Biomedical subjects
Publications and source records attributed to C S Murakami.
This article focuses on three main areas, which includes an overview of skin anatomy, different types of skin flaps and their vascular supply, and several aspects of flap biomechanics to allow the surgeon to perform the most adequate reconstruction with regard to location and size of defects.
The cheek, one of the most important facial aesthetic units, adjoins key facial structures including the mouth, nose, and eyelids. When undertaking cutaneous cheek defect repair, these functional structures must remain undisturbed. Indeed, the size, depth, and position of each defect must be critically assessed in relation to surrounding donor tissue and landmarks. This article reviews cheek anatomy, surface landmarks, and the various surgical options for achieving successful aesthetic and functional repair.
Scars in the head and neck caused by trauma or extirpative surgery can present a significant problem to the patient and may require revision. A variety of techniques, both surgical and nonsurgical, exists for treatment of unsightly scars. Surgical excision of scars relies upon recruitment of local tissue for closure of the ensuing defect. Tissue expansion and serial scar excision may be used to provide more tissue for advancement or local flap coverage of revised scars. Herein we review the history, technique, and complications of tissue expansion and serial excision as well as the basic scientific principles underlying these techniques.
OBJECTIVE: Severe GI bleeding after hematopoietic cell transplantation is commonly due to lesions that are unusual in nontransplant patients. The frequency of GI bleeding appears to have decreased over the last decade, but the reasons have not been readily apparent. We sought to determine the incidence of severe bleeding during two time periods, to describe the causes and outcomes of bleeding, and to analyze the reasons behind an apparent decline in severe bleeding over the decade covered. METHODS: During 1986-1987 and 1996-1997, we followed all patients with and without severe bleeding at our institution, a marrow transplant center. RESULTS: Over this decade, the incidence of severe bleeding declined from 50/467 (10.7%) to 15/635 (2.4%) (p < 0.0001). Overall mortality from intestinal bleeding declined from 3.6% to 0.9% (p = 0.002), but mortality in those with bleeding remained high (34% vs 40%). The onset (day 42 vs 47) and platelet counts (35,994 vs 37,600/microl) were similar, but the sites and causes of bleeding were different. During 1986-1987, 27/50 patients bled from multiple GI sites, viral and fungal ulcers, or graft-versus-host disease (GVHD). Over the decade, bleeding from GVHD had decreased 80% (p < 0.0001), and bleeding from viral (p < 0.0001) and fungal (p = 0.023) ulcers almost disappeared. CONCLUSIONS: The incidence of severe GI bleeding has declined significantly over the last decade because of prevention of viral and fungal infections and severe acute GVHD. However, severe bleeding after transplant remains a highly morbid event, particularly among patients with GVHD.
BACKGROUND: Acute graft-versus-host disease (GVHD) of the liver is a frequent complication of allogeneic hematopoietic cell transplantation. This report describes hepatic GVHD following autologous transplantation. METHODS: We reviewed 116 consecutive autologous transplant recipients. A diagnosis of GVHD was based on histology (segmental to subtotal destruction of bile ductal epithelial cells with apoptosis and lymphocytic infiltrates), clinical criteria (elevated serum alkaline phosphatase), a response to immunosuppressive therapy, and finding no other cause for cholestatic liver disease. RESULTS: Two patients developed cholestatic liver disease (alkaline phosphatase levels over five times the normal upper limit) and had liver biopsies showing apoptotic and dysmorphic ductular epithelial cells typical of GVHD. Three additional patients developed cholestasis and intestinal symptoms but had gastric biopsies only, showing apoptotic crypt epithelial cells and crypt cell drop-out typical of GVHD. CONCLUSION: Two recipients of autologous hematopoietic cells developed histologic abnormalities of small bile ducts and cholestatic liver disease resembling GVHD of the liver after allogeneic transplant. The mechanisms of bile duct damage in this setting may involve immune dysregulation related to reconstitution of immunity with peripheral blood stem cells.
Patients who survive hematopoietic cell transplantation (HCT) have multiple risk factors for chronic liver disease, including hepatitis virus infection, iron overload, and chronic graft-versus-host disease (GVHD). We studied 3,721 patients who had survived 1 or more years after HCT at a single center and identified patients with histologic or clinical evidence of cirrhosis. Risk factors for the development of cirrhosis were evaluated and compared with a group of matched control subjects. Cirrhosis was identified in 31 of 3,721 patients surviving 1 or more years after HCT, 23 of 1,850 patients surviving 5 or more years, and in 19 of 860 patients surviving 10 or more years. Cumulative incidence after 10 years was estimated to be 0.6% and after 20 years was 3.8%. The median time from HCT to the diagnosis of cirrhosis was 10.1 years (range, 1.2 to 24.9 years). Twenty-three patients presented with complications of portal hypertension, and 1 presented with hepatocellular carcinoma. Thirteen patients have died from complications of liver disease, and 2 died of other causes. Three patients have undergone orthotopic liver transplantation. Hepatitis C virus infection was present in 25 of 31 (81%) of patients with cirrhosis and in 14 of 31 (45%) of controls (P =.01). Cirrhosis was attibutable to hepatitis C infection in 15 of 16 patients presenting more than 10 years after HCT. There was no difference in the prevalence of acute or chronic GVHD, duration of posttransplant immunosuppression, or posttransplant marrow iron stores between cases and controls. Cirrhosis is an important late complication of hematopoietic cell transplantation and in most cases is due to chronic hepatitis C. Long-term survivors should be evaluated for the presence of abnormal liver function and hepatitis virus infection.
Jaundice is a common problem in marrow transplant recipients. The incidence of bile duct obstruction in this setting is unknown. The purpose of this study was to determine the incidence of biliary obstruction, the causes, and outcomes following marrow transplant. Consecutive cases were reviewed at two major transplant centers in the United States from 1969 to 1996 at the Fred Hutchinson Cancer Research Center and 1989 to 1996 at the City of Hope National Medical Center. Nine cases of biliary obstruction were identified as a cause of jaundice in 7412 marrow transplant recipients, an incidence of 0.12%. The presentation was bimodal, with seven cases occurring prior to day 100 and two occurring 2 to 4 years after transplantation. The age distribution was 15 to 50 years and all patients had received allogeneic transplants. The causes of obstruction included gallbladder sludge (n=1), a duodenal hematoma (n=1), choledocholithiasis with biliary pancreatitis (n=1), bile duct infection (n=2), recurrent malignancy (n=1), choledocholithiasis associated with a benign stricture (n=1), Epstein-Barr virus-related lymphoproliferative disorder (n=1), and a benign stricture of unknown etiology (n=1). Biliary obstruction is a rare cause of jaundice in the post-transplant period. The presentation was similar to that of other post-transplant hepatobiliary problems, but with disparate causes.
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HYPOTHESIS: Transforming growth factor-beta1 (TGF-beta1) plus demineralized bone matrix (DBM) will reconstruct a critical mandibular defect devoid of periosteum in a canine model. STUDY DESIGN: Randomized, blinded, placebo-controlled, prospective animal pilot study. METHODS: Canine critical mandibular defects devoid of periosteum were reconstructed with DBM (group 1, n = 3) and DBM plus TGF-beta1 (250 microg TGF-beta1/g DBM) (group 2, n = 3). Radiologic, histologic, and biomechanical testing was performed on the test group and control group specimens at 12 weeks after implantation. RESULTS: A palpable bone bridge was present in the group 2 subjects 5 to 6 weeks after implantation and was never present in the group 1 subjects. Radiologic and histologic examination at the time of harvest (12 weeks after implantation) demonstrated a solid bone bridge in the group 2 subjects and a fibrous union in the group 1 subjects. Group 2 specimens demonstrated failure in four-point bending testing at an average maximum moment of 9.9 +/- 2.2 N-m. This value was 9.4% of the maximum moment of the contralateral nonoperated side. Group 1 specimens were palpably flexible on plate removal and had a biomechanical strength of 0. The difference in strength between group 1 and group 2 was statistically significant (P < 0.02), supporting the hypothesis that the addition of TGF-beta1 to the DBM carrier resulted in the formation of significantly stronger bone in the critical gap. CONCLUSION: The addition of TGF-beta1 to DBM results in healing of a critical bone defect devoid of periosteum in a higher mammalian model.
OBJECTIVE: To introduce and evaluate the technique of cirummandibular wires with piriform rim suspension (CMW-PRS) combined with arch bars and a fracture site bridle in the treatment of mixed-dentition pediatric mandible fractures. DESIGN: Five male patients (mean age, 8.2 years [age range, 7-10 years]) with an isolated mixed-dentition mandible fracture were treated with the CMW-PRS technique at the University of Texas Health Science Center, San Antonio, from 1985 to 1987 and at the University of Missouri, Columbia, from 1992 to 1995. Clinical and radiographic fracture healing, somatosensory status, and complications were evaluated. RESULTS: All patients demonstrated clinical union to their preinjury occlusion by 3 or 4 weeks. They remained without complications until they were no longer available for follow-up. Panoramic radiographs supported the findings of clinical examinations throughout the study, and no radiographic abnormalities were found. There were no somatosensory disturbances of the lingual or mental/inferior alveolar nerves. One patient required a tracheostomy unrelated to the procedure. CONCLUSION: The CMW-PRS technique combined with arch bars and a fracture site bridle wire achieved equivalent historical results when compared with the dental splint. The potential advantages and disadvantages of the CMW-PRS technique compared with those of monocortical bone plating, as well as the significant advantages of the CMW-PRS over the dental splint, are discussed in the text.
Large upper lip defects that include the surrounding aesthetic subunits of the midface are difficult to reconstruct. Abbé flaps have been a popular method of dealing with small upper lip defects but, as classically described, they are insufficient for larger defects. We performed cadaver injections to evaluate the vascular territory supplied by the inferior labial artery with particular attention to the submental area. Extended Abbé flaps were then designed and used in combined upper lip and midfacial reconstruction. Three cases and guidelines for the use of the extended Abbé flap are presented.
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Aberrant fibrous tissue formation after surgery or trauma still presents a challenge to surgeons. Current research hopes to identify the characteristics of the population of fibroblasts that lead to hypertrophic or keloid scar formation. Surgical procedures and laser therapy followed by intralesional steroid treatments still are the foundation of treatment; but new modalities are being applied. The pathogenesis and management of hypertrophic scars, keloids, and scar contractures are discussed in this article.
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Lidocaine with epinephrine is currently the most common local anesthetic agent used for facial soft tissue surgery. This combination is generally safe and effective in providing complete anesthesia and adequate hemostasis. Because epinephrine is unstable at physiologic pH, the commercial preparation is formulated with a low pH (3.5-5.5). Unfortunately, this acidic pH causes significant pain during infiltration. To reduce pain, clinicians sometimes buffer acidic local anesthetic agents with sodium bicarbonate. However, little is known about the stability of epinephrine when the pH of epinephrine is clinically altered. Using high pressure liquid chromatography (HPLC), epinephrine levels were measured after the addition of sodium bicarbonate. Our results indicate a significant amount of epinephrine degradation occurs in some of these specimens. Recommendations regarding the use of buffered local anesthetic agents are made.
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OBJECTIVE: To determine the safety and efficacy of ursodeoxycholic acid treatment in patients with chronic graft-versus-host disease (GVHD) of the liver. DESIGN: Open-label study in which each patient served as his or her own control. SETTING: Private practice and a university bone marrow transplant center. PATIENTS: Twelve patients with refractory chronic GVHD of the liver were studied after allogeneic bone marrow transplantation. INTERVENTIONS: After baseline data collection, patients were given ursodeoxycholic acid (UDCA, 10 to 15 mg/kg body weight per day) for 6 weeks. After discontinuation of the drug, patients were followed for an additional 6 weeks. Doses of immunosuppressive drugs were unchanged for these 12 weeks. MEASUREMENTS: Signs, symptoms, Karnofsky performance scores, hematocrit, total leukocyte count, absolute neutrophil count, platelet count, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, gamma-glutamyltransferase (GGT), total serum bilirubin, prothrombin time, serum creatinine, and blood urea nitrogen were assessed. RESULTS: Serum tests of cholestatic liver injury measured at 2, 4, and 6 weeks showed improvement compared with baseline. At 6 weeks, the percent decrease from baseline in total serum bilirubin was 33% (P less than 0.005); in alkaline phosphatase the decrease was 32% (P less than 0.038); and in AST the decrease was 37% (P less than 0.007). After discontinuation of UDCA therapy, 11 patients were followed for 6 additional weeks. All showed significant worsening in liver function test results. Symptom scores were unchanged throughout the study. One patient with pruritus improved while receiving therapy with UDCA. No adverse effects were observed. CONCLUSION: Therapy with UDCA was safe, well-tolerated, and efficacious in the short-term treatment of refractory chronic GVHD of the liver. Further investigation is needed to evaluate the long-term effects of UDCA therapy.