Kyung J. Cho

The dissected aorta: Percutaneous treatment of ischemic complications - Principles and results

PURPOSE Describe the principles and results of percutaneous treatment of ischemic complications of aortic dissection. MATERIALS AND METHODS Twenty-four patients with aortic dissection complicated by ischemic compromise of the liver or bowel (n = 15), kidney (n = 18), or lower extremity (n = 13) were evaluated by means of aortography, intravascular ultrasound, and manometry, and were treated percutaneously. Visceral arteries were classified as obstructed or nonobstructed. Obstruction was classified as static, in which the dissecting hematoma extended into and narrowed the lumen of a branch artery, or dynamic, in which the dissection flap prolapsed into the vessel origin or narrowed the true lumen (TL) above it. Treatment consisted of vascular stents alone (n = 4), or balloon fenestration (n = 20) without (n = 8) or with (n = 12) vascular stents. RESULTS Obstruction was present in 77 arteries and was static in 12 arteries, dynamic in 45 arteries, static and dynamic in 17 arteries, and indeterminate in three arteries. Percutaneous treatment did not alter false lumen (FL) pressure, but reduced the peak systolic interluminal pressure gradient from 28 mm Hg to 2 mm Hg and restored flow in 71 of 77 arteries (92%). Six patients died within 30 days (25% operative mortality), none as a result of the procedure. Two additional patients died in follow-up from complications of an expanding FL. Technical complications in two patients due to altered hemodynamics after initial intervention were recognized and corrected percutaneously during the same procedure. CONCLUSIONS Percutaneous fenestration and endovascular stent deployment are indicated to restore blood flow to arteries compromised by aortic dissection. The prognosis of patients is related to the ischemic injury sustained prior to the percutaneous interventional procedure and, in patients with acute type I dissection who have not undergone surgery, to the preoperative stability of the FL.

Gadolinium-enhanced magnetic resonance angiography of abdominal aortic aneurysms.

PURPOSE The objective of this study was to assess the usefulness of gadolinum-enhanced magnetic resonance angiography (MRA) for defining anatomic features relevant to performing aortic surgery for aneurysmal disease. METHODS Anatomic data defined by MRA, including abdominal aortic aneurysm (AAA) size and character, as well as the status of the celiac, mesenteric, renal, and iliac arteries, were correlated with angiography, ultrasonography, computed tomography, or operative data in 43 patients. Five MRA sequences were obtained in an hour-long examination optimized for aortoiliac, splanchnic, and renal artery imaging at 1.5 T in a body coil. Four of the sequences were performed during or after infusion of gadolinium to improve image quality. RESULTS MRA correctly defined the maximum aneurysm diameter, as well as its proximal and distal extent in all patients. MRA detected 33 of 35 significant stenoses among 153 splanchnic, renal, or iliac branches examined (sensitivity = 94% and specificity = 98%). MRA did not resolve the degree of aortic branch stenotic disease sufficiently to precisely grade its severity. MRA did not reliably define the status of the inferior mesenteric artery, lumbar arteries or internal iliac arteries. One ruptured AAA and one inflammatory AAA were correctly diagnosed by MRA. No patient had a contrast reaction or contrast-induced renal toxicity related to administration of gadolinium. CONCLUSION Gadolinium-enhanced MRA of AAA provides appropriate, essential anatomic information for aortic reconstructive surgery in a 1-hour examination devoid of contrast-related renal toxicity or catheterization-related complications attending conventional arteriography.

Results of a multicenter study of the modified hook-titanium Greenfield filter

Initial efforts to modify the stainless steel Greenfield filter for percutaneous insertion led to development of a titanium Greenfield filter, which could be inserted by use of a 12F carrier. This device functioned well as a filter but had an unacceptable 30% rate of migration, tilting, and penetration. Therefore a titanium Greenfield filter with modified hooks was developed and has been tested in 186 patients at 10 institutions. Successful placement occurred in 181 (97%); placement of the remainder was precluded by unfavorable anatomy. A contraindication to anticoagulation was the most frequent indication for insertion (75%). All but two were inserted percutaneously, predominantly via the right femoral vein (70%). Initial incomplete opening was seen in four patients (2%), which was corrected by guide wire manipulation and asymmetry of the legs in 10 (5.4%). Insertion site hematoma occurred in one patient, and apical penetration of the cava during insertion occurred in a second patient. Both events were without sequelae. Follow-up examinations were performed at 30 days at which time 35 deaths had occurred. Recurrent embolism was suspected in six patients (3%) and two of three deaths were confirmed by autopsy. Filter movement greater than 9 mm was seen in 13 patients, (11%) and increase in base diameter greater than or equal to 5 mm was seen in 17 patients (14%). CT scanning showed evidence of caval penetration in only one patient (0.8%). Insertion site venous thrombosis was seen in 4/46 (8.7%) patients screened. The modified hook titanium Greenfield filter is inserted percutaneously or operatively through a sheath, eliminating concern for misplacement from premature discharge.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved regional selectivity of hepatic arterial bcnu with degradable microspheres

Starch microspheres 40 μm in diameter, which are rapidly degraded by serum amylase, have been administered through hepatic arterial catheters to five patients with primary and metastatic liver cancer to determine whether (1) arterial blood flow through the liver could be temporarily blocked, and (2) such occlusion at the level of the arteriolar capillary bed would enhance regional uptake and catabolism and decrease systemic exposure to simultaneously administered hepatic arterial bischlorethylnitrosourea (BCNU). It was possible with 10 ml of microspheres (9 × 106 microspheres/ml) injected into the hepatic artery to transiently (for 15‐30 minutes) reduce hepatic flow by 80‐100% in the five patients. When BCNU (50 mg/m2 in one minute) was given with microspheres there was a 30‐90% reduction in systemic nitrosourea exposure and in peak levels. No myelosuppression was noted and hepatic toxicity consisted of acute pain due to BCNU and 1.5‐2.0 fold transient enzyme elevations. One patient with cholangiocarcinoma showed a partial response lasting three months; three patients had stable disease and one patient with colon carcinoma had progressive disease. Thus, this pilot study suggests that concurrent intra‐arterial microspheres and BCNU may have the potential to improve selective regional drug effect with marked diminution in systemic toxicity.

Outcome Analysis of 42 Cases of Renal Angiomyolipoma

Angiomyolipomas were found in 42 kidneys in 23 female and 8 male patients at our medical center. Angiomyolipoma was diagnosed by computerized tomography (CT) alone in 55% of the cases, and by a combination of ultrasound and CT in 36%. Nine of 11 patients with bilateral angiomyolipoma had associated tuberous sclerosis. Treatment consisted of observation in 22 patients, selective arterial embolization in 6, partial nephrectomy in 6 and nephrectomy in 8. A total of 17 patients who were observed had tumors smaller than 4 cm. and 4 h had angiomyolipoma of 4 to 10 cm. With a mean followup of 3.8 years, no observation patient had subsequent renal hemorrhage and only 1 (tumor larger than 10 cm.) had radiographic progression. Despite progression, the latter patient remained asymptomatic for 18 years. Selective arterial embolization (3 tumors 4 to 10 cm. and 3 larger than 10 cm.) resulted in preservation of renal function at a mean of 1 year. All patients treated with partial nephrectomy (6 tumors 4 to 10 cm.) maintained stable renal function without recurrence during a mean 4.7-year followup. Similarly, all individuals who underwent nephrectomy (4 tumors smaller than 4 cm., 3 tumors 4 to 10 cm. and 1 tumor larger than 10 cm.) have stable renal function. We recommend renal conservation for patients with renal angiomyolipoma using a strategy of observation for small asymptomatic tumors, partial nephrectomy for moderate size tumors and selective arterial embolization of large tumors not amenable to partial nephrectomy.

Non-neoplastic congenital and acquired renal arteriovenous malformations and fistulas

Abnormal renal arteriovenous communications were documented by renal angiography in 21 patients. Included were congenital malformations, traumatic fistulas and spontaneous fistulas associated with renal arterial disease. Each type exhibited characteristic angiographic features. Overt clinical manifestations were observed in more than half the cases. Specific treatment depended upon type, location and size of the arteriovenous communication. Small, covert renal fistulas and malformations were managed conservatively. Five medium size symptomatic intrarenal arteriovenous fistulas and one malformation were successfully treated by transcatheter embolization. Large lesions, especially when associated with renal arterial disease, may be more appropriately treated by surgery.

Transhepatic Cardiac Catheterization in Children: Evaluation of Efficacy and Safety

BACKGROUND In some children with congenital heart disease, conventional venous access is unavailable for cardiac catheterization. This study investigates a novel transhepatic venous approach to cardiac catheterization in children and evaluates its efficacy and safety. METHODS AND RESULTS Percutaneous transhepatic puncture was performed using a 22-gauge Chiba needle under fluoroscopic guidance. After wire exchanges were performed, a 5F to 8F sheath was positioned in the low right atrium and cardiac catheterization was performed. On completion of the catheterization, the sheath was withdrawn and a 3-mm steel coil was placed in the parenchymal tract between the hepatic vein and liver capsule. Liver enzyme studies were obtained before and after transhepatic catheterization, and an abdominal ultrasound was performed to evaluate the liver 24 hours after the procedure. Percutaneous transhepatic cardiac catheterization was performed successfully in 17 of 18 children in whom it was attempted. Patient age was 30 +/- 8 months (mean +/- SEM; range, 1 day to 9 years), weight was 10.5 +/- 1.5 kg (3.1 to 27.5 kg), and mean right atrial pressure was 10 +/- 1 mm Hg (5 to 19 mm Hg). Time from initial needle puncture to right atrial entry was 6.2 +/- 1.2 minutes. Diagnostic catheterization was performed successfully in all 17 children, and additional interventional procedures were performed in 5 children. The total catheterization time was 2.0 +/- 0.2 hours. Serum aspartate aminotransferase increased from 57 +/- 15 to 78 +/- 8 IU/L (P = .06), but alanine aminotransferase and gamma-glutamyl transpeptidase did not change. Ultrasound was performed 24 hours after transhepatic catheterization, and no evidence was found in any patient of hemorrhage or subcapsular hematoma. CONCLUSIONS These data suggest that this novel transhepatic approach provides an effective and safe route for diagnostic and interventional cardiac catheterization in children.

Intravascular Ultrasound in the Diagnosis and Treatment of Iliac Vein Compression (May-Thurner) Syndrome

Intravascular ultrasound (IVUS) imaging and venography of the left common femoral and iliac veins were performed in 16 patients. The studies were evaluated for the anatomic cause of obstruction and how IVUS influenced endovascular management. IVUS demonstrated the cause of vessel compression in all 16 patients. Other findings, such as associated thrombus and guide wire localization within the residual vessel lumen, can modify the approach to intervention in as many as 50% of patients. IVUS is a useful adjunct in the diagnosis and endovascular management of iliac vein compression syndrome.

Somatostatin analogue (SMS 201-995) in the management of gastroenteropancreatic tumors and diarrhea syndromes

SMS 201-995 (Sandostatin) was studied using low doses (50 to 100 micrograms) administered subcutaneously every 12 hours. A single 50-micrograms dose of SMS 201-995 effectively controlled gastric acid and blood gastrin levels for 12 hours in three patients with benign gastrinomas and was useful in their perioperative management. Higher doses of the agent (500 to 800 micrograms per day) had no effect on metastases in one of two patients with metastatic gastrinoma. In the other patient, one tumor shrank but the other continued to grow after three months of treatment while serum gastrin levels did not change. Cultured metastatic tumor tissue from this patient released different forms of gastrin; growth rates varied, independent of uptake of SMS 201-995, and gastrin release increased. A neonate with nesidioblastosis maintained normal blood glucose levels while receiving SMS 201-995 therapy following a 95 percent pancreatic resection. In two elderly patients with organic hypoglycemia--one with a single benign adenoma and one with multiple adenomatosis--the somatostatin analogue did not prolong the hypoglycemia-free interval. In nine patients with carcinoid syndrome, flushing was uniformly controlled with 50 micrograms of SMS 201-995 administered every eight to 12 hours. One of the nine required exocrine pancreatic replacement. After six months of treatment, three of the nine had no change in tumor size and one had remission of symptoms and stopped treatment. In two patients with vipoma, SMS 201-995 controlled diarrhea and reduced levels of vasoactive intestinal peptide; tumor necrosis occurred in one patient. In a patient with diabetic diarrhea unresponsive to all treatments, SMS 201-995 therapy controlled the diarrhea but did not interfere with control of the diabetes.

Diagnosis and management of congenital cystic disease of the lung in children

Pulmonary sequestration, congenital adenomatoid malformation (CAM), congenital lobar overinflation (CLO), and bronchogenic cysts are four congenital lesions that may present as abnormal cystic areas within the pleural cavity in early life. They share similar clinical and embryologic characteristics, are frequently difficult to diagnose, and all require surgical treatment. From December 1974 to January 1985, 22 patients were operated upon on the Pediatric Surgical Service for congenital cystic disease of the lung. There were eight females and 14 males, ranging in age from 1 day to 18 years; 12 were under 6 months of age, and 14 were under one year. There were 7 CAMs, 5 extralobar pulmonary sequestrations, 5 intralobar pulmonary sequestrations, 3 bronchogenic cysts, and 3 cystic lobes caused by CLO. One patient had bilateral pulmonary sequestrations, intralobar on one side and extralobar on the other, with both sharing a common systemic artery arising from the infradiaphragmatic aorta. All except two asymptomatic patients presented with either progressive respiratory distress or recurrent pulmonary infections, and had cystic changes noted on chest roentgenograms. The differentiation of these congenital lesions from resolvable inflammatory cysts is important. Diagnosis was aided by selective utilization of barium contrast studies, ultrasonography, computed tomography, and arteriography. Operation consisted of resection alone of the extralobar pulmonary sequestrations and bronchogenic cysts, and total lobectomy in CAM, intralobar sequestration, and CLO. One infant with CAM died 1 day postoperatively from bilateral hypoplastic lungs. The other 21 patients are alive and well with follow-up ranging from 1 month to 9 years, with a mean of 3.5 years.(ABSTRACT TRUNCATED AT 250 WORDS)