Biomedical subjects
Publications and source records attributed to Allen J Cohen.
Superior mesenteric artery (SMA) syndrome is a rare cause of intestinal obstruction involving the duodenum. Diagnosis is based on clinical suspicion with radiologic confirmation. We report an unusual presentation of the SMA syndrome involving both the duodenum and jejunum initially not recognized on contrast-enhanced CT. This case demonstrates the judicious use of multiple modalities in evaluating for this syndrome.
Segmental infarction of the omentum and epiploic appendages presents with acute abdominal findings that may be confused with a surgical illness. Computed tomography, however, demonstrates a consistent and well-recognized pattern that allows safe, nonoperative treatment. Infarction of omental or mesenteric fat may present clinically as localized peritonitis, mimicking appendicitis, diverticulitis, or cholecystitis. Spontaneous recovery without operation is to be expected if an accurate diagnosis is established. We describe the diagnosis, treatment, and outcome of 15 patients who had infarction of the greater omentum (eight) and epiploic appendage (seven) and presented with localized abdominal pain and tenderness, with six demonstrating regional peritonitis and fever. All underwent CT imaging during their initial evaluation, and 12 of the 15 patients were diagnosed with focal omental or mesenteric fat infarction radiographically and managed nonoperatively. Three patients who had characteristic CT findings nevertheless underwent operation. All patients had complete resolution of their abdominal pain regardless of treatment. The clinical presentation of infarction of the omental or epiploic appendages may be difficult to differentiate from surgical causes of acute abdominal pain. The characteristic findings on computed tomography are diagnostic and allow safe, conservative management in the majority of patients.
Central venous catheters (CVCs) are used for both emergent and long-term vascular access for the infusion of numerous therapeutic agents such as chemotherapy, parenteral nutrition, antibiotics, and analgesics, as well as for temporary hemodialysis or hemoperfusion. Current standard of care dictates that CVC insertion should be followed by an immediate chest radiograph to confirm appropriate position. Radiographic confirmation of central venous line placement is important because it is not possible to determine CVC tip position clinically. Although many catheter tips can be localized on the standard frontal radiograph, there are occasions when a second radiograph is necessary to localize the position of the CVC tip accurately. We hypothesized that a right posterior obligue chest radiograph would more consistently enable the catheter tip to be seen as it reduces the superimposition of mediastinal structures. One hundred chest radiographs taken in an anteroposterior (AP) projection and 100 chest radiographs taken in a right posterior oblique (RPO) projection after a peripherally inserted central catheter (PICC) line placement at UCI Medical Center from June 2000 to November 2002 were read by two radiologists. Forty-one percent of AP readings were discrepant and 4% had the annotation "difficult to identify the position of the tip" although the identification of tip position was similar. Fifty-five percent of AP readings were in agreement with no note of any difficulty. Eighteen percent of RPO readings were discrepant and 2% had the annotation "difficult to identify the position of the tip" although the identification of tip position was similar. Eighty percent of RPO readings were in agreement with no note of any difficulty.
Venous air embolism (VAE) is a known complication of venous access procedures such as contrast-enhanced computed tomography (CECT). Although a massive VAE can be fatal, most iatrogenic VAE cases during CECT involve a few milliliters of air and are asymptomatic. We report two cases of massive and nonfatal VAE during CECT. Both cases involve the inadvertent injection of air instead of contrast by power injectors during the contrast phase. In both cases, the patients were stable and survived the event without permanent sequelae. We also discuss the pathophysiology, treatment, and prevention of VAE, especially during CECT.
Traumatic abdominal wall hernia (TAWH) can occur after blunt trauma and can be classified into low- or high-energy injuries. Low energy injuries occur after impact on a small blunt object. High-energy injuries are sustained during motor vehicle accidents or automobile versus pedestrian accidents. We present six cases of high-energy TAWH cases that were treated at our trauma center. All patients presented with varying degrees of abdominal tenderness with either abdominal skin ecchymosis or abrasions, which made physical examination difficult. CT scan confirmed the hernia in each patient. All six patients had associated injuries that required open repair. The abdominal wall defects were repaired primarily. Three patients (50%) in our series developed a postoperative wound infection or abscess. Review of the literature on low-energy TAWH shows no associated abdominal injuries. In conclusion distinction between low- and high-energy injury is imperative in the management of TAWH. Hernias following low-energy injuries can be repaired after local exploration through an incision overlying the defect. TAWHs following high-energy trauma should undergo exploratory laparotomy through a midline incision. The defect should be repaired primarily and prosthetics avoided because of the high incidence of postoperative infection.