The significance and clinical factors associated with a subcentimeter resection of colorectal liver metastases.

BACKGROUND: Prognosis after resection of colorectal liver metastases is influenced by various factors. A positive margin of resection (MOR) has been shown to adversely influence prognosis. Although a 1-cm MOR has been accepted as adequate, the data to support this guideline are sparse. METHODS: Our hepatobiliary database was queried for patients who underwent liver resection for colorectal metastases between January 1992 and July 2003. All patients were divided into three groups: MOR <.5 cm (group A), .5 to 1 cm (group B), and >1 cm (group C). Operative reports from each hepatic resection were analyzed to determine local factors that may have contributed to a subcentimeter MOR. RESULTS: A total of 112 patients (67 men and 45 women) underwent liver resection for colorectal metastases with negative margins. Fifty-three patients were in group A, 26 patients were in group B, and 33 patients were in group C. Group C demonstrated decreased local recurrence (LR; P = .003), distant recurrence (DR; P = .008), and disease-free recurrence (P = .002). A significant difference in the overall time to LR (P = .003), time to DR (P = .003), and disease-free survival (P = .002) was also demonstrated. Factors associated with a subcentimeter MOR included nonanatomical resection (P = .043), proximity to a major vessel (P = .003), and central location (P = .002). CONCLUSIONS: A <1-cm resection for colorectal liver metastases is associated with increased LR and DR, as well as decreased disease-free survival. When a nonanatomical resection is performed, a MOR >1 cm should be attempted, because an adequate margin is often underestimated. Considerations should be made for extended resections when tumors are centrally located or near major vessels.

Dynamic helical computed tomography scan accurately detects hemorrhage in patients with pelvic fracture.

BACKGROUND: The purpose of this study was to evaluate the use of dynamic helical computed tomography (CT) scan for screening patients with pelvic fractures and hemorrhage requiring angiographic embolization for control of bleeding. METHODS: Patients admitted to the trauma service with pelvic fractures were identified from the trauma registry. Data retrieval included demographics, hemodynamic instability, Injury Severity Score, blood transfusion requirement, length of stay, and mortality. CT scans obtained during the initial evaluation were reviewed for the presence of contrast extravasation and correlated with angiographic findings. Data are reported as mean +/- SEM, with P<.05 considered significant. RESULTS: Seven thousand seven hundred eighty-one patients were admitted from June 1994 to May 1999. A pelvic fracture was diagnosed in 660 (8.5%). Two hundred ninety (44.0%) dynamic helical CT scans were performed, of which 13 (4.5%) identified contrast extravasation. Nine (69%) were hemodynamically unstable and had pelvic arteriography performed. Arterial bleeding was confirmed in all and controlled by embolization. Patients with contrast extravasation had significantly greater Injury Severity Score, blood transfusion requirement and length of stay. Sensitivity, specificity, and accuracy of CT scan for identifying patients requiring embolization were 90.0%, 98.6%, and 98.3%, respectively. CONCLUSIONS: Early use of dynamic helical CT scanning in the multiply injured patient with a pelvic fracture accurately identifies the need for emergent angiographic embolization.

Zone I retroperitoneal hematoma identified by computed tomography scan as an indicator of significant abdominal injury.

OBJECTIVE: All zone I retroperitoneal hematomas (Z1RPHs) identified at laparotomy for blunt trauma traditionally require exploration. The purpose of this study was to correlate patient outcome after blunt abdominal trauma with the presence of Z1RPH diagnosed on admission computed tomography (CT) scan. METHODS: This is a retrospective review of patients with blunt trauma who were admitted to a Level 1 trauma center and who underwent CT scan during a 40-month period. All scans with a traumatic injury were reviewed to identify and grade Z1RPH as mild, moderate, or severe. Patients requiring operative treatment were compared with those who were observed. Statistical analysis was performed with Student's t test and chi-square test, with P < .05 considered significant. RESULTS: Eighty-five (15.5%) of the CT scans were positive for Z1RPH. None of the 50 patients with a mild Z1RPH had their treatment altered. Of the 29 patients with a moderate or severe Z1RPH, 8 required celiotomy. The patients requiring celiotomy had significant elevations of solid viscus score (SVS) (4.9 +/- 1.6 versus 1.8 +/- 0.3), abdominal Abbreviated Injury Scale (3.8 +/- 0.3 versus 2.6 +/- 0.3), and transfusion requirements (13 +/- 4 versus 2 +/- 1). All patients (N = 4) with an SVS >4 required operative treatment. Seventy-two percent of patients with more than 1 intra-abdominal injury required abdominal exploration. CONCLUSIONS: The presence of a moderate or severe Z1RPH and more than 1 intra-abdominal injury or an SVS >4 on admission CT scan is an important radiographic finding. This injury pattern should be considered a contraindication for nonoperative treatment of the associated solid organ injury.

Motion artifact in T2-weighted fast spin-echo images of the liver: effect on image contrast and reduction of artifact using respiratory triggering in normal volunteers.

The purpose of our study was to evaluate the effect of respiratory motion on the image contrast of T2-weighted fast spin-echo (FSE) images of the liver as well as the reduction of motion artifact using respiratory triggering of the data acquisition. We imaged the livers of 10 healthy volunteers using a fast spin-echo T2-weighted sequence. Images were obtained both without and with patient triggering. Triggered images were acquired in a segmented fashion during multiple sequential breath-holds using an echo train of 8 or 16, both with and without flow compensation (gradient moment nulling). Ratios of signal difference to noise (SD/N) of the liver and gallbladder as well as the liver and spleen were compared for all sequences. All of the triggered images showed statistically significant improvement of SD/N for the liver and gallbladder as well as for the liver and spleen when compared with the nontriggered images. Triggered images obtained with an echo train length of 8 and, with flow compensation, showed the highest SD/N ratios. In one volunteer whose liver contained multiple small cysts, the triggered images showed improved visualization of individual cysts and identified a larger number of cysts. Respiratory motion causes a significant loss of contrast on T2-weighted fast spin-echo images of the liver. This can be reduced by using a segmented data acquisition triggered by the respiratory cycle obtained during sequential breath-holds.

Acute flank pain: comparison of non-contrast-enhanced CT and intravenous urography.

PURPOSE: To compare non-contrast-enhanced computed tomography (CT) and intravenous urography (IVU) in the evaluation of patients who present with acute flank pain and in whom ureteric obstruction is suspected. MATERIALS AND METHODS: The findings at non-contrast-enhanced CT and IVU in 20 patients with acute flank pain were compared for the presence or absence of ureteric obstruction and delineation of ureteric stones. RESULTS: Twelve of the 20 patients had non-contrast-enhanced CT and IVU findings consistent with ureteric obstruction. Of these 12 patients, five had a ureteric stone that was demonstrated on both non-contrast-enhanced CT scans and IVU radiographs, six had a stone that was depicted on non-contrast-enhanced CT scans only, and in one patient a stone could not be delineated definitively on either non-contrast-enhanced CT scans or IVU radiographs. Eight patients had findings at non-contrast-enhanced CT and IVU consistent with the absence of obstruction. CONCLUSION: Non-contrast-enhanced CT is more effective than IVU in precisely identifying ureteric stones and is equally effective as IVU in the determination of the presence or absence of ureteric obstruction.

Stress fracture of the first rib from serratus anterior tension: an unusual mechanism of injury.

Fracture of the first rib usually results from high-impact, direct trauma. Stress fractures are less common and are associated with minimal morbidity. The case of a patient with a stress fracture resulting from the use of an exercise machine is reported. Previous reports have attributed stress and fatigue fractures of the first rib to the forces exerted by the scalene muscles. A new pathophysiologic mechanism involving the serratus anterior muscle is introduced and is supported by T2 relaxation times from magnetic resonance imaging. Stress and fatigue fractures of the first rib have minimal complications. An aggressive diagnostic evaluation of first rib fractures occurring by this mechanism is not warranted.