Biomedical subjects
Publications and source records attributed to H A Mitty.
During the last 20 years percutaneous nephrostomy has evolved as one of the basic procedures in the management of obstructive uropathy. This procedure is now widely available, it is relatively safe, and it offers rapid treatment of urinary obstruction regardless of underlying cause. Percutaneous nephrostomy is also the first step in a variety of antegrade ureteral procedures, including stent placement and ureteral dilation.
The Wallstent biliary endoprosthesis has recently been approved for treatment of malignant bile duct obstruction. Although minor changes in position have occurred, migration of these stents has been uncommon. The authors report a case in which migration occurred when stents were simultaneously deployed in the right and left bile ducts. Several mechanisms for this complication are postulated.
The so-called hypertrophic column of Bertin is a normal variation and simply represents unresorbed polar parenchyma of one or both of the two subkidneys that fuse to form a normal kidney. It contains renal cortex, pyramids, and columns (septa) of Bertin. (Since all elements of the tissue are normal, that is, neither hypertrophic nor a displaced or embryonic rest, it is referred to as "junctional parenchyma.") When a masslike lesion is suspected at sonography or excretory urography, diagnosis of junctional parenchyma can be made with a high degree of certainty when sonography shows that the structure (a) is located between the overlapping portion of two renal sinus systems, (b) is bordered by a junctional parenchymal line and defect, (c) contains renal cortex, pyramids, and columns of Bertin, and (d) contains renal cortex that is continuous with the adjacent renal cortex of the same subkidney.
Milk of calcium (MOC) in a small renal cyst or calyceal diverticulum is quite common. Ninety-one small renal cysts with MOC in 61 patients were found within a period of 4 years and 7 months. The main sonographic features are echogenic material layering in the dependent portion of a cyst, associated with reverberation echoes without shadowing. Shadowing was seen when MOC was present in larger amounts. Because MOC is usually asymptomatic and requires no treatment, differentiation from other lesions such as calculi or angiomyolipomas is important for proper patient management. MOC is detected more readily by ultrasonography than by radiography or CT.
Transhepatic cholangiography is commonly performed during postoperative evaluation of liver transplant patients. The authors describe a potential pitfall in the interpretation of these studies and illustrate that dilated interrupted lymphatics of the donor liver can mimic a periductal leak of contrast material.
Routine preoperative angiograms obtained in 97 consecutive patients with bone and soft-tissue tumors of the extremities were retrospectively reviewed to determine the role of angiography in surgical planning. Some degree of major vessel displacement was demonstrated in 51 patients. Encasement of major vessels, which precluded limb-salvage surgery, was seen in five of 76 bone tumors and in three of 21 soft-tissue tumors. All five patients with osteochondromas had associated vessel occlusion or compromise. For surgical planning, the demonstration of adequate anastomoses in the arches of the hands and feet is important, as branches of brachial and popliteal arteries may have to be sacrificed during limb-tumor surgery. Angiographic findings indicated or supported the need for a vascular surgeon in five cases in this series. Preoperative angiography provides important information with regard to the status of the vasculature and therefore is essential in the management of bone and soft-tissue tumors of the extremities.
A 20-gauge Chiba needle with a stylet embedded with polyvinyldifluoride (PVDF), a polymer that acts as an acoustic-electric transducer, facilitated a variety of diagnostic and therapeutic ultrasound (US)-guided interventions in nine patients. PVDF receives acoustic energy from the US scanner and transmits an electrical signal through the stylet and a shielded cable to the scanner, which results in appearance of a bright echo on the monitor at the location of the needle tip.
A case of renal angiomyolipoma is reported, in which embolotherapy was followed by liquefaction of virtually the entire tumor. The liquified lesion was drained percutaneously.
Systemic adverse reactions to iodinated radiographic contrast material are infrequent but can be dramatic. The number of patients experiencing such reactions can be minimized by selecting the most appropriate diagnostic study for each patient and by identifying patients at increased risk. Pretreatment with corticosteroids and use of low-osmolality contrast materials can minimize the number of severe reactions in high-risk patients.
Successful recanalization of isolated femoropopliteal occlusions by laser-assisted balloon angioplasty has been widely reported. However, the utility of this approach in other sites remains undetermined. The potential of laser-assisted balloon angioplasty in the treatment of a broad spectrum of lower extremity atherosclerosis was explored. Seventy-seven limbs in 69 patients were treated with laser-assisted balloon angioplasty by means of a percutaneous approach. Technical success was achieved in 62/77 (81%), with 52/77 (68%) open at discharge. At a mean of 8.6 months' follow-up, cumulative patency was 50% at 6 months and 42% at 9 months. In 10 cases initial guide wire placement was not possible; primary laser probe passage was technically successful in six, with two open at latest follow-up. Eleven patients underwent laser therapy without balloon angioplasty of distal sites with technical success in eight; at most recent follow-up five were open at the site of sole laser therapy. Complications were frequent. Bleeding requiring transfusion occurred in six, with three patients requiring emergency surgery; worsened ischemia necessitating urgent arterial bypass grafting developed in five patients. In this series laser angioplasty carried significant complications and a high failure rate. Widespread application of this procedure should await further clinical investigation.
The current status of adrenal vein sampling and the role of adrenal gland percutaneous biopsy will be reviewed.
Laser-assisted balloon angioplasty has been successfully performed in peripheral and coronary arteries; however, the ability to perform laser angioplasty alone without the need for subsequent balloon angioplasty has not been reported. In the present series, infrapopliteal and below-knee popliteal sole laser thermal angioplasty was successfully performed on 14 of 16 (88%) lesions in 10 patients. Initial clinical and hemodynamic improvement was observed in seven of 10 (70%) patients, with clinical failure noted in three nonsurgical candidates with poor distal vessel runoff. Short-term clinical follow-up (mean, 6 months) revealed 100% patency at the site of laser thermal angioplasty. Clinical success was maintained in five of seven (71%) patients; symptoms recurred in two patients who had undergone laser thermal angioplasty and adjuvant balloon angioplasty of superficial femoral artery lesions. Treatment of distal peripheral arterial lesions with laser thermal angioplasty alone is feasible; studies comparing it with conventional balloon angioplasty should be considered.
The laser catheter is a nylon vascular catheter with a metal tip that has an end hole as well as side holes. The metal tip is heated by laser energy delivered through an optical fiber embedded in the catheter wall. The catheter may be advanced over a guidewire for use as an adjunct to balloon angioplasty or for use in smaller vessels as the exclusive method of recanalization. We used the catheter to treat 34 patients with 54 discrete vascular lesions in 35 extremities. Twenty patients were treated for clinically significant claudication and 14 for ischemic changes. Laser catheter-assisted balloon angioplasty was used to treat six iliac artery occlusions, two iliac artery stenoses, 10 superficial femoral artery occlusions, 12 superficial femoral stenoses, four popliteal artery occlusions, and three popliteal stenoses. Initial technical and clinical success in these patients, with follow-up periods of 3-6 months, was equivalent to the results of previous reports of laser probe-assisted balloon angioplasty. In 11 patients, 15 of 17 popliteal or tibial-peroneal lesions were treated with the laser catheter without subsequent balloon angioplasty. The treatment was successful in eight of these patients, with follow-ups for up to 6 months. Our results suggest that the laser catheter is a useful device for the treatment of vascular stenosis or occlusion when used either as an adjunct to balloon angioplasty or in smaller vessels as the exclusive method for angioplasty.
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Penile prostheses represent the most often used approach to the surgical management of impotence. These devices can be classified into semirigid and inflatable types. The advantages and disadvantages of each type as well as a description of their construction are provided here. Appropriate images are provided to illustrate the components of the various devices available.
Selective adrenal vein catheterization was done preoperatively in 11 patients with Cushing's syndrome owing to either an adrenal adenoma (6) or an adrenal carcinoma (5). Peripheral and adrenal venous blood (tumor side) was analyzed for progesterone, 17-hydroxyprogesterone, testosterone, delta-4-androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate, cortisol and 11-deoxycortisol. Comparisons were made of the ratios of precursors to products in the androgen and cortisol production pathways. In adrenal vein samples, cortisol levels were higher in the adenoma patients (p equals 0.06). These patients had a higher ratio of 17-hydroxyprogesterone to delta-4-androstenedione (p less than 0.04). The ratio of 11-deoxycortisol to cortisol was higher in the carcinoma patients (p less than 0.02). In the peripheral samples, the carcinoma patients had higher levels of testosterone and 11-deoxycortisol (p less than 0.02) and progesterone (p equals 0.05). The most striking differences were in the peripheral levels of 17-hydroxyprogesterone, delta-4-androstenedione and dehydroepiandrosterone, which were 10 to 20 times higher in the carcinoma group (p less than 0.005). The ratios of progesterone to 17-hydroxyprogesterone and 17-hydroxyprogesterone to 11-deoxycortisol were higher in the adenoma group (p less than 0.005 and p equals 0.06, respectively). The peripheral blood ratio of 11-deoxycortisol to cortisol was higher in the carcinoma group (p less than 0.03). These data indicate that peripheral and adrenal venous steroid levels and ratios of precursors to products are significantly different in the 2 groups. The carcinomas have a block in the conversion of 11-deoxycortisol to cortisol with a subsequent accumulation in androgen and cortisol precursors. The elevations in 17-hydroxyprogesterone, delta-4-androstenedione and dehydroepiandrosterone, and in the ratio of 11-deoxycortisol to cortisol in the carcinoma group are most striking in the periphery. Peripheral blood steroid measurement in patients with Cushing's syndrome and an adrenal mass aids in the preoperative differentiation of carcinoma from adenoma.