Steve Kwon

Importance of perioperative glycemic control in general surgery: A report from the surgical care and outcomes assessment program

Objective:To determine the relationship of perioperative hyperglycemia and insulin administration on outcomes in elective colon/rectal and bariatric operations. Background:There is limited evidence to characterize the impact of perioperative hyperglycemia and insulin on adverse outcomes in patients, with and without diabetes, undergoing general surgical procedures. Methods:The Surgical Care and Outcomes Assessment Program is a Washington State quality improvement benchmarking-based initiative. We evaluated the relationship of perioperative hyperglycemia (>180 mg/dL) and insulin administration on mortality, reoperative interventions, and infections for patients undergoing elective colorectal and bariatric surgery at 47 participating hospitals between fourth quarter of 2005 and fourth quarter of 2010. Results:Of the 11,633 patients (55.4 ± 15.3 years; 65.7% women) with a serum glucose determination on the day of surgery, postoperative day 1, or postoperative day 2, 29.1% of patients were hyperglycemic. After controlling for clinical factors, those with hyperglycemia had a significantly increased risk of infection [odds ratio (OR) 2.0; 95% confidence interval (CI), 1.63–2.44], reoperative interventions (OR, 1.8; 95% CI, 1.41–2.3), and death (OR, 2.71; 95% CI, 1.72–4.28). Increased risk of poor outcomes was observed both for patients with and without diabetes. Those with hyperglycemia on the day of surgery who received insulin had no significant increase in infections (OR, 1.01; 95% CI, 0.72–1.42), reoperative interventions (OR, 1.29; 95% CI, 0.89–1.89), or deaths (OR, 1.21; 95% CI, 0.61–2.42). A dose-effect relationship was found between the effectiveness of insulin-related glucose control (worst 180–250 mg/dL, best <130 mg/dL) and adverse outcomes. Conclusions:Perioperative hyperglycemia was associated with adverse outcomes in general surgery patients with and without diabetes. However, patients with hyperglycemia who received insulin were at no greater risk than those with normal blood glucoses. Perioperative glucose evaluation and insulin administration in patients with hyperglycemia are important quality targets.

Progress in the diagnosis of appendicitis: a report from Washington State's Surgical Care and Outcomes Assessment Program.

Background and Objectives:Studies suggest that computed tomography and ultrasonography can effectively diagnose and rule out appendicitis, safely reducing negative appendectomies (NAs); however, some within the surgical community remain reluctant to add imaging to clinical evaluation of patients with suspected appendicitis. The Surgical Care and Outcomes Assessment Program (SCOAP) is a physician-led quality initiative that monitors performance by benchmarking processes of care and outcomes. Since 2006, accurate diagnosis of appendicitis has been a priority for SCOAP. The objective of this study was to evaluate the association between imaging and NA in the general community. Methods:Data were collected prospectively for consecutive appendectomy patients (age > 15 years) at nearly 60 hospitals. SCOAP data are obtained directly from clinical records, including radiological, operative, and pathological reports. Multivariate logistic regression models were used to examine the association between imaging and NA. Tests for trends over time were also conducted. Results:Among 19,327 patients (47.9% female) who underwent appendectomy, 5.4% had NA. Among patients who were imaged, frequency of NA was 4.5%, whereas among those who were not imaged, it was 15.4% (P < 0.001). This association was consistent for men (3% vs 10%, P < 0.001) and for women of reproductive age (6.9% vs 24.7%, P < 0.001). In a multivariate model adjusted for age, sex, and white blood cell count, odds of NA for patients not imaged were 3.7 times the odds for those who received imaging (95% CI: 3.0–4.4). Among SCOAP hospitals, use of imaging increased and NA decreased significantly over time; frequency of perforation was unchanged. Conclusions:Patients who were not imaged during workup for suspected appendicitis had more than 3 times the odds of NA as those who were imaged. Routine imaging in the evaluation of patients suspected to have appendicitis can safely reduce unnecessary operations. Programs such as SCOAP improve care through peer-led, benchmarked practice change.

Sentinel lymph node biopsy for high-risk cutaneous squamous cell carcinoma: clinical experience and review of literature

High-risk cutaneous squamous cell carcinoma (SCC) is associated with an increased risk of metastases. The role of sentinel lymph node (SLN) biopsy in these patients remains unclear. To address this uncertainty, we collected clinical data on six patients with clinical N0 high-risk SCC that underwent SLN biopsy between 1999 and 2006 and performed a literature review of SLN procedures for SCC to study the utility of SLN biopsy. There were no positive SLN identified among six cases and there was one local and one distant recurrence on follow-up. Literature review identified 130 reported cases of SLN biopsy for SCC. The SLN positivity rate was 14.1%, 10.1%, and 18.6%; false negative rate was 15.4%, 0%, and 22.2%; and the negative predictive value was 97.8%, 100%, and 95.2% for all sites, head/neck, and truncal/extremity sites, respectively. SLN biopsy remains an investigational staging tool in clinically node-negative high-risk SCC patients. The higher false negative rate and lower negative predictive value among SCC of the trunk/extremity compared to SCC of the head/neck sites suggests a more cautious approach when treating patients with the former. Given the paucity of long-term follow up, an emphasis is placed upon the need for close surveillance regardless of SLN status.

β-Blocker Continuation After Noncardiac Surgery: A Report From the Surgical Care and Outcomes Assessment Program

BACKGROUND Despite limited evidence of effect, β-blocker continuation has become a national quality improvement metric. OBJECTIVE To determine the effect of β-blocker continuation on outcomes in patients undergoing elective noncardiac surgery. DESIGN, SETTING, AND PATIENTS The Surgical Care and Outcomes Assessment Program is a Washington quality improvement benchmarking initiative based on clinical data from more than 55 hospitals. Linking Surgical Care and Outcomes Assessment Program data to Washingtons hospital admission and vital status registries, we studied patients undergoing elective colorectal and bariatric surgical procedures at 38 hospitals between January 1, 2008, and December 31, 2009. MAIN OUTCOME MEASURES Mortality, cardiac events, and the combined adverse event of cardiac events and/or mortality. RESULTS Of 8431 patients, 23.5% were taking β-blockers prior to surgery (mean [SD] age, 61.9 [13.7] years; 63.0% were women). Treatment with β-blockers was continued on the day of surgery and during the postoperative period in 66.0% of patients. Continuation of β-blockers both on the day of surgery and postoperatively improved from 57.2% in the first quarter of 2008 to 71.3% in the fourth quarter of 2009 (P value <.001). After adjusting for risk characteristics, failure to continue β-blocker treatment was associated with a nearly 2-fold risk of 90-day combined adverse event (odds ratio, 1.97; 95% CI, 1.19-3.26). The odds were even greater among patients with higher cardiac risk (odds ratio, 5.91; 95% CI, 1.40- 25.00). The odds of combined adverse events continued to be elevated 1 year postoperatively (odds ratio, 1.66; 95% CI, 1.08-2.55). CONCLUSIONS β-Blocker continuation on the day of and after surgery was associated with fewer cardiac events and lower 90-day mortality. A focus on β-blocker continuation is a worthwhile quality improvement target and should improve patient outcomes.

Routine Leak Testing in Colorectal Surgery in the Surgical Care and Outcomes Assessment Program

OBJECTIVE To evaluate the effect of routine anastomotic leak testing (performed to screen for leaks) vs selective testing (performed to evaluate for a suspected leak in a higher-risk or technically difficult anastomosis) on outcomes in colorectal surgery because the value of provocative testing of colorectal anastomoses as a quality improvement metric has yet to be determined. DESIGN Observational, prospectively designed cohort study. SETTING Data from Washington states Surgical Care and Outcomes Assessment Program (SCOAP). PATIENTS Patients undergoing elective left-sided colon or rectal resections at 40 SCOAP hospitals from October 1, 2005, to December 31, 2009. INTERVENTIONS Use of leak testing, distinguishing procedures that were performed at hospitals where leak testing was selective (<90% use) or routine (≥ 90% use) in a given calendar quarter. MAIN OUTCOME MEASURE Adjusted odds ratio of a composite adverse event (CAE) (unplanned postoperative intervention and/or in-hospital death) at routine testing hospitals. RESULTS Among 3449 patients (mean [SD] age, 58.8 [14.8] years; 55.0% women), the CAE rate was 5.5%. Provocative leak testing increased (from 56% in the starting quarter to 76% in quarter 16) and overall rates of CAE decreased (from 7.0% in the starting quarter to 4.6% in quarter 16; both P ≤ .01) over time. Among patients at hospitals that performed routine leak testing, we found a reduction of more than 75% in the adjusted risk of CAEs (odds ratio, 0.23; 95% CI, 0.05-0.99). CONCLUSION Routine leak testing of left-sided colorectal anastomoses appears to be associated with a reduced rate of CAEs within the SCOAP network and meets many of the criteria of a worthwhile quality improvement metric.

Akt and mTORC1 Have Different Roles During Liver Tumorigenesis in Mice

BACKGROUND & AIMS Phosphatidylinositide 3-kinase (PI3K) is deregulated in many human tumor types, including primary liver malignancies. The kinase v-akt murine thymoma viral oncogene homolog 1 (Akt) and mammalian target of rapamycin complex (mTORC1) are effectors of PI3K that promote cell growth and survival, but their individual roles in tumorigenesis are not well defined. METHODS In livers of albumin (Alb)-Cre mice, we selectively deleted tuberous sclerosis (Tsc)1, a negative regulator of Ras homolog enriched in brain and mTORC1, along with Phosphatase and tensin homolog (Pten), a negative regulator of PI3K. Tumor tissues were characterized by histologic and biochemical analyses. RESULTS The Tsc1fl/fl;AlbCre, Ptenfl/fl;AlbCre, and Tsc1fl/fl;Ptenfl/fl;AlbCre mice developed liver tumors that differed in size, number, and histologic features. Livers of Tsc1fl/fl;AlbCre mice did not develop steatosis; tumors arose later than in the other strains of mice and were predominantly hepatocellular carcinomas. Livers of the Ptenfl/fl;AlbCre mice developed steatosis and most of the tumors that formed were intrahepatic cholangiocarcinomas. Livers of Tsc1fl/fl;Ptenfl/fl;AlbCre formed large numbers of tumors, of mixed histologies, with the earliest onset of any strain, indicating that loss of Tsc1 and Pten have synergistic effects on tumorigenesis. In these mice, the combination of rapamycin and MK2206 was more effective in reducing liver cell proliferation and inducing cell death than either reagent alone. Tumor differentiation correlated with Akt and mTORC1 activities; the ratio of Akt:mTORC1 activity was high throughout the course of intrahepatic cholangiocarcinomas development and low during hepatocellular carcinoma development. Compared with surrounding nontumor liver tissue, tumors from all 3 strains had increased activities of Akt, mTORC1, and mitogen-activated protein kinase and overexpressed fibroblast growth factor receptor 1. Inhibition of fibroblast growth factor receptor 1 in Tsc1-null mice suppressed Akt and mitogen-activated protein kinase activities in tumor cells. CONCLUSIONS Based on analyses of knockout mice, mTORC1 and Akt have different yet synergistic effects during the development of liver tumors in mice.

Perioperative Pharmacologic Prophylaxis for Venous Thromboembolism in Colorectal Surgery

BACKGROUND To determine the effectiveness of pharmacologic prophylaxis in preventing clinically relevant venous thromboembolic (VTE) events and deaths after surgery. The Surgical Care Improvement Project recommends that VTE pharmacologic prophylaxis be given within 24 hours of the operation. The bulk of evidence supporting this recommendation uses radiographic end points. STUDY DESIGN The Surgical Care and Outcomes Assessment Program is a Washington State quality improvement initiative with data linked to hospital admission/discharge and vital status records. We compared the rates of death, clinically relevant VTE, and a composite adverse event (CAE) in the 90 days after elective, colon/rectal resections, based on receipt of pharmacologic prophylaxis (within 24 hours of surgery) at 36 Surgical Care and Outcomes Assessment Program hospitals (2005-2009). RESULTS Of 4,195 (mean age 61.1 ± 15.6 years; 54.1% women) patients, 56.5% received pharmacologic prophylaxis. Ninety-day death (2.5% vs 1.6%; p = 0.03), VTE (1.8% vs 1.1%; p = 0.04), and CAE (4.2% vs 2.5%; p = .002) were lower in those who received pharmacologic prophylaxis. After adjustment for patient and procedure characteristics, the odds were 36% lower for CAE (odds ratio = 0.64; 95% CI, 0.44-0.93) with pharmacologic prophylaxis. In any given quarter, hospitals where patients more often received pharmacologic prophylaxis (highest tertile of use) had the lowest rates of CAE (2.3% vs 3.6%; p = 0.05) compared with hospitals in the lowest tertile. CONCLUSIONS Using clinical end points, this study demonstrates the effectiveness of VTE pharmacologic prophylaxis in patients having elective colorectal surgery. Hospitals that used pharmacologic prophylaxis more often had the lowest rates of adverse events.

Development of a Surgical Capacity Index: Opportunities for Assessment and Improvement

BackgroundSignificant gaps exist in the provision of surgical care in low- and middle-income countries (LMICs). The purpose of this study was to develop a metric to monitor surgical capacity in LMICs.MethodsThe World Health Organization developed a survey called the Tool for Situational Analysis to Assess Emergency and Essential Surgical Care. Using this tool, we developed a surgical capacity scoring index and assessed its usefulness with data from Sierra Leone, Liberia, and the Solomon Islands.ResultsThere were data from 10 hospitals in Sierra Leone, 16 hospitals in Liberia, and 9 hospitals in the Solomon Islands. The levels of surgical capacity were created using our scoring index based on a possible 100 points: level 1 for hospitals with <50 points, level 2 with 50–70 points, level 3 with 70–80 points, and level 4 with >80 points. In Sierra Leone, 44% of the hospitals had a surgical capacity rating of level 1, 50% level 2, and 10% level 3. In Liberia, 37.5% of the hospitals had a surgical capacity rating of level 1, 56.3% level 2, and only one hospital level 3. For Sierra Leone and Liberia, two factors—infrastructure and personnel—had the greatest deficits. In the Solomon Islands, 44.4% of the hospitals had their surgical capacity rated at level 1, 22.2% at level 2, 11.1% at level 3, and 22.2% at level 4.ConclusionsPending pilot testing for reliability and validity, it appears that a systematic hospital surgical capacity index can identify areas for improvement and provide an objective measure for monitoring changes over time.

Surgical management of hepatocellular carcinoma after Fontan procedure

The Fontan operation has successfully prolonged the lives of patients born with single-ventricle physiology. A long-term consequence of post-Fontan elevation in systemic venous pressure and low cardiac output is chronic liver inflammation and cirrhosis, which lead to an increased risk of hepatocellular carcinoma (HCC). Surgical management of patients with post-Fontan physiology and HCC is challenging, as the requirement for adequate preload in order to sustain cardiac output conflicts with the low central venous pressure (CVP) that minimizes blood loss during hepatectomy. Consequently, liver resection is rarely performed, and most reports describe nonsurgical treatments for locoregional control of the tumors in these patients. Here, we present a multidisciplinary approach to a successful surgical resection of a HCC in a patient with Fontan physiology.

Conflicting Hemodynamic Goals in an Adult Patient With Fontan Physiology Presenting for Resection of a Hepatocellular Carcinoma.

THE FONTAN PROCEDURE is used to treat children with congenital heart disease resulting in a single functional ventricle. Caval flow is directed to the pulmonary arteries without the aid of a subpulmonic ventricle. The absence of a right ventricle requires chronically elevated central venous pressure (CVP), which must be maintained at a sufficient level to drive pulmonary blood flow and maintain cardiac output. This pressure is transmitted to the liver, causing chronic hepatic congestion, which may be exacerbated by lower mean arterial perfusion pressures and chronic hypoxemia. These factors contribute to the increased rates of liver inflammation, gastroesophageal varices, liver nodules, and increasing reports of hepatocellular carcinoma (HCC) in these patients. In patients with Fontan circulation, a precipitous drop in preload can result in low cardiac output and hypotension. In patients requiring liver resection, elevated CVP is transmitted via the hepatic veins in the surgical bed, resulting in increased intraoperative bleeding. This leads to the practice of targeting CVP of less than 5 mmHg for major hepatectomy. These conflicting hemodynamic goals are examined in this case report.