Biomedical subjects

S J Mathes

Publications and source records attributed to S J Mathes.

At least 37 records · Page 2Linked to original sources

PubMed1994

Changing trends in postmastectomy breast reconstruction: a 13-year experience.

Over the past two decades, significant advances have been made in the treatment of breast cancer and reconstruction following mastectomy. This analysis represents a 13-year review (1979-1991) of 455 postmastectomy reconstructions involving 381 patients (age range 25 to 76 years, mean 51 years). Follow-up was 6 months to 13 years (mean 5 years). Timing of the reconstruction, reconstructive techniques used, incidence of complications, and final results were determined. Reconstructions were divided into three chronologic study groups: group I, 1979-1983; group II, 1984-1987; and group III, 1988-1991. A significant increase in the use of autogenous reconstruction was identified: 13 percent in group I to 37 percent in group III (p < 0.0002). Complication rates were not significantly different among the three groups (p > 0.02). Significant decreases in the use of implants alone and the latissimus dorsi flap with implant were identified, while tissue expansion and TRAM flap use increased significantly (p < 0.002). Also, a significant increase in immediate reconstruction from 6 percent in group I to 28 percent in group III occurred (p < 0.0002). There was no significant difference in complication rates between immediate and delayed reconstruction in any study group. Operative time averaged 2 hours less for nonautogenous techniques; however, autogenous reconstruction required significantly fewer operative revisions. The identified trends toward immediate reconstruction and use of autogenous tissue have been accomplished without an increase in complications. Despite a decrease in overall implant use, the textured silicone saline-filled expander/implant remains the most frequently used device for breast reconstruction, providing a safe and predictable method to accomplish both immediate and delayed postmastectomy reconstruction.

Adult↗

PubMed1994

Efficacy of RS-61443 in reversing acute rejection in a rat model of hindlimb allotransplantation.

The requirement for effective, minimally toxic immunosuppression remains a major obstacle to performing human composite tissue allotransplantation. The skin component of composite tissue (e.g., limb) allografts is especially antigenic, necessitating toxic immunosuppressant doses to prevent or reverse acute rejection. In previous experiments, RS-61443, an experimental mycophenolic acid ester that inhibits lymphocyte proliferation with minimal toxicity, prevented acute limb allograft rejection in rats for more than 8 months when started on the day of transplantation. In this study, the ability of RS-61443 to reverse established acute rejection was tested in a rat model of hindlimb allotransplantation. Brown-Norway donors and Fischer 344 recipients provided a MHC mismatch for orthotopic midfemur limb transplants that were performed with microsurgical repair of femoral vessels and sciatic nerve. Three groups were studied: untreated allografts (n = 6); allografts receiving RS-61443 at 30 mg/kg/day, started on postoperative day 7 (n = 11); and allografts receiving RS-61443 at 30 mg/kg/day, started on postoperative day 9 (n = 9). Skin and soft tissues were biopsied periodically to assess rejection. Untreated allografts had complete acute rejection within 12-13 days. Animals in both the 7- and 9-day groups developed moderate to severe rejection clinically and histologically before initiation of immunosuppressive therapy. In both groups, RS-61443 was able to reverse rejection completely in all animals from which biopsies were obtained at the time of death at 9-16 weeks after transplantation (P < 0.007). RS-61443 was highly effective as a primary immunosuppressant for reversing established acute rejection in rat hindlimb allografts.

Animals↗

PubMed1994

Pharyngoesophageal reconstruction using the tubed free radial forearm flap.

Patients undergoing laryngopharyngectomy require the restoration of both deglutition and voice. We believe the tubed radial free flap offers the combined advantages of a rapid harvest with minimal morbidity, a long flap pedicle, extraordinary reliability, and the possibility of customization to fit virtually any size of defect. This flap does have a somewhat higher leakage rate; however, such leaks are relatively minor and nearly all will resolve with a brief period of conservative treatment. Postoperatively, this flap tolerates radiation therapy very well. Most importantly, it maximizes the functional rehabilitation of the patient by providing the best speech and swallowing results available. For these reasons we consider the tubed radial forearm free flap to be the flap of choice for circumferential pharyngoesophageal reconstruction.

Esophageal Neoplasms↗

PubMed1993

Color flow ultrasound for delineating microsurgical vessels: a clinical and experimental study.

There is a need in plastic and reconstructive surgery for a method of monitoring flaps and replants pre- and postoperatively. This study evaluates color flow Doppler done as a monitoring technique for microvascular vessels. The capability of color flow ultrasound to monitor venous and arterial insufficiency and occlusion was studied by means of an experimental system in the Yucatan miniature swine model. A circulatory circuit in line with a magnetic flow probe is created. Measurements are made on the isolated hind limb of the animal. Color flow ultrasound is demonstrated to be a technique that is sensitive to venous and arterial insufficiency at flow rates as low as 3.0 ml/min. Characteristic waveform patterns are shown to predict arterial and venous insufficiency before they actually progress to occlusion. A clinical series of 25 postoperative patients is presented, consisting of volunteer studies as well as pre- and postoperative examinations of free flaps and replantations. Color flow ultrasound is shown to visualize a spectrum of pre- and postoperative microvascular conduits encountered in plastic and reconstructive surgery.

Anastomosis, Surgical↗

PubMed1993

A long-term study of allogeneic rat hindlimb transplants immunosuppressed with RS-61443.

Although technically possible, limb allotransplantation has not been applied clinically. The skin component is especially antigenic, requiring high immunosuppressant doses with an unacceptable toxicity profile. RS-61443, an experimental mycophenolic acid ester that inhibits lymphocyte proliferation without major systemic toxicity, was tested as an immunosuppressant to prevent rejection of rat hindlimb allotransplants. Utilizing Brown-Norway donors and F344 recipients to provide a major mismatch at the MHC, midfemur orthotopic limb transfer was performed with microsurgical repair of femoral vessels and sciatic nerve. Four primary groups were studied: autografts (n = 4); untreated allografts (n = 6); allografts receiving CsA 10 mg/kg for 20 days, then twice per week (n = 6); and allografts receiving RS-61443 30 mg/kg/day (n = 6). Skin and soft tissues were biopsied to assess rejection. Autografts had indefinite limb survival, while untreated allografts had complete acute rejection within 10-12 days. Five of the six CsA rats developed delayed mild-moderate acute rejection within 6 months. In contrast, 5 of the 6 RS-61443 rats had no rejection after at least 32 weeks, while the sixth rat developed only slight rejection on skin biopsy. All animals regained full sensation and partial functional return. RS-61443 is highly effective as a primary immunosuppressant for hindlimb allotransplantation. The disturbing moderate rejection observed in CsA animals, which was absent with RS-61443, may significantly hamper function of transplanted limbs.

Animals↗

PubMed1993

The classification of flaps.

The history of flap surgery originated several thousands of years ago. As each era of humans learned to apply the principles of anatomy, progress was made in the coverage of difficult and complex wounds. A classification scheme is important not only to organize our thinking, but also to logically plan an operation based on reconstructive requirements. The most important factor in the safe design of flaps is a fundamental understanding of the anatomy based on the arterial supply.

Bone Transplantation↗

PubMed1993

Immediate flap coverage in the treatment of large surgical defects after tumor resection.

Fifty-one patients with large surgical defects after tumor resection (range of 100 to 1,050 centimeters squared, mean of 259 centimeters squared) were treated with immediate flap coverage. Indications for flaps were exposed vital structures, a wound bed unsuitable for skin grafting or planned postoperative radiation. Patients were divided into three groups based on tumor location--head and neck, trunk and perineum and groin and extremity. Sixty-eight flaps (11 free and 57 pedicled) were used and all wounds ultimately healed. Overall, extensive complications occurred in eight patients, lesser complications in 11 patients and initial flap loss in three patients. While complications delayed healing, all defects were ultimately successfully covered using flaps. Preferred flap choices for each anatomic area are presented. By providing immediate coverage of these massive defects, flaps allow wide tumor resection that improves palliation and chance for cure. Flaps tolerate postoperative radiation well and do not obscure recurrence if careful follow-up examination is given.

Adolescent↗

PubMed1992

Aeromonas hydrophila infections following use of medicinal leeches in replantation and flap surgery.

Aeromonas hydrophila infections are a recognized complication of postoperative leech application, and can occur with measurable frequency in populations of patients treated with leeches. We review 11 previously reported leech-related Aeromonas infections and analyze seven unreported cases. These infections range from minor wound complications to extensive tissue loss and sepsis. Often, these infections followed leech application to tissue with questionable arterial perfusion. Onset of clinical infection in these patients ranged from within 24 hours of leech application to 10 days or more after leech application. Late infections may represent bacterial invasion from colonized necrotic tissue. Based on these observations, we recommend that leech applications be restricted to tissue with arterial perfusion to minimize contamination of necrotic tissue. We also recommend that patients treated with leeches receive antibiotics effective against Aeromonas hydrophila before leech application. Patients treated with leeches and discharged with eschars or open wounds might benefit from oral antibiotic therapy until wound closure. These precautions may minimize or eliminate this complication of leech use.

Adolescent↗

PubMed1992

The course of the inferior alveolar neurovascular canal in relation to sliding genioplasty.

The anterior course of the inferior alveolar neurovascular canal was determined in 52 hemimandibles using high-resolution radiographs. Significant variability was found in its course. It was noted that if the osteotomies for sliding genioplasty were performed at least 6 mm below the inferior border of the mental foramen, injury to the mental nerve would be reduced.

Chin↗

PubMed1992

Arterial anatomy of the face: an analysis of vascular territories and perforating cutaneous vessels.

The cutaneous arterial circulation of the face and scalp was investigated by using multiple anatomic techniques in fresh cadaver specimens. Selective ink injections, dissection and measurement of latex-hardened perforators, and radiographic examination of transverse sections of barium-injected specimens defined 11 vascular territories of the face and scalp. Three distinct patterns of arterial vascularization were observed: (1) small, densely populated musculocutaneous perforating arteries supply the anterior face (facial, infraorbital arteries), (2) large, sparsely populated fasciocutaneous perforators that occur in predictable locations supply the lateral region of the face (branches of the transverse facial, submental, and zygomatico-orbital arteries), and (3) small, densely populated fasciocutaneous perforators supply the scalp (occipital, superficial temporal, and posterior auricular arteries). The locations of the perforation sites of the transverse facial, zygomatico-orbital, supratrochlear, supraorbital, and superficial temporal arteries may be predicted statistically within 2-cm limits with 95 percent certainty for individuals in the general population. The results of this study provide the anatomic framework to potentially revise or improve current reconstructive or aesthetic procedures on the face based on known arteries.

Adult↗

PubMed1992

Changing trends in the management of pelvic pressure ulcers: a 12-year review.

The purpose of this study was to evaluate the effect of a preferential shift toward increased use of muscle flap coverage for surgically treated Stage IV pelvic pressure ulcers. Patients treated from 1979-1990 were studied since 1979. Muscle flap use increased from 57% to 100% of surgically treated cases. Over this same period the number of operations per ulcer declined from 1.9 to 1.1 and the time to complete healing dropped from 12.8 to 4.8 weeks. While other factors (including advances in supportive care) have also played a role, increasing use and familiarity with muscle flap has been largely responsible for these improvements.

Adult↗

PubMed1991

An adverse wound environment activates leukocytes prematurely.

This study was designed to evaluate the effect of different wound environments on wound activation. Our wound model provided two distinct environments, a well vascularized musculocutaneous flap and a poorly perfused random-pattern flap, in miniature swine. Leukocytes were isolated and analyzed by the following three variables: surface and total cellular Mac-1 (CD11b/CD18), superoxide anion expression, and lactoferrin release. Leukocytes from the unfavorable, poorly oxygenated wound environment activate on entry into the wound. Leukocytes from the musculocutaneous flap wound are better able to respond to a maximal challenge with the phorbol ester, phorbol myristate acetate. These findings may account for the enhanced bactericidal actions of the musculocutaneous flap compared with the random-pattern flap observed clinically.

Animals↗

PubMed1991

Influence of radiotherapy on microvascular reconstruction in the head and neck region.

Over a 5-year period at the University of California San Francisco, 42 patients who required microvascular reconstruction for abnormalities in the head and neck area were identified. Twenty-four patients (Group I) underwent reconstruction for a variety of neoplastic and non-neoplastic conditions and did not receive radiotherapy. Eighteen patients (Group II) had undergone previous radiotherapy averaging 6,090 rads. The mean ages for Group I and II patients were 40.7 and 55.5 years, respectively. In Group I, 13 muscle, 7 fasciocutaneous, 4 osteocutaneous, and 2 jejunal transfers were performed. In Group II, 11 muscle, 5 fasciocutaneous, 3 osteocutaneous, and 2 jejunal transfers were performed. Flap survival at 3 months was 88% in Group I and 95% in Group II. Wound complication rates were similar in both groups (15% Group I, 19% Group II), as was donor site morbidity (15% Group I, 29% Group II). Operative times (10.9 hours Group I, 10.6 hours Group II) and median postoperative hospitalization (14 days Group I, 16 days Group II) were comparable as well. Four of the five patients in whom the flap procedures failed were subsequently treated by a second microvascular reconstruction. Previous irradiation of the recipient bed did not appear to affect the success of subsequent microvascular reconstruction or the difficulty of such reconstruction as judged by operative time.

Adult↗

PubMed1991

The muscle flap in the treatment of chronic lower extremity osteomyelitis: results in patients over 5 years after treatment.

Preliminary reports have indicated that debridement of the bony sequestrum followed by muscle-flap coverage allows successful treatment of chronic osteomyelitis. To determine the long-term effectiveness of this procedure, 34 consecutive patients with chronic osteomyelitis of the distal lower extremity treated with debridement, a 10- to 14-day course of culture-specific antibiotics, and immediate muscle-flap coverage were evaluated. Patients were treated from 1979 through 1984, and long-term (greater than 5 years) follow-up was available for 27 (79 percent). Twenty-three (85 percent) of these patients underwent microvascular muscle transplantation (gracilis or latissimus dorsi), and four underwent local muscle flaps (gastrocnemius or soleus) for immediate wound coverage. Twenty-four patients (89 percent) healed and were without recurrence over long-term (greater than 5 years, mean 7.4 years) follow-up. Of the three with recurrence, two were cured (greater than 5 years follow-up) after additional muscle-flap procedures. Thus the overall success rate was 96 percent, with a minimum 5-year follow-up. Guidelines for muscle-flap selection and treatment techniques in current use are presented. Debridement and immediate muscle-flap coverage provide effective, single-stage treatment of chronic osteomyelitic wounds and allow antibiotics to be restricted to short-term use. Furthermore, muscle flaps covered with skin grafts provide durable coverage while allowing subsequent ancillary procedures (i.e., bone grafts) to be performed under the flaps.

Adult↗

PubMed1991

Update on chronic osteomyelitis.

Recent advances in the understanding of the pathophysiology and treatment of osteomyelitis have been discussed. Some of the advances (in either knowledge or technology) that we have found particularly useful include the following: The discovery of additional prognostic factors, which allow more reliable preoperative assessment. The development of the Ilizarov device, which allows bone fixation and later limb lengthening. Confirmation of the effectiveness of single-staged debridement and muscle flap closure. Confirmation that a brief (10 to 14 day) course of antibiotics is as effective as more prolonged therapy. The development of several new free muscle donor sites and a greater appreciation of the need for careful insetting of the muscle. The development of local antibiotic delivery systems, especially continuous antibiotic irrigation catheters. The development of newer oral and intravenous antibiotics that allow outpatient therapy following surgery. The recognition that patients require extended follow-up, and that any recurrences can be successfully treated with a second debridement and muscle flap closure.

Animals↗

PubMed1990

Superoxide production by wound neutrophils. Evidence for increased activity of the NADPH oxidase.

Oxygen radical secretion by neutrophils is potentiated or "primed" by extravascular migration into wounds. To define this change in responsiveness more precisely we measured superoxide production by blood and wound neutrophils from rabbits using formylmethionyl-leucyl-phenylalanine and phorbol myristate acetate as agonists. In all experiments, the time- and dose-dependency of superoxide secretion were the same for blood and wound neutrophils. However, wound neutrophils produced significantly more superoxide. Furthermore, the cytochrome b component of the NADPH oxidase was found in greater quantities within wound neutrophils. We conclude that priming does little to alter the requirements for activating the NADPH oxidase but does significantly increase the velocity of superoxide generation. The data suggest that alterations in the assembly and function of the NADPH oxidase may contribute to enhanced superoxide secretion by wound neutrophils.

Animals↗

PubMed1990

The recalcitrant perineal wound after rectal extirpation. Applications of muscle flap closure.

Perineal wounds developing after abdominoperineal resection result in chronic purulent drainage and intermittent episodes of sepsis and are generally unresponsive to conservative medical and surgical treatment. Thirteen consecutive patients (aged 27 to 74 years; mean, 48 years) who underwent débridement and immediate muscle flap closure of these wounds were analyzed to identify risk factors for delayed healing and to evaluate the effectiveness of muscle flap coverage. Three risk factors were identified: preoperative or postoperative radiation therapy, resection for recurrent carcinoma, and inflammatory bowel disease. A total of 19 muscle flaps (11 gracilis, five gluteal thigh, two gluteus maximus, and one rectus abdominis) were used to close these wounds. During an average 3.5-year follow-up, four (31%) minor complications and one (8%) recurrence were noted to occur. Muscle flaps provide safe, effective, single-stage procedures for the closure of chronic perineal wounds.

Adult↗

PubMed1990

Rigid internal fixation vs. traditional techniques for the treatment of mandible fractures.

Treatment results were compared between mandibular fractures repaired with vitallium miniplates versus intermaxillary fixation (IMF) and wire osteosynthesis in 79 patients treated over a 4-year period. The postoperative courses of 35 patients treated with 46 plates were compared to those of 44 individuals treated with traditional reduction techniques. The plated group contained nine complications (26%) versus ten (23%) in the non-plated group. This difference was not statistically significant, despite the presence of more severe fractures in the plated group. Major complications (nonunions, malocclusions) were noted in only three (8%) of the plated group; there were six complications (14%) in the non-plated group. We conclude that the plating of mandibular fractures incurs no greater overall risk of complications than traditional methods of fixation, and a lower risk of major complications, and that the advantages of plate fixation, including decreased time of intermaxillary fixation and cost effectiveness, make this the method of choice in complex mandibular fractures, even in a high-risk population.

Adult↗