Biomedical subjects
Publications and source records attributed to H C Redman.
Infected bile lakes complicated orthotopic liver transplantation in two pediatric patients. Retransplantation was avoided by means of percutaneous transhepatic internal drainage of the bile lakes. Internal drainage maintained the enterohepatic cycle of cyclosporine and allowed the bile ducts to heal.
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The place of angiography in the diagnosis of arterial injuries in cases of penetrating wounds of the extremities has been a source of controversy, especially when the injury is in proximity to the artery but there is no clinical evidence of arterial injury. The positive yield of angiography has been reported to be between 6% and 20%, but most angiographers suspect the yield to be lower. The cost of angiography continues to increase. A retrospective analysis was performed in 507 patients with 534 possible arterial injuries associated with wounds near vessels. Thirty-one arteries were considered by the radiologist to have surgically significant injury. Seven patients did not have surgery. On the basis of surgical findings in 24 patients, there was a true-positive angiographic yield of 3.6% as well as five false-positive angiograms. Angiographic sensitivity was 100%, specificity 99%, accuracy 99%, positive predictive value 85%, and negative predictive value 100%. Ten (2.0%) minor angiographic complications and two (0.4%) major complications occurred. There were three surgical complications in negative surgeries. False-positive angiograms can probably be reduced by more circumspect evaluation of minor abnormalities. However, the 3.6% true-positive yield must be balanced against the complications of surgery and angiography and the associated costs. Although delayed diagnosis and therapy of arterial injury are less satisfactory than early repair, angiography of wounds in proximity to major extremity arteries should be reserved for situations in which exclusion of injury is critical to overall management of the patient.
The change in the position of the kidney during percutaneous nephrostomy is a major concern to urologists who participate in percutaneous stone removal. We report that the majority of kidneys ascend an average of 2.2 cm. when the patient turns from a supine to a prone position. This change in position is more marked on the right side and is more common in male patients. Knowledge of this anatomical variation is important to determine which patients are suitable candidates for percutaneous nephrostolithotomy and to plan a percutaneous approach to a renal or ureteral calculus.
Technical advances and operator experience have resulted in a rapid and marked streamlining of the percutaneous approach to renal calculi. The development of nephrostomy tract balloon dilators, improved grasping instruments and the use of assisted local anesthesia have been integral in reducing the morbidity and cost of the procedure. We report our initial favorable experience in the use of percutaneous stone removal on an outpatient basis. All 5 patients underwent an uncomplicated 1-stage stone removal. Cost for outpatient percutaneous stone removal was substantially less than for surgery or extracorporeal shock wave lithotripsy.
Eight patients with angiographically proved arteriovenous malformations (AVMs) of the extremities (seven congenital, one posttraumatic) were evaluated with magnetic resonance (MR) imaging using a 0.35-T superconducting system and spin-echo pulse sequences. Congenital AVMs appeared as accumulations of dilated tortuous blood vessels infiltrating the involved muscles. A posttraumatic acquired AVM of the shoulder consisted of a large feeding artery associated with a pseudoaneurysm and a soft-tissue mass. MR imaging allowed precise anatomic localization and provided details concerning the size and extent of the AVMs. The relationship of AVMs to specific muscle groups, bones, and vascular structures could be accurately determined. Although major feeding and draining vessels were identified, the exact arteries and veins supplying and draining the AVM could not be ascertained. Images obtained in the transverse plane consistently yielded the most useful information. MR imaging and angiography may be complementary techniques in the initial evaluation, follow-up, and treatment planning of AVMs of the extremities.
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Magnetic resonance imaging (MRI) was performed on nine patients with hepatic cirrhosis and portal hypertension after selective distal splenorenal shunt for decompression of bleeding esophageal varices. MRI demonstrated the splenorenal anastomosis and patency of the shunt, splenic vein, and left renal vein in each case. Imaging in the transverse plane provided optimal visualization of the shunts. The authors conclude that MRI is a safe, noninvasive technique for the postoperative evaluation of selective distal splenorenal shunts.
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Preoperative and postoperative evaluation of the patient with a splenorenal shunt usually requires angiography. Magnetic resonance imaging is a safe technique that can provide information concerning vascular anatomy and shunt patency without the potential hazards of catheterization and iodinated contrast medium.
Magnetic resonance (MR) imaging studies of the upper abdomen have been difficult to interpret due to the frequent inability to differentiate between various structures, especially between the gastrointestinal tract and adjacent normal and pathological structures. Utilizing effervescent granules and intravenous glucagon, gas in the stomach and duodenum provides excellent contrast and results in improved MR imaging of the upper abdomen. This technique is useful in demonstrating both gastric and pancreatic morphology.
Routine radiography plays little role in the current diagnosis of pancreatic carcinoma, though some studies may be of use in treatment planning for specific patients. CT scanning is an important tool in the diagnosis of symptomatic pancreatic carcinoma. With present technology it is not a survey technique because lesions that do not deform the pancreatic contour are generally missed. Development of more sophisticated scanners or pancreatic-specific x-ray dyes may change this. At present, CT should be used in diagnosis and treatment planning for symptomatic patients either in conjunction with other tests or as the primary diagnostic procedure, depending upon the problems presented by the individual patient.
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Ammonia concentrations in 2.8 m3 chronic inhalation exposure chambers housing either 144 rats or 360 mice were measured by ion chromatography and chemiluminescence to evaluate chamber maintenance procedures. Variables included use of bacteriostatic cageboard, air flow rate, animal species, and age. Ammonia concentrations were lowered by using bacteriostatic cageboard and were inversely proportional to cageboard changing frequency and air flow rate.
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This study evaluates neonatal and postneonatal survival of Macaca radiata to 180 days of age at the California Primate Research Center from 1966 through 1973. Of a total of 287 live births, infant mortality rates (IMR) for three different types of housing were significantly different: 12% for inside cages, 41% for an outside one-half-acre enclosure and 31% for outside corncrib cages. Experience of the female in raising an infant to weaning age was a significant determinant only for the outside housing IMR. Introduction of laboratory-reared females into the breeding colony made the maternal breeding experience an important factor.
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Many of the diseases of the chest wall, heart, mediastinum, pleura and lungs can be successfully imaged by computerized tomography. Radiation therapy ports can be calculated and transcutaneous biopsies monitored. This paper deals with the many uses that we have had for computerized tomography in assessing diseases within the chest and thorax.