Obstructive jaundice and renal masses.

An 82-year-old patient with obstructive jaundice secondary to simple renal cyst also suffered pain and vomiting from partial duodenal obstruction. The symptoms were relieved by aspiration of 1,750 ml of fluid. This reaccumulated over a five-year period when aspiration again relieved his symptoms, which then only consisted of epigastric fullness. Review of the literature shows jaundice to be an extremely rare symptom of renal cyst.

Clinical features and natural history of central cavitary necrosis.

Central cavitary necrosis (CCN) is an unusual complication of acute pancreatitis in which the necrosis is confined almost entirely to the pancreatic parenchyma and there is little if any extrapancreatic necrosis. In our experience with 10 patients with CCN, clinical features suggested that the episodes of acute pancreatitis were initially severe, with high Ranson scores (mean, 4.2; range, 1-6), development of systemic complications, computed tomography (CT) grade of D or E by the Balthazar-Ranson scoring system, need for intensive care unit admission in 8 of 10 patients, and mean length of hospitalization of 56 days (range, 28-153 days). However, the incidence of infection was low (20%) and mortality was also low (10%). Factors that help explain a favorable prognosis were low APACHE-II scores at admission and at 48 h, absence of shock, paucity of extrapancreatic necrosis, and rapid resolution of clinical toxicity prior to the diagnosis of CCN by CT scan at a mean of 19.8 days (range, 9-63 days) after the onset of symptoms. Surgical debridement is indicated for complications such as secondary infection and ongoing pain. In the absence of complications, an attempt should be made to treat CCN medically.

Proximal jejunal intussusception associated with a long tube.

An intussusception of the small intestine in association with a long tube usually occurs in the vicinity of the mercury-filled bag and can be visualized radiographically by instilling barium directly into the tube. On rare occasions, an intussusception develops in the proximal jejunum and is difficult to recognize. We report the fifth and sixth cases of a proximal jejunal intussusception with a long tube in situ and outline a clinical approach that facilitates a prompt, accurate diagnosis. A proximal jejunal intussusception should be suspected if copious bilious vomiting and abdominal pain occur following intubation of the small intestine with a long tube.

Delayed common bile duct obstruction in acute pancreatitis.

Common bile duct obstruction during acute pancreatitis usually occurs in the early symptomatic phase of the illness, involves only the distal portion of the common bile duct, and subsides with clinical improvement. We present two cases of persistent common bile duct obstruction that developed 2-3 months after complete clinical subsidence of the initial episode of severe acute pancreatitis and involved a long segment of the common bile duct. After surgical decompression, there was no recurrence of common bile duct obstruction or pancreatitis.

Prognostic factors in sterile pancreatic necrosis.

Although the overall mortality in sterile pancreatic necrosis is low, patients who experience systemic complications may have a higher mortality. To study the impact of systemic complications and other factors on survival, possible prognostic factors were evaluated among 26 patients who experienced at least one systemic complication. Mortality was 38%. Factors that correlated with a fatal outcome were high Ranson's scores during the first 48 hours (P = 0.01), high APACHE-II scores at admission (P = 0.04) and at 48 hours (P = 0.03), shock (P < 0.001), renal insufficiency (P < 0.05), multiple systemic complications (P < 0.001), and high body mass index (P = 0.01). Most systemic complications occurred during the first 2 weeks of illness. Logistic regression analysis showed that shock was the best predictor of a fatal outcome. Patients with favorable prognostic factors survived whether treated medically or surgically, whereas those with unfavorable factors had a fatal outcome whether treated medically or surgically. It is concluded that patients with severe sterile necrosis have a high mortality rate and that shock and other prognostic factors identify which patients are most likely to have a fatal outcome.

Combination balloon-ultrasound imaging catheter for percutaneous transluminal angioplasty. Validation of imaging, analysis of recoil, and identification of plaque fracture.

BACKGROUND: We investigated the hypothesis that an ultrasound transducer positioned within an angioplasty balloon could be used to perform quantitative assessment of arterial dimensions before and after percutaneous transluminal angioplasty (PTA) and to identify certain mechanical alterations consequent to PTA, including vascular wall recoil and the initiation of plaque fractures. METHODS AND RESULTS: A combination balloon-ultrasound imaging catheter (BUIC) that houses a 20-MHz ultrasound transducer within and halfway between the proximal and distal ends of an angioplasty balloon was used to perform PTA in 10 patients with peripheral vascular disease. Each PTA site was also evaluated before and after PTA by standard (nonballoon) intravascular ultrasound (IVUS) technique. In eight patients in whom satisfactory images were recorded with the BUIC before PTA, luminal cross-sectional area (XSA) of stenotic sites (0.10 +/- 0.01 cm2) did not differ significantly from measurements of XSA by IVUS (0.09 +/- 0.01 cm2, p = NS). Likewise, minimum luminal diameter (Dmin) measured by BUIC (0.34 +/- 0.02 cm) was similar to that measured by IVUS (0.33 +/- 0.01 cm, p = NS). In nine patients in whom satisfactory images were recorded with the BUIC after PTA, XSA measured by BUIC (0.29 +/- 0.03 cm2) did not differ significantly from XSA measured by IVUS (0.30 +/- 0.03 cm2, p = NS). Dmin measured by BUIC after PTA (0.57 +/- 0.02 cm) was also similar to Dmin measured by IVUS (0.57 +/- 0.03 cm, p = NS). After PTA, XSA and Dmin measured immediately after deflation were significantly less than balloon XSA and diameter at full inflation, indicating significant elastic recoil of the dilated site. For the nine patients in whom post-PTA images were satisfactory for quantitative analysis, including four patients in whom recoil was 39%, 46%, 50%, and 61%, percent recoil measured 28.6 +/- 7.2%. Finally, plaque fractures were identified on-line in six of 10 patients (60%); in each case, initiation of plaque fracture was observed at inflation pressures of 2 atm or less. CONCLUSIONS: The results of this preliminary human investigation indicate that an ultrasound transducer positioned within an angioplasty balloon can be used to perform quantitative and qualitative analyses of lumen-plaque-wall alterations immediately preceding, during, and immediately after PTA in patients with peripheral vascular disease.

CT-guided aspiration of suspected pancreatic infection: bacteriology and clinical outcome.

We have performed CT-guided percutaneous needle aspiration in 104 patients with severe pancreatitis strongly suspected of harboring pancreatic infection on the basis of systemic toxicity and CT findings (Balthazar CT grade D or E). Of these 104 patients, 51 (49%) were documented with pancreatic infection. Gram stain was positive in 54 of 58 infected aspirates, and culture was positive in all 58. Klebsiella, Escherichia coli, and Staphylococcus aureus were the most frequent organisms. Eighty-six percent of infected processes contained only one organism. Overall, pancreatic infection was documented by GPA within the first 2 wk in approx one-half of patients. There were no complications. The overall rate of infection decreased from 60 (1980-1987) to 34% (1988-1995) (p = 0.011). This change was caused by a reduction in the rate of infected necrosis from 67 to 32% (p = 0.015). The overall mortality rate remained at 20%. The mortality of sterile pancreatitis was not different from infected pancreatitis (p = 0.14). We conclude that GPA is a safe, accurate method of diagnosis of pancreatic infection. The rate of pancreatic infection appears to be decreasing. The overall mortality of severe pancreatitis among patients suspected of harboring pancreatic infection has remained unchanged because of the high mortality associated with both infected necrosis and severe sterile necrosis.

Human coronary and peripheral arteries: on-line three-dimensional reconstruction from two-dimensional intravascular US scans. Work in progress.

To explore the feasibility of computer-based, on-line three-dimensional reconstruction, timed manual withdrawal (pullback) recordings were obtained with two-dimensional intravascular ultrasound (US) in 42 patients who underwent percutaneous revascularization. Three-dimensional processing was performed with commercial software that stacked serially obtained intravascular US scans and created a new set of data points in four steps: interpolation, segmentation, boundary encoding, and surface rendering. In all 42 patients, satisfactory on-line three-dimensional reconstruction was accomplished. In the first three patients, 70-90 seconds was required for three-dimensional processing, and display was limited to the sagittal format. In the next six patients, a sagittal display was rendered in 45-60 seconds, and on-line reconstruction in the cylindrical format was achieved within 30 additional seconds. In the last 33 patients, an unlimited number of sagittal views could be produced in 30-40 seconds, the extra time required for cylindrical display was shortened to 15-20 seconds, and a luminal cast display was added to the on-line menu.

Three-dimensional reconstruction of human coronary and peripheral arteries from images recorded during two-dimensional intravascular ultrasound examination.

BACKGROUND: Intravascular ultrasound provides high-resolution images of vascular lumen, plaque, and subjacent structures in the vessel wall; current instrumentation, however, limits the operator to viewing a single, tomographic, two-dimensional image at any one time. Comparative analysis of serial two-dimensional images requires repeated review of the video playback recorded during the two-dimensional examination, followed by a "mind's eye" type of imagined reconstruction. METHODS AND RESULTS: Computer-based, automated three-dimensional reconstruction was used to generate a tangible format with which to assess and compare a "stacked" series of two-dimensional images. Three-dimensional representations were prepared from sequential images obtained during intravascular ultrasound examination in 52 patients, 50 of whom were studied before and/or after percutaneous revascularization. Conventional two-dimensional ultrasound images were acquired by means of a systematic, timed pullback of the ultrasound catheter through the respective vascular segments. Images were then assembled in automated fashion to create a three-dimensional depiction of the vessel lumen and wall. Computer-enhanced three-dimensional reconstructions were generated in both sagittal and cylindrical formats. The sagittal format resulted in a longitudinal profile similar to that obtained during angiographic examination; in contrast to angiography, however, the sagittal reconstruction offered 360 degrees of limitless orthogonal views of the plaque and arterial wall as well as the vascular lumen. The cylindrical format yielded a composite view of a given vascular segment, and a hemisected version of the cylindrical reconstruction enabled en face inspection of the reconstructed luminal surface. Sagittal reconstructions facilitated analysis of dissections and plaque fractures resulting from percutaneous revascularization, and the hemisected cylindrical reconstructions enhanced analysis of endovascular prostheses. CONCLUSIONS: This preliminary experience demonstrates that computer-based three-dimensional reconstruction may further augment the use of intravascular ultrasound in assessing vascular pathology and guiding interventional therapy.

Percutaneous intravascular US as adjunct to catheter-based interventions: preliminary experience in patients with peripheral vascular disease.

Catheter-based ultrasound (US) transducers may be introduced into the vascular system to record high-resolution images of the vessel wall and lumen. The potential advantages and existing liabilities of percutaneous intravascular US as an adjunct to transluminal vascular recanalization were investigated. A 6.6-F braided, polyethylene catheter enclosing a rotary drive shaft with a single-element, 20-MHz transducer at the distal tip was used in 17 patients undergoing percutaneous transluminal (balloon) angioplasty (PTA) alone (10 patients), PTA with implantation of an endovascular stent (two patients), atherectomy alone (two patients), or laser angioplasty with PTA and/or atherectomy (three patients). The arteries treated and examined included the common iliac in five patients, the external iliac in two, the superficial femoral in nine, and a vein graft-arterial anastomosis in one. In 14 cases PTA was employed as sole or adjunctive therapy; plaque cracks were clearly delineated with intravascular US in all 14 (100%) and dissections were observed in 11 (78%). Plaque-arterial wall disruption was less prominent in the arteries treated with mechanical atherectomy. The results of laser angioplasty reflected the adjunctive modality employed. After stent implantation, serial intravascular US documented effacement of PTA-induced plaque cracks and/or dissections. Intravascular US also aided in the quantitative assessment of luminal cross-sectional areas after the procedures (19.0-51.8 mm2). The observations recorded in this preliminary group of 17 patients illustrate the potential utility of intravascular US as an adjunct to conventional angiography in patients undergoing percutaneous revascularization.

In vivo assessment of vascular pathology resulting from laser irradiation. Analysis of 23 patients studied by directional atherectomy immediately after laser angioplasty.

BACKGROUND: The pathological consequences of cardiovascular laser irradiation have been studied extensively in vitro. Previous in vivo studies of laser-induced injury have included analyses of acute and/or chronic findings in experimental animals. Little information, however, is available regarding the acute effects of laser irradiation of human vascular tissues in vivo. METHODS AND RESULTS: To determine the acute pathology resulting from laser irradiation of human vascular tissue in vivo, specimens retrieved from 23 patients by directional atherectomy immediately after laser angioplasty (19 peripheral and four coronary) were examined by light microscopy. Of the 23 patients, three (13.0%) were treated with a metal-capped ("hot-tip") fiber coupled to a continuous-wave neodymium:yttrium-aluminum-garnet (Nd:YAG) laser using up to 18 W power and 18-305 seconds of cumulative exposure time; in all three patients (100%), thermal injury, including frank charring several cell layers thick, was seen along the luminal borders of the atherectomy specimen. In eight of the 23 patients (34.5%), laser angioplasty was performed using a 250-microseconds holmium:YAG laser at fluences up to 2,300 mJ/mm2, a repetition rate of 5 Hz, and 25-200 seconds of cumulative exposure; in seven of eight patients (85.5%), the atherectomy specimen showed signs of vacuolar injury consisting of central and satellite Alcian-blue-negative vacuoles. In two patients (25.0%), there was a "smudged" or "shredded" edge, whereas in one patient, frank signs of thermal injury were observed. Finally, in 12 of the 23 patients (52.2%), laser angioplasty was performed using a 120-nsec excimer laser at fluences up to 60 mJ/mm2, a repetition rate of 25 Hz, and a cumulative exposure time of 21-315 seconds. Pathological findings among these 12 patients were limited to nine patients (75%) in whom a weakly basophilic, smudged, and/or shredded appearance approximately one cell layer thick was observed along the luminal border of the atherectomy specimen and two patients (16.7%) with small foci of vacuolar injury. None of the atherectomy specimens retrieved after excimer laser angioplasty disclosed signs of thermal injury. CONCLUSIONS: These findings document that acute pathological alterations resulting from in vivo laser angioplasty are variable, depending on the laser source used, and are similar to that predicted by experimental studies performed previously in vitro. The prognostic implications of these varying pathological features remain to be clarified.

Early diagnosis of pancreatic infection by computed tomography-guided aspiration.

We performed 92 computed tomography-guided percutaneous needle aspirations of pancreatic inflammatory masses in 60 patients suspected of harboring pancreatic infection. Thirty-six patients (60%) were found by Gram stain and culture to have a total of 41 separate episodes of pancreatic infection. Among 42 aspirates judged to be infected by computed tomography-guided aspiration, all but one were confirmed by surgery or indwelling catheter drainage. Among 50 aspirates judged to be sterile, no subsequent evidence of infection was found. All patients tolerated the procedure well and no complications were noted. As a result of this technique, we observed that pancreatic infection occurs earlier than has been previously appreciated (within 14 days of the onset of pancreatitis in 20 of the 36 patients) and that infection may recur during prolonged bouts of pancreatitis. We conclude that guided aspiration is a safe, accurate method for identifying infection of the pancreas at an early stage.