Skin resurfacing with erbium:YAG lasers. Plastic Surgery Educational Foundation DATA Committee.
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Dermatologic Surgical Procedures↗
Biomedical subjects
L S Bass
Publications and source records attributed to L S Bass.
Carbon dioxide and ER:YAG laser resurfacing. Results.
Laser resurfacing is exciting "futuristic" surgery. The CO2 laser resurfaces using different parameters from the Er:YAG laser. When the surgeon understands these parameters, each laser can be used as a powerful tool for specific clinical applications. The Er:YAG laser was initially thought to be for the patient who has minimal skin laxity, but who desires skin resurfacing and needs a speedy return to social life. The CO2 laser has typically been thought to work best for skin laxity as well as rhytids, at the price of a longer recovery period. As the hardware and techniques continue to evolve, the differences between the clinical scope addressed by each laser diminishes. Both lasers deserve a place in the plastic surgeon's armamentarium. This new combination CO2/Er:YAG technique is intriguing and deserves further in-depth investigation. Laser resurfacing is not a cureall, but, when applied appropriately, it is an excellent tool that the plastic surgeon can use for skin rejuvenation.
Dermatologic Surgical Procedures↗
Effect of optical temperature feedback control on patency in laser-soldered microvascular anastomosis.
Feedback control has been postulated to improve the efficacy of laser welding in microsurgery, but alteration of outcome has not been clearly shown. The authors evaluated the ability of an optical closed loop temperature feedback control to improve patency, aneurysm rate, and to histologically limit thermal damage. Rat femoral artery anastomoses were performed under operating microscope magnification. One hundred and twenty-four anastomoses were performed in five groups using 1) free-hand (FH) 1.9-microm laser soldering without feedback; 2) temperature controlled (TC) 1.9-microm laser soldering with optical feedback; 3) FH 808 nm laser; 4) TC 808 nm laser soldering; and 5) 10-0 nylon suture control. In Groups 2 and 4, an optical feedback system controlling laser exposure to produce a preset temperature was used. Anastomotic time was significantly less for all laser groups (p < 0.05). Late patency for all 1.9-microm laser anastomoses was almost 0. Temperature controlled 808-nm anastomoses showed no significant difference from sutures in terms of patency (88 percent vs. 96 percent), bursting pressure, and aneurysm rate, while freehand 808-nm anastomoses had a significantly lower patency (71 percent) and more tissue damage (ANOVA, p < 0.05). The authors conclude that temperature control improves outcome in microvascular anastomosis by reducing transmural thermal injury caused by variations in surgeon technique.
Anastomosis, Surgical↗
Erbium:YAG laser skin resurfacing: preliminary clinical evaluation.
Each of the increasing number of resurfacing lasers uses a unique strategy to produce tissue ablation. Erbium:YAG (Er:YAG) lasers have been used in other applications for precise tissue removal with little thermal effect. Recovery time, duration of erythema, and clinical improvement were evaluated using an Er:YAG resurfacing laser (2.94-microm wavelength, 350-microsec pulse, 2 J, 3-5-mm spot). Twenty-five patients were treated with two passes to the full face and 3 to 5 passes to the most affected aesthetic unit. At each follow-up visit, percent epithelialization, erythema, and swelling were graded, and the presence or absence of complications was noted. Clinical improvement was evaluated at 6 months by optical profilometry on a subset of patients. Er:YAG resurfacing produced a transient whitening of dermis followed by a resumption of pink appearance. The surgical end point was judged by elimination of visible rhytids or presence of punctate bleeding. Bleeding from the dermal surface was encountered less than customarily in dermabrasion, but more than seen with carbon dioxide laser resurfacing. A moderate amount of tissue shrinkage was observable during the treatment. Mean period to full epithelialization was 6.9+/-0.97 days (range, 5-9 days). The mean duration of erythema (4.24+/-1.5 weeks) was relatively short compared with carbon dioxide resurfacing. Clinical improvement was 44+/-30% in the lateral canthal area and 55+/-22% in the upper lip area. There were no infections or hypertrophic scars. Hyperpigmentation and hypopigmentation was seen in 24% and 12% of patients respectively. Er:YAG resurfacing is a reliable means of obtaining rhytid improvement with less recovery time and duration of erythema compared with carbon dioxide resurfacing. The technique is significantly different from carbon dioxide resurfacing in selection of end point, number of passes, and energy settings.
Erythema↗
A balloon-assisted facialplasty technique.
An ongoing goal of aesthetic surgery is a reduction in complications and an improvement in reproducibility and speed. Balloon dissector devices have been used in other areas of surgery to achieve these goals. This report presents early clinical experience using a balloon dissector to elevate the skin flap in facialplasty. The first step in the technique is the creation of a tunnel from a small preauricular incision toward the oral commissure using scissors dissection. The balloon device is inserted into this tunnel and inflated. Unrolling the device elevates the skin flap in the cheek and neck area. Retroauricular dissection and final adjustment of flap size and shape is completed sharply. Subsequent superficial musculoaponeurotic system flap development, skin redraping, and closure is performed in a conventional fashion after customary facialplasty incisions are made. Comparison of complications, postoperative drainage, and time required for dissection and for hemostasis was made between a balloon-dissected side and a conventionally dissected side in 10 patients undergoing facialplasty. Ten additional patients were treated with balloon dissection bilaterally. Patients ranged in age from 45 to 73 years. Mean balloon dissection time was 1.4 minutes (range, 0.75-4 minutes). This produced an even flap thickness in the correct plane with few if any bleeding points. Mean total dissection time on the balloon side was significantly shorter-13.6 minutes-compared with 27.8 minutes (p < 0.003) on the conventional side. Mean difference in time to hemostasis between conventional and balloon sides was 3.8 minutes (p < 0.001). Mean total postoperative drainage (all drains removed at 24 hours) was 13.8 cc on the balloon side and 18.8 cc on the conventional side (not significant, p=0.08). Less ecchymosis and swelling was observed on the balloon side compared with the scissors-dissected side. There were no skin losses, hematomas, infections, or nerve injuries on either side. Appearance of skin redraping was comparable on each side in all patients. Balloon dissection represents a promising alternative means of creating rapid, reproducible skin flap elevation in facialplasty, and is associated with a minimum of bleeding, ecchymosis, and swelling.
Aged↗
Balloon assisted endoscopic harvest of the latissimus dorsi muscle.
In this study, we present our experience with balloon assisted endoscopic harvest of the latissimus dorsi muscle for extremity reconstruction. The balloon performs most of the dissection under the muscle and creates the optical work space used in the endoscopic dissection. Over the course of this series the operative time has been reduced and averaged 2 hours and 44 minutes. The reconstructive goals were met in all cases. The average axillary incision length was 5.6 cm, and there were an average of 1.3 one-centimeter or smaller counter incisions.
Endoscopes↗
Thrombocytosis after major lower extremity trauma: mechanism and possible role in free flap failure.
Microvascular thrombosis and free flap failure are complications of free tissue transfer for coverage of lower extremity soft-tissue and bony defects despite appropriate vessel selection and adherence to meticulous technique. Increased rates of flap failure have been associated with reconstruction performed between 3 days and 6 weeks after injury, as well as in patients with thrombocytosis. We have found that serum platelet levels rise significantly after lower extremity injury. It is our theory that a circulating mediator or cytokine is released in response to injury, inducing the thrombocytosis. Twenty-one patients with Gustilo grade IIIb and IIIc injuries were studied prospectively. Serum was collected throughout the postinjury period. Platelet count, leukocyte count, hemoglobin concentration, and hematocrit were determined. Samples were also subjected to a platelet aggregation study as well as enzyme-linked immunosorbent assay for interleukin-3, interleukin-6, interleukin-11, and granulocyte macrophage-colony-stimulating factor. Megakaryocyte growth and development factor enzyme-linked immunosorbent assay and a myleoproliferative leukemia virus-transfected cell line assay for thrombopoietin were performed. Bone marrow was studied with flow cytometric analysis. Mean initial platelet count was 196,000 per cubic millimeter. There was an initial 26% decline to 140,000 per cubic millimeter, followed by an increase to 361% of baseline on day 16. No significant variations in serum leukocyte count or hemoglobin concentration were seen. Spontaneous and induced platelet aggregation responses were normal. Interleukin-6 was detected at elevated levels. However, interleukin-3, interleukin-11, granulocyte macrophage-colony-stimulating factor, and thrombopoietin were not measurable. Marked megakaryocytosis was seen on bone marrow analysis. Interleukin-6 may, therefore, play a role in the mechanism of thrombocytosis. We suggest that because patients with complex bony injuries of the leg experience platelet elevations that peak approximately 2 weeks after injury, microvascular free flap reconstructions should be considered high risk during this time period.
Adult↗
Laser tissue welding: a comprehensive review of current and future clinical applications.
Laser techniques for joining tissue, in combination with other surgical technologies, will be a hallmark of surgery in the next century. At present, there are many clinical applications of tissue welding and soldering which are beginning to achieve wide spread acceptance. These exciting clinical developments are the result of many advances which have been made in the past few years in our understanding of the mechanism of laser tissue welding. Also contributing to this progress are many important technical refinements such as tissue solders and feedback control of the laser device. In this article, we describe in depth the history and development of laser tissue welding including key theoretical concepts as well as crucial experiments which have added to our insight into this phenomenon. We also review the evolving concepts of its clinical application and indicate clinical applications which are likely to become more important in the future.
Equipment Design↗
Endoscopic harvest of the rectus abdominis free flap: balloon dissection in the fascial plane.
Free-flap donor sites are a frequent source of morbidity, including scar deformity and reduced mobility, as well as a significant contributor to recovery time after surgery. We present our technique for endoscopic harvest of the rectus abdominis muscle. A groin crease incision is made, which allows identification of the vascular pedicle and access to the inferior portion of the muscle. A balloon dissection device is inserted along the posterior rectus sheath and inflated. The inferior incision is closed over an endoscopic port after medial and lateral ports are inserted under direct vision at the level of the umbilicus. The cavity is insufflated with carbon dioxide, allowing visualization using a 10-mm, 30-degree endoscope. The remaining dissection is performed sharply, and the muscle is harvested via the groin incision. This technique has proved feasible during study in fresh human cadavers. Insufflation greatly reduces work load with retractors. The balloon device speeds dissection with a minimum of trauma. Because all dissection is performed from within the rectus sheath, the peritoneal cavity is not violated. Endoscopic rectus abdominis harvest using the fascial plane is safe and efficient and carries the potential to reduce donor-site morbidity.
Fasciotomy↗
Understanding laser-tissue interactions helps predict clinical effects.
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Arteriovenous Malformations↗
Influence of steroids on postoperative swelling after facialplasty: a prospective, randomized study.
Steroids are widely used in facial aesthetic surgery to reduce postoperative edema. We performed a randomized, double-blind study to try to document the effectiveness of this practice. Fifty consecutive facialplasty patients of one surgeon were randomized to steroid and no steroid groups. Steroid group patients received betamethasone 6 mg IM preoperatively. Postoperative scoring of swelling was performed at approximately days 5 and 9 by a single observer. There were no significant differences between the two groups at either postoperative interval or in the rate of improvement. Subgroups of patients who underwent additional procedures also showed no significant differences. We were not able to demonstrate any statistically significant difference in swelling after facialplasty with this steroid regimen.
Adult↗
Canine choledochotomy closure with diode laser-activated fibrinogen solder.
BACKGROUND: An alternative to mechanical stapling or hand suturing is needed to permit laparoscopic common bile duct exploration. We evaluated the strength and healing characteristics of canine choledochotomies sealed with a fibrinogen solder and a diode laser. METHODS: After creation of a 0.5 cm longitudinal choledochotomy, the edges were coapted with forceps, and a fibrinogen solder mixed with indocyanine green dye was applied. The solder was sealed in place with an 810 nm diode laser (125 W/cm2). RESULTS: Immediate mean leakage pressure was 264 +/- 7 mm Hg compared with 83 +/- 66 mm Hg in suture controls. This increased to 364 +/- 115 mm Hg at 2 days and was more than 510 mm Hg at 7 days. On histologic examination rapid reabsorption of the solder with no signs of inflammation or stenosis was seen. No episodes of dehiscence or peritonitis occurred. CONCLUSIONS: Laser soldering provides a watertight choledochotomy closure with adequate immediate strength allowing a reliable, technically feasible common bile duct exploration via a laparoscopic approach.
Animals↗
Laser-assisted fibrinogen bonding of umbilical vein grafts.
Despite success with autologous tissue welding, laser welding of synthetic vascular prostheses has not been possible. The graft material appears inert and fails to allow the collagen breakdown and electrostatic bonding that results in tissue welding. To develop a laser welding system for graft material, we repaired glutaraldehyde-tanned human umbilical cord vein graft incisions using laser-assisted fibrinogen bonding (LAFB) technology. Modified umbilical vein graft was incised transversely (1.2 cm). Incisions were repaired using sutures, laser energy alone, or LAFB. For LAFB, indocyanine green dye was mixed with human fibrinogen and the compound applied with forceps onto the weld site prior to exposure to 808 nm diode laser energy (power density 4.8 W/cm 2). Bursting pressures for sutured repairs (126.6 +/- 23.4 mm Hg) were similar to LAFB anastomoses (111.6 +/- 55.0 mm Hg). No evidence of collateral thermal injury to the graft material was noted. In vivo evaluation of umbilical graft bonding with canine arteries demonstrates that LAFB can reliably reinforce sutured anastomoses. The described system for bonding graft material with laser exposed fibrinogen may allow creation or reinforcement of vascular anastomoses in procedures where use of autologous tissue is not feasible.
Anastomosis, Surgical↗
Changes in type I collagen following laser welding.
Selection of ideal laser parameters for tissue welding is inhibited by poor understanding of the mechanism. We investigated structural changes in collagen molecules extracted from rat tail tendon (> 90% type I collagen) after tissue welding using an 808 nm diode laser and indocyanine green dye applied to the weld site. Mobility patterns on SDS-PAGE were identical in the lasered and untreated tendon extracts with urea or acetic acid. Pepsin incubation after acetic acid extraction revealed a reduction of collagen alpha and beta bands in lasered compared with untreated specimens. Circular dichroism studies of rat tail tendon showed absence of helical structure in collagen from lasered tendon. No evidence for covalent bonding was present in laser-treated tissues. Collagen molecules are denatured by the laser wavelength and parameters used in this study. No significant amount of helical structure is regenerated on cooling. We conclude that non-covalent interactions between denatured collagen molecules may be responsible for the creation of tissue welding.
Animals↗
New technologies and future applications of surgical lasers. The right tool for the right job.
The real future of surgical lasers, and indeed of surgery itself, will depend on the integration of the surgeon into a system incorporating real-time tissue sensors, computer-directed robotic manipulation, and laser-tissue interactions that are customized to the clinical task. The human surgeon will operate as the central judgmental element in this mechanized and semiautomated laser surgical system. Only then will we really be able to make use of the subtle and varied laser-tissue effects now being discovered.
Animals↗
Alternative wavelengths for sutureless laser microvascular anastomosis: a preliminary study on acute samples.
Attempts to improve the speed and patency of microvascular anastomosis with laser-assisted techniques have provided a modest reduction in operative time and comparable success rates. Using sutureless microvascular anastomoses, 30 end-to-end anastomoses were created in the rat carotid artery using the gallium-aluminum-arsenide diode laser (808 nm). Indocyanine green and fibrinogen were applied to enhance tissue absorption of the laser energy and strengthen the bond created. These were compared with previously reported welds using the THC:YAG laser (2150 nm). Mean welding times were 140 and 288 s, and mean bursting pressures immediately after welding were 515 and 400 mmHg for the diode and THC:YAG laser groups, respectively. Histologically, both lateral and vertical spread of thermal damage was limited. Since both lasers create welds of adequate initial strength without stay sutures and are faster and easier to use than existing systems, evaluation of long-term patency would be worthwhile.
Anastomosis, Surgical↗
Alternative lasers for endoscopic surgery: comparison of pulsed thulium-holmium-chromium:YAG with continuous-wave neodymium:YAG laser for ablation of colonic mucosa.
Precise and controllable tissue vaporization is essential for minimizing risk in removal of sessile polyps from the lumen of thin walled gastrointestinal organs such as the colon. We compared the ablative efficiency on canine colonic mucosa of the THC:YAG laser with the clinically employed cw Nd:YAG laser. Fresh canine colon was treated with a progressive dose schedule using each laser at several energy/power densities. Ablation depth was measured on fresh tissue and thermal (non-ablation or coagulative) damage examined histologically. The THC:YAG ablation rates were 13.7 +/- 0.8 and 10.2 +/- 0.4 microns/J at 55 and 85 J/cm2, respectively. The Nd:YAG laser generated 3.7 +/- 0.3, 2.8 +/- 0.1, and 3.6 +/- 0.2 microns/J at 4,460, 5,095, and 5,730 W/cm2, respectively. There was a significant (P less than 0.001) difference among the THC:YAG ablation rates and between the THC:YAG and Nd:YAG ablation rates (ANOVA). The THC:YAG laser craters had significantly less collateral thermal damage than Nd:YAG. The pulsed THC:YAG laser should have an important clinical role since its use could reduce the risk of perforation in endoscopic laser procedures such as the removal of sessile polyps.
Aluminum Silicates↗
Motivation strategies: a new twist.
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Employee Incentive Plans↗