Microvascular changes following four-hour single arteriole occlusion.

BACKGROUND: Free tissue transplantations are lengthy procedures that result in prolong tissue ischemia. Restoral of blood flow is essential for free flap recovery; however, upon reperfusion tissue that is viable may continue to be nonperfused. To further elucidate this pathophysiology skeletal muscle microcirculation was investigated during reperfusion following 4-hour single arteriole occlusion. MATERIALS AND METHODS: A blunt micropipette probe was use to compress a single arteriole in the unanesthetized hamster (N = 20) dorsal skinfold chamber. Arteriole (n = 20), capillary (n = 97), and postcapillary venule (n = 16) diameters and blood flow were analyzed at 0, 30, 60, 120, 240 min and 24 hours of reperfusion after 4 hour occlusion. RESULTS: Feeding arcade arterioles exhibited a brief (<10 min) vasoconstriction [0.31 ± 0.26 (mean ± SE) of baseline] upon reperfusion followed by a maximum vasodilation at 120 min (1.3 ± 0.10: P < 0.05). Vasodilation was observed in transverse arterioles (A3) (1.8 ± 0.20: P < 0.05). Correspondingly, all arteriole and venule flow was increased by 120 min (P < 0.05) of reperfusion. There was a transient decrease in the number of flowing capillaries at 0 and 30 min reperfusion (0.73 ± 0.09 and 0.84 ± 0.06: P < 0.05, respectively). CONCLUSIONS: At the onset of reperfusion heterogeneous arteriole flow and transient decrease in flowing capillaries was observed; however, return of flow in all capillaries and an eventual hyperemic response in all arterioles suggests the reversible nature of this response. Single arteriole occlusion may allow for a more controlled and detailed microcirculatory analysis during ischemia-reperfusion.

Early laparoscopic cholecystectomy for mild gallstone pancreatitis: time for a paradigm shift.

HYPOTHESIS Patients with mild gallstone pancreatitis may undergo an early laparoscopic cholecystectomy (LC) within 48 hours of hospital admission without awaiting the normalization of pancreatic and liver enzyme levels. This may decrease the hospital stay without increasing morbidity or mortality and may minimize the unnecessary use of endoscopic retrograde cholangiopancreatography. DESIGN A retrospective review. SETTING Two university-affiliated urban medical centers. PATIENTS A total of 303 patients with mild gallstone pancreatitis, of whom 117 underwent an early LC and 186 underwent a delayed LC. MAIN OUTCOME MEASURES Hospital length of stay, morbidity and mortality rates, and the use of endoscopic retrograde cholangiopancreatography. RESULTS Similar hospital admission variables were observed in the early and delayed LC groups, although the delayed group was older (P = .006). The median hospital length of stay was significantly less for the early group than for the delayed group (3 vs 6 days; P < .001). There were no patients who died, and the complication rates were similar for both groups. However, the patients who underwent an early LC were less likely than patients who underwent a delayed LC to undergo endoscopic retrograde cholangiopancreatography (P = .02). CONCLUSIONS An early LC may be safely performed for patients with mild gallstone pancreatitis, without concern for increased morbidity and mortality, resulting in shortened hospital stays and a decrease in the use of endoscopic retrograde cholangiopancreatography. The practice of delaying an LC until normalization of laboratory values appears to be unnecessary.

Analysis of exhaled volatile compounds following acute superior mesenteric artery occlusion in a pilot rat study.

BACKGROUND: Prompt diagnosis and treatment of acute mesenteric ischemia (AMI) requires a high index of suspicion for timely management. Poor clinical outcomes and delays in surgical treatment are demonstrated even in modern clinical series. Recognition of exhaled volatile organic compounds (VOCs) specific to AMI may facilitate early detection and diagnosis and improve patient outcomes. METHODS: Adult Wistar rats (n = 5) were intubated and anesthetized, and control tracheostomy breath samples were collected using Tedlar gas sample bags. Intestinal ischemia was induced by placing an occlusive clip across the superior mesenteric artery, and breath samples were collected after 1 hour of intestinal ischemia and after 15 minutes of intestinal reperfusion. Gas chromatography was used to identify and measure levels of VOCs obtained, and measured retention indices were compared with known values in the Kovats retention index database. RESULTS: Multiple retention indices (n = 41) were noted on gas chromatography, representing a variety of VOCs detected. Z,Z-farnesol (C15H26O), an isoprenoid, was the only compound detected that was undetectable during the control phase (median = 0 cts/sec) but which significantly elevated during the ischemic (median = 34 cts/sec, range = 25-37) and reperfusion (median = 148 cts/sec, range = 42-246) phases. Three other isoprenoid compounds (E,E-alpha-farnesene, germacrene A, and Z,Z-4,6,8-megastigmatriene) were also detected in all five animals, but their levels did not differ significantly between control, ischemic, and reperfusion phases. CONCLUSIONS: This pilot study demonstrates the feasibility of analyzing exhaled VOCs using a novel rat model for AMI. These findings may be useful for the development and identification of similar assays for the rapid diagnosis of AMI.

Why do breast cancer mortality rates vary across states?

In 2001 approximately 40,000 deaths from breast cancer will occur in the United States. Although some estimates suggest possible state-to-state variations in breast cancer mortality rates the reasons for such differences remain unknown. Our objective was to confirm whether breast cancer mortality rates are significantly different by state and to identify predictors for such variation. Administrative data from the National Center for Health Statistics (NCHS) report were used to determine statewide death rates. Analyses were similarly performed with the Surveillance, Epidemiology, and End Results (SEER) cancer database to determine predictors of high versus low mortality rates. State-level variation in breast cancer mortality rates was demonstrated in the NCHS database. A subsequent analysis of high versus low mortality states in the SEER cancer registry demonstrates that stage at presentation was a significant predictor of mortality, as "high" mortality states had more patients presenting with later-stage disease. We conclude that variations in the breast cancer mortality rates exist between states. A nearly 50 per cent increase is observed between the states with the highest and lowest mortality rates. Adjusted analyses demonstrate that stage at presentation is a more important predictor of mortality variation than treatment differences. As such breast cancer mortality rates may be best improved by targeting screening and access-to-care issues rather than treatment.

Effect of intraoperative cholangiography during cholecystectomy on outcome after gallstone pancreatitis.

Acute gallstone pancreatitis has traditionally been managed by early cholecystectomy with intraoperative cholangiography (IOC). To evaluate the effect of IOC on patient outcome, we analyzed all patients operated on for acute gallstone pancreatitis at our institution over a 3-year period. A total of 200 patients (37 open, 163 laparoscopic) were evaluated. Nineteen of 34 patients who underwent preoperative endoscopic retrograde cholangiopancreatography (ERCP) were found to have common bile duct (CBD) stones. The 59 patients who underwent cholecystectomy with IOC had significantly longer operative times compared to the 141 patients who underwent cholecystectomy alone (167 vs. 105 minutes for open [P = 0.008] and 89 vs. 68 minutes for laparoscopic [P < 0.0001] operations). Of the 59 patients who underwent IOC, only nine (15%) had abnormal cholangiograms, and CBD exploration in seven revealed stones in four patients, edematous ampullae in two, and no abnormality in one. Six of eight patients (5 IOC, 3 no IOC) who required immediate postoperative ERCP were noted to have CBD stones. Patients who underwent IOC had significantly longer postoperative hospital stays (3.8 vs. 2.0 days [P = 0.007]). The incidence of retained CBD stones following surgery was similar (5.1% IOC, 2.8% no IOC). Although 7 of 122 patients who underwent laparoscopic cholecystectomy without IOC were readmitted, only one was found on ERCP to have a retained CBD stone. Age, sex, preoperative days, procedure type, and biliary-pancreatic complications after discharge did not differ significantly between patients with and without IOC. We conclude that IOC in patients operated on for acute gallstone pancreatitis results in a longer operative time and a prolonged postoperative course, but has no effect on the incidence of retained CBD stones.

Management of carotid body paragangliomas and review of a 30-year experience.

Carotid body tumors are rare neoplasms and must be considered in the evaluation of all lateral neck masses; early surgical removal has been recommended. In this study, the medical records of 29 patients with 34 carotid body paragangliomas who were treated at our institution between 1971 and 2001 were retrospectively reviewed. An overview is provided of this lesion, including diagnosis, classification, metastatic potential, possible secretory function, operative techniques, and nonsurgical methods of management. Carotid body tumors may be familial and are more often bilateral in these instances; five patients (17%) had bilateral tumors in this series. The criterion for malignancy is demonstrated by metastatic tumor in lymph nodes or distant organs. Three patients (10%) had malignant tumors, one with hepatic metastases. One patient (3%) in our series exhibited abnormal serotonin production. Vascular reconstruction was necessary in eight cases (28%). No stroke occurred, however, two arterial thromboses (7%), five permanent cranial nerve deficits (17%), and one death (3%) from massive pulmonary embolism were seen. Our experience demonstrates that early operative management is warranted to avoid the possibility of eventual metastasis and progressive local invasion to the point of inoperability.

Human cytokine levels in nonperforated versus perforated appendicitis: molecular serum markers for extent of disease?

Appendicitis is a common surgical problem that is associated with a systemic inflammatory response. Previous studies have shown that cytokines are activated early in acute inflammation and sepsis and may serve as indicators of clinical severity. In this study we examined the role of cytokines as serum markers to distinguish nonperforated versus perforated appendicitis. Patients with the presumptive diagnosis of appendicitis had serum drawn preoperatively. Only patients (n = 59) with an intraoperative diagnosis of nonperforated (n = 34) and perforated (n = 25) appendicitis had serum drawn 12 hours postoperatively. Diagnosis was later confirmed by pathologic examination. The serum specimens were batch analyzed using enzyme-linked immunosorbent assays specific for interleukin (IL)-1beta, IL-2, IL-6, IL-8, and IL-10. Serum from normal healthy subjects served as control specimens (n = 9). Patients in the nonperforated and perforated groups were similar with regard to age, gender, race, white blood cell count, and fever. All cytokine levels including preoperative, postoperative, nonperforated, and perforated were higher in patients with appendicitis as compared with controls. IL-1beta, IL-2, and IL-10 levels were not different between groups with appendicitis. Preoperative serum levels of IL-6 (P = 0.036) and IL-8 (P = 0.047) were higher in patients with perforated versus nonperforated appendicitis. In addition postoperative serum levels of IL-6 (P = 0.0001) remained higher in the perforated group versus the nonperforated group. Serum levels of IL-6 and IL-8 may have a role in discerning the extent of disease in this condition. This initial step in systemically studying the role of cytokines in this disease may ultimately lead to the development of molecular indicators to aid in diagnosis and differentiate appendicitis from other conditions.