OBJECTIVE::

To investigate the association between obesity and perioperative acute kidney injury (AKI), controlling for preoperative kidney dysfunction.

BACKGROUND::

More than 30% of patients older than 60 years are obese and, therefore, at risk for kidney disease. Postoperative AKI is a significant problem.

METHODS::

We performed a matched case-control study of patients enrolled in the Obesity and Surgical Outcomes Study, using data of Medicare claims enriched with detailed chart review. Each AKI patient was matched with a non-AKI control similar in procedure type, age, sex, race, emergency status, transfer status, baseline estimated glomerular filtration rate, admission APACHE score, and the risk of death score with fine balance on hospitals.

RESULTS::

We identified 514 AKI cases and 694 control patients. Of the cases, 180 (35%) followed orthopedic procedures and 334 (65%) followed colon or thoracic surgery. After matching, obese patients undergoing a surgical procedure demonstrated a 65% increase in odds of AKI within 30 days from admission (odds ratio = 1.65, P < 0.005) when compared with the nonobese patients. After adjustment for potential confounders, the odds of postoperative AKI remained elevated in the elderly obese (odds ratio = 1.68, P = 0.01.)

CONCLUSIONS::

Obesity is an independent risk factor for postoperative AKI in patients older than 65 years. Efforts to optimize kidney function preoperatively should be employed in this at-risk population along with keen monitoring and maintenance of intraoperative hemodynamics. When subtle reductions in urine output or a rising creatinine are observed postoperatively, timely clinical investigation is warranted to maximize renal recovery.

OBJECTIVE::

To perform a systematic review of economic evaluations of enhanced recovery pathways (ERP) for colorectal surgery.

BACKGROUND::

Although there is extensive literature investigating the clinical effectiveness of ERP, little is known regarding its cost-effectiveness.

METHODS::

A systematic literature search identified all relevant articles published between 1997 and 2012 that performed an economic evaluation of ERP for colorectal surgery. Studies were included only if their ERP included all 5 of the key components (patient information, preservation of GI function, minimization of organ dysfunction, active pain control, and promotion of patient autonomy). Quality assessment was performed using the Consensus on Health Economic Criteria instrument (scored 0-19; high quality ≥ 12). Incremental cost-effectiveness ratios were calculated if sufficient data were provided, using difference in length of stay and overall complication rates as effectiveness measures.

RESULTS::

Of a total of 263 unique records identified (253 from databases and 10 from other sources), 10 studies met our inclusion criteria and were included for full qualitative synthesis. Overall quality was poor (mean quality 7.8). Eight reported lower costs for ERP. The majority (8 of 10) of studies were performed from an institutional perspective and therefore did not include costs related to changes in productivity and other indirect costs (eg, caregiver burden). Five studies provided enough information to calculate ICERs, of which ERP was dominant (less costly and more effective) in all cases for reduction in length of stay and was dominant or potentially cost-effective in 4 and questionable (no difference in costs nor effectiveness) in 1 for reduction in overall complications.

CONCLUSIONS::

The quality of the current evidence is limited but tends to support the cost-effectiveness of ERP. There is need for well-designed trials to determine the cost-effectiveness of ERP from both the institutional and societal perspectives.

OBJECTIVE::

To examine the prognostic factors and outcomes after several types of treatments in patients with hepatocellular carcinoma (HCC) negative for hepatitis B surface antigen and hepatitis C antibody, so-called "non-B non-C HCC" using the data of a nationwide survey.

BACKGROUND::

The proportion of non-B non-C HCC is rapidly increasing in Japan.

METHODS::

A total of 4741 patients with non-B non-C HCC, who underwent hepatic resection (HR, n = 2872), radiofrequency ablation (RFA, n = 432), and transcatheter arterial chemoembolization (TACE, n = 1437) as the initial treatment, were enrolled in this study. The exclusion criteria included extrahepatic metastases and/or Child-Pugh C. Significant prognostic variables determined by a univariate analysis were subjected to a multivariate analysis using a Cox proportional hazard regression model.

RESULTS::

The degree of liver damage in the HR group was significantly lower than that in the RFA and TACE groups. The HR and TACE groups had significantly more advanced HCC than the RFA group. The 5-year survival rates after HR, RFA, and TACE were 66%, 49%, and 32%, respectively. Stratifying the survival rates, according to the TNM stage and the Japan Integrated Staging (JIS) score, showed the HR group to have a significantly better prognosis than the RFA group in the stage II and in the JIS scores "1" and "2." The multivariate analysis showed 12 independent prognostic factors. HR offers significant prognostic advantages over TACE and RFA.

CONCLUSIONS::

The findings of this large prospective cohort study indicated that HR may be recommended, especially in patients with TNM stage II and JIS scores "1" and "2" of non-B non-C HCC.

OBJECTIVE::

To demonstrate the pro-osteogenic effect of burn injury on heterotopic bone formation using a novel burn ossicle in vivo model.

BACKGROUND::

Heterotopic ossification (HO), or the abnormal formation of bone in soft tissue, is a troubling sequela of burn and trauma injuries. The exact mechanism by which burn injury influences bone formation is unknown. The aim of this study was to develop a mouse model to study the effect of burn injury on heterotopic bone formation. We hypothesized that burn injury would enhance early vascularization and subsequent bone formation of subcutaneously implanted mesenchymal stem cells.

METHODS::

Mouse adipose-derived stem cells were harvested from C57/BL6 mice, transfected with a BMP-2 adenovirus, seeded on collagen scaffolds (ossicles), and implanted subcutaneously in the flank region of 8 adult mice. Burn and sham groups were created with exposure of 30% surface area on the dorsum to 60°C water or 30°C water for 18 seconds, respectively (n = 4/group). Heterotopic bone volume was analyzed in vivo by micro-computed tomography for 3 months. Histological analysis of vasculogenesis was performed with platelet endothelial cell adhesion molecule staining. Osteogenic histological analysis was performed by Safranin O, Picrosirius red, and aniline blue staining. Qualitative analysis of heterotopic bone composition was completed with ex vivo Raman spectroscopy.

RESULTS::

Subcutaneously implanted ossicles formed heterotopic bone. Ossicles from mice with burn injuries developed significantly more bone than sham control mice, analyzed by micro-computed tomography at 1, 2, and 3 months (P < 0.05), and had enhanced early and late endochondral ossification as demonstrated by Safranin O, Picrosirius red, and aniline blue staining. In addition, burn injury enhanced vascularization of the ossicles (P < 0.05). All ossicles demonstrated chemical composition characteristic of bone as demonstrated by Raman spectroscopy.

CONCLUSIONS::

Burn injury increases the predilection to osteogenic differentiation of ectopically implanted ossicles. Early differences in vascularity correlated with later bone development. Understanding the role of burn injury on heterotopic bone formation is an important first step toward the development of treatment strategies aimed to prevent unwanted and detrimental heterotopic bone formation.

OBJECTIVE::

To validate the 2010 American Joint Committee on Cancer (AJCC) and 2006 European Neuroendocrine Tumor Society (ENETS) tumor staging systems for pancreatic neuroendocrine tumors (PanNETs) using the largest, single-institution series of surgically resected patients in the literature.

BACKGROUND::

The natural history and prognosis of PanNETs have been poorly defined because of the rarity and heterogeneity of these neoplasms. Currently, there are 2 main staging systems for PanNETs, which can complicate comparisons of reports in the literature and thereby hinder progress against this disease.

METHODS::

Univariate and multivariate analyses were conducted on the prognostic factors of survival using 326 sporadic, nonfunctional, surgically resected PanNET patients who were cared for at our institution between 1984 and 2011. Current and proposed models were tested for survival prognostication validity as measured by discrimination (Harrel's c-index, HCI) and calibration.

RESULTS::

Five-year overall-survival rates for AJCC stages I, II, and IV are 93% (88%-99%), 74% (65%-83%), and 56% (42%-73%), respectively, whereas ENETS stages I, II, III, and IV are 97% (92%-100%), 87% (80%-95%), 73% (63%-84%), and 56% (42%-73%), respectively. Each model has an HCI of 0.68, and they are no different in their ability to predict survival. We developed a simple prognostic tool just using grade, as measured by continuous Ki-67 labeling, sex, and binary age that has an HCI of 0.74.

CONCLUSIONS::

Both the AJCC and ENETS staging systems are valid and indistinguishable in their survival prognostication. A new, simpler prognostic tool can be used to predict survival and decrease interinstitutional mistakes and uncertainties regarding these neoplasms.

: To define the changing prevalence of erosion after Laparoscopic Adjustable Gastric Banding (LAGB), describing the range of clinical presentations, the approaches to treatment and the outcomes from these approaches over a 15-year study period.: A recent systematic review of the literature of erosion after LAGB identified 25 relevant studies and reported a total of 231 erosions in 15,775 patients giving an overall incidence of 1.46%. The review highlighted a broad variation of incidence from 0.2% to 33%. The review was unable to identify either common presentations or an optimal pattern of management.: Patients who underwent a primary LAGB operation between September 1994 and January 2010 by 2 surgeons (P.O.B. and W.B.) were identified in a prospectively maintained database. Those patients who had an erosion of their LAGB were identified. Presentation, operative details, demographics, body mass index, weight history, and perioperative problems were analyzed.: In total, 2986 patients were identified. All bands placed were Lap-Bands (Allergan, CA). Hundred erosions were experienced by 85 patients (2.85%) at a median time of 33 months from initial surgery to the erosion (range: 11-170 months). The rate of erosion was highest when the band was placed by the perigastric approach at 6.77%. Since the adoption of the pars flaccida approach, the rate of erosion has dropped to 1.07%. The majority of patients who had experienced an erosion (71 patients; 83.5%) experienced only 1 erosion, 13 patients (15.3%) had 2 erosions, and 1 patient had 3 erosions. The most common presentation was loss of satiety. The band has been successfully replaced in 56 patients. It has been explanted in 27 patients and 2 patients were converted to other bariatric procedures. The weight loss in patients who had a LAGB reinserted after erosion was not significantly different to the background cohort.: Erosion of LAGB is uncommon and its clinical course is benign. It is best treated with a staged surgical approach; initially, with removal and repair followed later by replacement. With this approach, weight loss is maintained and reerosion is uncommon.