Stephen G. Gerzof

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.

Percutaneous Catheter Drainage of Abdominal Abscesses

We used computed tomography (CT) and ultrasonography for detection and localization of intra-abdominal abscesses. On the basis of these images, safe routes for diagnostic aspiration and percutaneous drainage were planned. Over these routes indwelling catheters were inserted to provide immediate decompression, evacuation, and continuous drainage until the abscess resolved. All patients received concomitant intravenous antibiotics. The treatment was used for 71 abscesses in 67 patients. Sixty-one abscesses (86 per cent) were satisfactorily drained. There were 11 complications (15 per cent). Six deaths were attributable to sepsis, three of which (4 per cent) were related to inadequate drainage. There was one recurrence (1 per cent) during a follow-up period ranging from one month to five years (means, 22.3 months). The mean duration of treatment was 20.2 days (range, five to 120 days). We conclude that percutaneous drainage is an effective method for treatment of abdominal abscesses and is indicated when sectional imaging demonstrates an accessible unilocular lesion.

CT-guided aspiration of suspected pancreatic infection

SummaryWe 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, andStaphylococcus 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=0.01). 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 infectoon 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.

Treatment of abdominal abscesses: comparative evaluation of operative drainage versus percutaneous catheter drainage guided by computed tomography or ultrasound.

Computed tomography and, to a lesser extent, ultrasonography provide detailed anatomic localization of intraabdominal abscesses that permit precise percutaneous placement of catheters large enough to effect drainage. Using routes similar to surgical approaches, the authors have used this technique as definitive therapy for intra-abdominal abscesses. To assess its efficacy, the results in the 27 patients treated percutaneously over the last five years have been compared with the results in the 43 patients treated by operative intervention over the past ten years. In the percutaneous group, complications (4%), inadequate drainage (11%), and duration of drainage (17 days) were less than in the operative group (16%, 21% and 29 days respectively). These results indicate that percutaneous drainage is at least as efficacious as operative drainage and avoids the risks of a major operative procedure

Prevalence of normal serum amylase levels in patients with acute alcoholic pancreatitis

Acute alcoholic pancreatitis is uncommonly diagnosed when the serum amylase level is normal. We defined acute alcoholic pancreatitis as a clinical syndrome in which hyperamylasemia was not a necessary component and sought support for the diagnosis by ultrasonography and computed tomography of the pancreas. In 68 episodes of acute alcoholic pancreatitis identified in a one-year period, the serum amylase level was normal at the time of hospital admission in 32%. In 40 episodes, we performed ultrasonography and computed tomography within 48 hr of admission. The diagnosis was supported by ultrasonography in 43%, by computed tomography in 68%. Ultrasonography and computed tomography supported the diagnosis as frequently in patients with normal serum amylase levels as in patients with hyperamylasemia. We conclude that patients with acute alcoholic pancreatitis frequently have normal serum amylase levels. The widespread clinical practice of relying solely on hyperamylasemia to establish the diagnosis of acute alocholic pancreatitis is unjustified and should be abandoned.

Bacteriologic status of necrotic tissue in necrotizing pancreatitis

To confirm the accuracy of guided percutaneous aspiration (GPA) in distinguishing sterile from infected pancreatic necrosis, we have performed Brown-Brenn tissue Gram stains on pancreatic and peripancreatic necrotic tissue removed operatively in 15 patients. In eight patients judged to have sterile necrosis on the basis of negative cultures of pancreatic exudate obtained first preoperatively (by GPA) and then intraoperatively, necrotic tissue debrided at surgery was also free of bacteria. In seven patients judged to have infected necrosis on the basis of positive cultures of pancreatic exudate obtained fist preoperatively (by GPA) and then intraoperatively, necrotic tissue debrided at surgery harbored a considerable number of bacteria. We conclude that GPA targeted to areas of necrosis accurately distinguishes infected necrosis from sterile necrosis, and in infected necrosis, the solid necrotic tissue as well as the fluid component contains bacteria. We therefore believe that infected necrosis is not likely to be eradicated by catheter drainage and should be treated by surgical debridement.

Portal architecture: a differential guide to fatty infiltration of the liver on computed tomography.

Fatty infiltration of the liver, like fatty lesions elsewhere in the body, typically appears as low-density areas on computed tomography (CT). Fatty infiltration of the liver should be considered in the differential diagnosis of homogeneous lowdensity hepatic lesions regardless of distribution or size. As a physiologic rather than anatomic change, fatty infiltration of the liver characteristically leaves the portal venous architecture unaltered. Although fatty infiltration of the liver typically presents with complete or near complete involvement, other unusual patterns may be encountered. In these atypical cases, recognition of the normal portal structures on CT aids in correct diagnosis.

Mediastinal pancreatic pseudocyst.

SummaryAmong previous cases of mediastinal pseudocyst requiring surgical decompression, all but one had been found at surgery to occupy a position both in the mediastinum and in the upper abdomen. In the present case, although preoperative ultrasound and CT scans suggested that the pseudocyst was straddling the diaphragm, an abdominal portion could not be found at surgery, and the pseudocyst was drained successfully through the diaphragm by a Roux-en-Y loop of jejunum. Because ultrasound and CT scan may not be able to determine the precise relationship of a mediastinal pseudocyst to the diaphragm and the availability of the lower portion of the pseudocyst for surgical decompression, an endoscopic retrograde cholangiopancreatography is strongly recommended as part of the preoperative evaluation.

Treatment of chronic pancreatitic pleural effusion by percutaneous catheter drainage of abdominal pseudocyst

A 53-year-old man entered the hospital with a large, right chronic pancreatitic pleural effusion. Computed tomographic examination of the abdomen and chest demonstrated a pancreatic pseudocyst that had extended into the mediastinum. After conventional closed-chest tube thoracotomy drainage failed to empty the pleural space, percutaneous abdominal pseudocyst drainage was instituted using computed tomographic guidance. The pleural effusion cleared promptly, and the pancreatic pseudocyst resolved gradually over seven weeks. Following termination of pseudocyst drainage, the patient has remained well for over two years with no recurrence of pancreatitis, pseudocyst, or pleural effusion. In contrast, three earlier patients with a chronic pancreatitic effusion managed conventionally had a complicated hospital course and required surgical intervention; two had recurrent pancreatitis following hospital discharge. Percutaneous catheter placement was unsuccessful in one of these three and, in retrospect, was infeasible in the other two. It is recommended that thoracoabdominal computed tomography be performed in all patients with a chronic pancreatitic pleural effusion, and that percutaneous abdominal catheter drainage be attempted in all patients with an accessible pancreatic or mediastinal pseudocyst. Such treatment may relieve respiratory insufficiency, minimize the risk of empyema or fibrothorax, and may promote pseudocyst closure without the need for surgery.

Percutaneous drainage of renal and perinephric abscess

Computed tomography and ultrasonography are effective methods for diagnosis and localization of renal and perinephric abscesses. In patients with clinical suspicion of sepsis, diagnostic needle aspiration of these lesions can be safely performed extraperitoneally by using sectional imaging for guidance. When an abscess is confirmed, small catheters can be introduced percutaneously via the diagnostic aspiration route to provide immediate decompression as well as continuous and definitive drainage without need for surgery. In 8 cases so treated, there were no major complications, deaths, or recurrences. These results, obtainable without the risks of surgery, indicate that patients with renal or perinephric abscesses should be offered a trial of percutaneous drainage as a definitive method of therapy. Those cases not amenable to percutaneous drainage, or those in which the procedure has failed, can then be drained surgically. Percutaneous abscess drainage is widely applicable because it can be performed in any uroradiologic facility with access to sectional imaging.