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Biomedical subjects

M T Han

Publications and source records attributed to M T Han.

14 recordsLinked to original sources
PubMed1995

Differential effect of the retropleural and retroperitoneal environments on healing of the inner wall of porous fabric prostheses in the thoracic and abdominal aorta of the same dog.

Healing of the inner wall of the same preclotted knitted Dacron arterial prostheses was compared in the descending thoracic aorta (DTA) and the abdominal aorta (AA) of the same dog. Each of 16 dogs received this dual implantation with study periods of 4 weeks for five dogs, 8 weeks for five dogs, and 16 weeks for six dogs. Healing was studied with light microscopy, scanning electron microscopy, transmission electron microscopy, and immunocytochemistry identification. The outer capsule was firmly adherent to the Dacron framework of all grafts implanted in the DTA; advanced healing of the inner wall of all thoracic grafts was present by 4 weeks, nearly complete healing by 8 weeks, and complete healing by 16 weeks. In contrast, the outer capsule was either not attached or only loosely adherent to the Dacron framework in eight AA grafts (50%), and in these implants no healing of the inner wall occurred beyond the limited perianastomotic pannus zone. In the other eight implants in which the outer capsule was firmly adherent to the Dacron framework, healing was roughly comparable to that in the grafts implanted in the DTA. This study demonstrated that (1) DTA grafts heal faster and more completely than AA grafts, (2) healing and endothelialization are related to the tightness of the outer capsule, (3) there is a high incidence of loose tissue attachment in the AA, and (4) healing of aortic grafts is site specific.

Animals↗
PubMed1995

Repair of neonatal aortic coarctation.

From 1981 to 1991, 146 infants under 1 month of age underwent repair of aortic coarctation. Forty-two had isolated coarctation, 53 had associated ventricular septal defect, and 51 had complex cardiac defects. The principal mode of presentation was congestive heart failure. The mean age at operation was 10.6 days. The technique for repair was left subclavian artery flap angioplasty in 126, resection with end-to-end anastomosis in 14, and a variety of repairs in 6 patients. Concomitant pulmonary artery banding was performed in 62 patients. The overall hospital mortality rate was 11%, and there was a strong association with pre-existing renal failure. The mean aortic clamp time in survivors was 23.9 minutes; mean hospital stay was 13.4 days. Significant restenosis occurred in 16 patients (11%) with an incidence of 10% after subclavian artery flap angioplasty. Eleven patients have undergone reoperation, and 5 were managed successfully with balloon dilatation.

Anastomosis, Surgical↗
PubMed1993

Double aortic arch causing tracheoesophageal compression.

Since 1972, 17 patients have been surgically treated for double aortic arch at our institution. The procedure became necessary before 12 months of age in 11 patients and before 24 months in 16 patients. The major symptoms were respiratory distress, noisy breathing, and respiratory infections; four patients also had dysphagia. A high degree of clinical suspicion should warrant further investigation. Barium swallow and bronchoscopy were diagnostic and revealed extrinsic compression of the esophagus and trachea, respectively. Division of the anterior arch was performed in 16 patients; the right (posterior) arch was divided in the remaining patient. Kommerell's diverticulum was found in four patients and was resected in order to avoid recurrence of dysphagia by compression. A vascular suspension procedure was necessary in 13 patients to further release the trachea and esophagus. There was no mortality in this series, and symptomatic improvement was achieved in all patients. A degree of tracheomalacia may be responsible for some residual symptoms in four patients.

Adolescent↗
PubMed1991

Ileocolic replacement of esophagus in children with esophageal stricture.

Between 1970 and 1988, 12 restrosternal esophageal substitutions using an ileocolic interposition were performed. The ages of the 12 children ranged from 2 to 6 years. In 11 children the esophageal strictures were secondary to ingestion of caustic liquid. All patients had failed esophageal dilation therapy. One death occurred on the 7th postoperative day following an episode of cardiac arrest at surgery. Early postoperative complications included three cervical ileoesophageal anastomotic leaks, which healed spontaneously. One patient had gastrointestinal bleeding 10 years postoperatively. This was controlled by antacid therapy without recurrence. Redundancy of the interpositioned ileocolic segment was observed in three children. All 11 surviving patients can eat a normal diet and have normal growth and development.

Anastomosis, Surgical↗
PubMed1986

[Carcinoma of the extrahepatic bile duct in young child--a case report].

A child, 2 years old, male suffering from severe jaundice, melena, severe anemia and right upper abdominal mass was admitted into our hospital. Diagnosis of obstructive jaundice was made before operation. On exploration, a tumor mass was found in the pancreatic head, which involved the duodenum and distal common bile duct. Pancreaticoduodenectomy with one stage pancreaticojejunostomy, choledochojejunostomy and gastrojejunostomy was carried out. Postoperative pathology showed adenocarcinoma of the distal common bile duct invading the periampullary tissues of the duodenum and infiltrating, to a lesser extent, into the pancreatic head. Carcinoma arising from the distal common bile duct is rare in infancy and childhood. Radical resection should be attempted if possible. In general, the prognosis is poor in this tumor. No complication after operation occurred on this patient but close follow-up is necessary. Pathology related to this tumor is discussed with a review of literature.

Adenocarcinoma↗
PubMed1982

Primary mediastinal tumors in children.

Mediastinal masses in children constitute a heterogeneous group of malignant and benign neoplasms. The majority of malignant tumors in our series of 188 children with a mediastinal mass were Hodgkin's and non-Hodgkin's lymphoma (87 patients) arising in the anterior and middle mediastinum. Ganglioneuroma (17) arising in the posterior mediastinum made up the bulk of benign tumors (52). Infants less than 2 yr old presented with symptoms of tracheal compression, whereas older children had fewer symptoms but a far greater likelihood of having a malignancy. In the assessment of patients with mediastinal tumors, the posteroanterior and lateral chest roentgenograms were most often diagnostic, and computed tomography of the chest provided the most information concerning preoperative resectability. The excellent survival of patients with stage I and II Hodgkin's disease reflects the radiosensitivity of the tumor; in our series of 33 patients, survival was not increased by radical resection. Unlike lymphomatous tumors, neurogenic masses should be completely excised. When initial exploration reveals unresectability, biopsy followed by radiation therapy and second-look excision of the tumor can be accomplished. In patients with primary mediastinal sarcomas, total resection should be carried out if possible. In our series, adjuvant radiation therapy or chemotherapy was effective in only 1 of 15 children with sarcoma. Surgical treatment of all mediastinal masses except lymphoma should be complete excision. In cases of suspected lymphoma, cervical or supraclavicular node biopsy can yield adequate tissue for diagnosis.

Adolescent↗
PubMed1981

Aggressive thoracotomy for pulmonary metastatic osteogenic sarcoma in children and young adolescents.

During a 6-yr period, 57 children and young adults less than 21 yr of age underwent 111 thoracotomies for pulmonary metastatic osteogenic sarcoma. Follow-up after the initial thoracotomy averaged 36.8 no and ranged from 1 to 78 mo. Twenty-eight patients (49%) underwent more than one thoracotomy--the number of multiple thoracotomies averaged 2.9 and ranged from two to eight. Twenty-six of the 57 patients are currently alive, and 25 of these are free of disease. Median survival was 36 mo. Actuarial survival curves demonstrated a 5-yr survival of approximately 40%. Seventy-one percent of patients who had a tumor-free interval of greater than 1 yr are currently alive, compared with 39% of patients who had a tumor-free interval of less than 1 yr. Patients with disease confined to one lobe at the initial thoracotomy had a better survival (64%) than patients with diffuse or bilateral disease (41%). An aggressive surgical approach toward osteogenic sarcoma with pulmonary metastasis thus appears to be justified.

Actuarial Analysis↗