermabrasion treatments. A single operator treated 20 patients with varying degrees of photodamage and rhytides with a series of eight microdermabrasion treatments at 1-week intervals; 17 subjects completed the entire study protocol. Standardized photographic documentation was performed before and after each treatment, and a survey questionnaire was completed by each subject. Punch biopsy specimens (3 mm) were collected on treated and matched nontreated control sites and evaluated for histological characteristics. Preprocedure and postprocedure photographs were rated on a 5-point scale by independent blinded observers. A total of 30 blinded observers (16 plastic surgeons and 14 laypersons) rated all photographs. The results showed that all observers rated a significant improvement of hyperchromic discoloration (p = 0.004), while only nonmedical observers observed improvement in fine rhytides. All patients were very satisfied with the results. Common side effects were mild to moderate discomfort occurring on bony areas during the treatment and an itching and tingling sensation for 2 days after treatment. No infections or scars were observed postoperatively. The average epidermal thickness in the untreated samples was 103 +/- 23 microM (mean +/- SD) before treatment compared with 148 +/- 41 microM after treatment (p < 0.001). Histologic analysis of the matched punch biopsy specimens showed an increase in organized collagen in treated versus nontreated sites. Treatment of aged skin using a series of microdermabrasion treatments is an effective, noninvasive method of skin rejuvenation with minimal risk and patient downtime. It is safe and improves skin quality by minimizing certain hyperchromic pigmentations.

Adult↗
PubMed2004

A useful algorithm for determining fluence and pulse width for vascular targets using 1,064 nm Nd:YAG laser in an animal model.

BACKGROUND AND OBJECTIVES: Many current parameters to ablate vascular beds using 1,064 nm lasers are based on high-energy settings and often fail to consider vessel diameter and/or pulse width. This study attempts to define the minimal effective dosage (MED) of energy and pulse width for specific vessel diameters in an animal model. STUDY DESIGN/MATERIALS AND METHODS: 1,064 nm Nd: YAG was used in 15 Sprague-Dawley rats. Bilateral extended dorsolateral skin flaps were elevated and vessel diameters from 0.1 to 1 mm were identified. Pulse widths (PW) in a range of 15-60 milliseconds and fluences between 70-110 J/cm2 with contact cooling at 5 degrees C (Celsius) were utilized. Results were determined clinically and histologically. RESULTS: Ideal pulse width and MED for each vessel diameter were determined using a 6 mm spot size. Histology showed early hemostasis and subsequent thrombosis, which are consistent with clinical findings. CONCLUSIONS: This model allows in vivo monitoring of vessel ablation. Optimal pulse width and MED levels versus vessel diameter determined in this animal model provide a useful algorithm that may allow for more effective treatment of vascular targets utilizing the 1,064 nm Nd:YAG laser.

Algorithms↗