Faculty Bibliography

BACKGROUND: Temporal artery biopsy is performed in patients suspected of having giant cell arteritis. This study was conducted to evaluate clinical and laboratory criteria correlating with positive biopsy results in an effort to limit the number of negative biopsies performed. METHODS: A retrospective review was performed of patients who underwent temporal artery biopsy at two urban medical centers from 2002 to 2009. A multivariate analysis of patient demographics, clinically relevant signs and symptoms, laboratory data, and pathologic outcomes was performed. RESULTS: Temporal artery biopsy histologically confirmed giant cell arteritis in 24% of cases. The mean age of those with disease was 77.8 y and those without were 73.1 y; age was found to be statically significant (P = 0.0227); 76% were female and 24% were male; gender was not significant (P = 0.9594); 42% were Caucasian (39% had a positive temporal artery biopsy), 27% were Hispanic (17% positive), and 31% of the patients were African-American (3% positive); ethnicity was significant (P = 0.0005). The PPV of elevated ESR was 27%; sensitivity was 100%; specificity was 16%. A history of headache or visual disturbance was not predictive of a positive biopsy CONCLUSION: Fewer negative biopsy results may be achieved by screening patients with normal ESR or lower risk patients with other modalities.

BACKGROUND:There continues to be controversy about the necessity of interval appendectomy for delayed presentation of acute appendicitis. While recent studies suggest that the risk of recurrent disease is small, the risk of interval appendectomy is also small and does provide histologic identification and usually definitive treatment of the right lower quadrant inflammatory process. METHODS:A retrospective analysis of medical records gathered from 2002 to 2007 at a major teaching hospital of 986 adult patients over the age of 13 with appendicitis were analyzed. Forty-six patients (5%) were found to have right lower quadrant abscess or phlegmon, and were managed with intravenous antibiotics. Some patients also underwent percutaneous drainage. These patients were then readmitted 6 to 26 wk later for an elective laparoscopic interval appendectomy. RESULTS:There were 19 males and 27 females with an average age of 43 y. Ninety-four percent of the appendectomies were completed laparoscopically; 16% of patients were found to have a normal or obliterated appendix on pathologic evaluation and likely did not benefit from interval appendectomy. On the other hand, 84% of patients had persistent acute appendicitis, chronic appendicitis, evidence of inflammatory bowel disease, or neoplasm identified, and likely benefited from surgical appendectomy. CONCLUSIONS:Interval appendectomy provides diagnostic and therapeutic benefit to patients who present with a right lower quadrant abdominal inflammatory focus, and should be carefully considered in all adult patients.

BACKGROUND: There are few studies that compare the incidence of incisional hernia following elective laparoscopic colon resection to open colectomy and determine the risk factors for its development. METHODS: Elective open and laparoscopic colon resections performed between February 2002 and May 2007 were reviewed. In the laparoscopic group, mesenteric transection was performed via intracorporeal division for left-sided colectomy and via extracorporeal technique for right-sided colectomy. The ileocolic anastomosis was performed by extracorporeal stapling for right colectomies and by intracorporeal for left colectomies. RESULTS: Two hundred eighteen patients (mean age 62 years, 52% male) underwent elective colon resection (50% open, 5% hand-assisted, and 45% laparoscopic). Six percent of the cases that started as laparoscopic were converted and are included in the open group. Mean follow-up was 26 months. The overall incisional hernia rate was 16% (open and minimally invasive group 17% vs 15%, P = .14). Hernia was not dependent on the type of resection, indication, or extraction site. Body mass index >36 kg/m(2), male gender, and surgical site infection were risk factors for hernia development. CONCLUSIONS: Laparoscopic colectomy does not reduce the development of incisional hernia.

Bacteremia is a common complication of pneumonia with Klebsiella pneumoniae. In the previous work, we have shown that the lipopolysaccharide (LPS) O-antigen in K. pneumoniae O1:K2 contributes to lethality during pneumonia in part by promoting bacteremia. In the current work, we studied an O-antigen-deficient K. pneumoniae strain to further evaluate this polysaccharide's role in bloodstream infection. Cultured macrophage and murine bacteremia models were studied. In vitro, O-antigen-deficient bacteria, compared with wild-type organisms, were stronger activators of the murine alveolar macrophage cell line MH-S as assessed by nuclear localization of RelA/p65 and by secretion of cytokines and chemokines. O-antigen-deficient Klebsiellae were also more susceptible to killing by murine neutrophils. In vivo, the absence of O-antigen allowed more rapid and complete clearance of bacteria from the bloodstream, liver, and spleen after intravenous injection in mice. Survival was also greater among animals infected with bacteria missing the O-antigen. Gene expression profiling (via reverse transcriptase-polymerase chain reaction of 84 inflammatory mediator complementary DNA) revealed that by 24 h postinfection, the livers and spleens of animals infected with O-antigen-deficient organisms had significantly downregulated cytokine and chemokine expression compared with wild-type infected animals. The O-antigen surface carbohydrate of O1:K2 serotype K. pneumoniae appears to contribute to bacterial virulence by lessening the activation of macrophages, conveying resistance to killing by neutrophils, and by promoting persistent infection in the blood, liver, and spleen after the onset of bacteremia.