Biomedical subjects
Publications and source records attributed to L G Martin.
Primary hepatolithiasis, although rare, is a difficult condition requiring the combined management of radiology and surgery. Use of extracorporeal shock wave lithotripsy and percutaneous stone extraction, along with improved biliary drainage by choledochojejunostomy, should provide a safe effective approach to this unusual problem.
Peripheral arterial thromboembolism and thrombosis of arterial grafts continue to threaten viability of extremities. Percutaneous intra-arterial thrombolysis (IAT) and angiodilatation have afforded limb salvage in some of these patients. Proper patient selection appears to be the hallmark of success with IAT. During a recent three-year period, we used IAT in 32 extremities in 28 patients who had acute arterial insufficiency. Before IAT, 16 extremities were painful at rest, and 16 had incapacitating claudication. The overall success rate was 38%, but some degree of thrombolysis occurred in 88%. Limb salvage was achieved in 27 of 32 extremities (84%). Only five of 17 limbs (29%) with arterial graft thrombosis required no operation or an operation of lesser magnitude than predicted before IAT. Of six extremities with native arterial embolism, four (67%) were completely cleared with IAT. Major complications occurred in eight cases (25%), with two IAT-related deaths (6%). This study suggests that IAT is best reserved for individuals with acute limb ischemia caused by arterial embolus, those whose degree of ischemia would tolerate a 24-hour trial of IAT, and those whose femoral or tibial runoff is not likely to require remedial operation.
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Retained intrahepatic biliary stones were dislodged with and crushed between two occlusion balloon catheters. Standard angiographic catheters and guide wires with exchange for occlusion balloon catheters can be used in situations where a stone basket cannot, and have certain advantages over Fogarty biliary balloon catheters.
Use of an everting thru-lumen balloon catheter allowed successful percutaneous transluminal cholangioplasty in a patient with sclerosing cholangitis when conventional methods had failed. The catheter we used was a prototype; however, further refinements are planned, and we feel this will be a useful tool in a variety of interventional procedures.
In 200 consecutive patients undergoing percutaneous transluminal renal angioplasty (PTRA), a significant increase in primary success rate (P less than .02) and a concomitant decrease in complications were noted in the second 100 patients. The primary success rate increased from 93% to 97%, and the incidence of total complications fell from 20% to 13%. The incidence of complications requiring surgery fell from 5% to 2%, and the incidence of renal failure declined from 10% to 5% of the patient population. Variables that contributed to improvement in the procedure included new approaches to crossing arterial stenoses, increased use of digital imaging, less contrast material used in each case, better hydration of patients, and increased use of vascular sheaths at the puncture site.
Ascites, hepatomegaly, and abdominal pain constitute the classic triad of the Budd-Chiari syndrome of hepatic-vein or inferior-vena-cava obstruction. This condition was first mentioned by Budd in the mid 1800s and additional information was provided by Chiari in the 1890s. In nearly two-thirds of patients the exact etiology cannot be determined. The syndrome has, however, been associated with hypercoagulable states, neoplasms, trauma, medications, and congenital abnormalities. The diagnosis is difficult to make clinically; therefore, radiology plays a critical role in the workup of these patients. Nuclear medicine, sonography, CT, angiography, and MRI all provide valuable diagnostic information. These data combined with hepatic biopsy determine which patients should be treated by percutaneous angioplasty or surgery, and also determine the type of shunt to be performed (such as the mesoatrial shunt when the inferior vena cava is occluded or severely compressed). Noninvasive imaging is also useful in the follow-up of patients after both percutaneous angioplasty and surgery.
Between January 1980 and July 1983, percutaneous transluminal angioplasty was attempted on 137 stenotic renal arteries in 100 patients. At termination of follow-up studies (3-39 months, mean of 16 months), 70% of those treated for hypertension had benefited from the procedure. Stenosis secondary to fibromuscular dysplasia responded better than stenosis from arteriosclerosis (85% and 65% of the patients, respectively). Benefit was minimal for those with stenosis of the renal artery ostium or renal insufficiency. Determining levels of renal vein renin before angioplasty is helpful in selecting patients; following angioplasty, this has considerable significance in predicting the success of the procedure.
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We have studied the thyroid function of high-altitude-acclimated (6,900 m for 5 wk) and nonaltitude-acclimated control (198 m) rats. After 5 wk of high-altitude exposure the plasma concentrations of both thyroxine (T4) and triiodothyronine (T3) were lower than those in control rats (4.7 +/- 0.3 vs. 3.3 +/- 0.2 microgram/dl and 96 +/- 5 vs. 74 +/- 6 ng/dl, respectively). The plasma thyrotropin (TSH) concentration was elevated in the high-altitude-acclimated rats compared with controls (52 +/- 4 vs. 29 +/- 3 micrograms/dl, respectively). Gross anatomical (thyroid wt/body wt) and histological observations of thyroid tissue were consistent with elevated plasma TSH concentrations. These results suggest that the fall in the plasma concentrations of T4 and T3 during acclimation to severe hypoxia is due to a primary block of thyroid secretion and not to a fall in plasma TSH levels.
Two non-dialyzed patients with severe uremic bone disease were treated successfully with dihydrotachysterol (DHT). In each case, dramatic clinical improvement was noted in several weeks and this was verified by biochemical, radiologic and histologic measurements. Although DHT has been utilized previously in combination with dialysis, its documented effectiveness in the absence of the latter therapy has not previously been reported.
We present a case of Nelson's syndrome in which the clinical, radiographic, and surgical findings are indicative of a discrete microadenoma rather than of diffuse pituitary hyperplasia. Ultrastructural analysis reveals this to be the first example of a sparsely granulated lesion in Nelson's syndrome and only the second such adrenocorticotropic hormone-secreting tumor reported. Unfortunately, there do not seem to be any firm ultrastructural features that differentiate between hyperplasia and discrete adenoma. Separation of the two entities may be important in delineating the pathogenesis and treatment of Nelson's syndrome; these are discussed.
The response of plasma growth hormone (GH) to insulin-induced hypoglycaemia (IIH) and arginine infusion (AI) was studied in 22 young males (ages 8 to 17 years) with short atature and absent or delayed sexual maturation, before and after androgen administration. During initial evaluation, 5 patients had blunted GH response to IIH, 12 responded subnormally to AI and 4 failed to respond normally to either stimulus. These same studies were repeated in each patient following androgen administration. The source of androgen was as follows: a) 5 days of testosterone propionate (25 mg intramuscularly daily) in 20 patients. b) Methyltestosterone, 10 mg t.i.d. orally for four days in the other 2 subjects. In almost every case, androgen administration resulted in raising the levels of fasting GH and enhancement of the GH responses to IIH and AI was observed. Patients manifesting subnormal GH responses to these stimuli before androgen consistently demonstrated a normal response when challenged with identical stimuli during androgen administration. Growth velocities during the year following these studies were significantly increased in most instances and the growth spurts correlated well with the progression of sexual maturation. Sustained improvement in the GH responses to IIH and AI were uniformly observed in 3 patients when repetitive studies were performed 8 to 12 months later during spontaneous advancing sexual development. The results indicate that brief androgen administration can be helpful in delineating the cause of growth retardation in boys with short stature and delayed sexual maturation, particularly when the diagnosis of isolated growth hormone deficiency is suspected. They also offer prognostic value in determining growth potential in this same group of young males.
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