Marisa Cevasco

Ventral Hernia Repair with Synthetic, Composite, and Biologic Mesh: Characteristics, Indications, and Infection Profile

BACKGROUND A variety of mesh materials are available for ventral hernia repair (VHR), each with a unique set of characteristics. Surgeons are offered an ever-expanding selection of products, making a review of the available materials timely. METHODS Current surgical literature is reviewed to describe the different types of synthetic mesh, the indications for the use of each type, their relative risks of infection, and other benefits and shortcomings. We also review clinical studies demonstrating outcomes, efficacy, and use of the meshes in different surgical settings, including laparoscopic hernia repair and special situations such as infection or large abdominal wall defects. RESULTS Three main types of prosthetic mesh are available. Synthetic mesh, such as polypropylene (PP) or polyester, is characterized by high tensile strength and vigorous tissue ingrowth, but is unsuitable for intra-abdominal placement because of its tendency to induce bowel adhesions. Composite, or barrier-coated, mesh is a dual-sided prosthetic having a synthetic parietal side to promote a strong repair and a visceral surface that repels tissue ingrowth and decreases adhesion formation. Biologic mesh is a collagen-based human, porcine, or bovine scaffold that may be implanted in the extra- or intra-peritoneal position. Biologic mesh is used frequently in the setting of infected or contaminated surgical incisions. CONCLUSIONS Synthetic PP mesh is an appropriate, durable material for extra-peritoneal placement in uncomplicated, clean VHR. Expanded polytetrafluoroethylene and composite meshes are suitable for intraperitoneal placement during laparoscopic VHR. Biologic meshes may be appropriate for contaminated fields or other special situations, but there is no consensus on when or how to use them.

Validating the patient safety indicators in the Veterans Health Administration: do they accurately identify true safety events?

Background:The Agency for Healthcare Research and Quality (AHRQ) Patient Safety Indicators (PSIs) use administrative data to detect potentially preventable in-hospital adverse events. However, few studies have determined how accurately the PSIs identify true safety events. Objectives:We examined the criterion validity, specifically the positive predictive value (PPV), of 12 selected PSIs using clinical data abstracted from the Veterans Health Administration (VA) electronic medical record as the gold standard. Methods:We identified PSI-flagged cases from 28 representative hospitals by applying the AHRQ PSI software (v.3.1a) to VA fiscal year 2003 to 2007 administrative data. Trained nurse-abstractors used standardized abstraction tools to review a random sample of flagged medical records (112 records per PSI) for the presence of true adverse events. Interrater reliability was assessed. We evaluated PPVs and associated 95% confidence intervals of each PSI and examined false positive (FP) cases to determine why they were incorrectly flagged and gain insight into how each PSI might be improved. Results:PPVs ranged from 28% (95% CI, 15%−43%) for Postoperative Hip Fracture to 87% (95% CI, 79%−92%) for Postoperative Wound Dehiscence. Common reasons for FPs included conditions that were present on admission (POA), coding errors, and lack of coding specificity. PSIs with the lowest PPVs had the highest proportion of FPs owing to POA. Conclusions:Overall, PPVs were moderate for most of the PSIs. Implementing POA codes and using more specific ICD-9-CM codes would improve their validity. Our results suggest that additional coding improvements are needed before the PSIs evaluated herein are used for hospital reporting or pay for performance.

Late outcomes comparison of nonelderly patients with stented bioprosthetic and mechanical valves in the aortic position: A propensity-matched analysis

OBJECTIVE Our study compares late mortality and valve-related morbidities between nonelderly patients (aged <65 years) undergoing stented bioprosthetic or mechanical valve replacement in the aortic position. METHODS We identified 1701 consecutive patients aged <65 years who underwent aortic valve replacement between 1992 and 2011. A stented bioprosthetic valve was used in 769 patients (45%) and a mechanical valve was used in 932 patients (55%). A stepwise logistic regression propensity score identified a subset of 361 evenly matched patient-pairs. Late outcomes of death, reoperation, major bleeding, and stroke were assessed. RESULTS Follow-up was 99% complete. The mean age in the matched cohort was 53.9 years (bioprosthetic valve) and 53.2 years (mechanical valve) (P=.30). Fifteen additional measurable variables were statistically similar for the matched cohort. Thirty-day mortality was 1.9% (bioprosthetic valve) and 1.4% (mechanical valve) (P=.77). Survival at 5, 10, 15, and 18 years was 89%, 78%, 65%, and 60% for patients with bioprosthetic valves versus 88%, 79%, 75%, and 51% for patients with mechanical valves (P=.75). At 18 years, freedom from reoperation was 95% for patients with mechanical valves and 55% for patients with bioprosthetic valves (P=.002), whereas freedom from a major bleeding event favored patients with bioprosthetic valves (98%) versus mechanical valves (78%; P=.002). There was no difference in stroke between the 2 matched groups. CONCLUSIONS In patients aged <65 years, despite an increase in the rate of reoperation with stented bioprosthetic valves and an increase in major bleeding events with mechanical valves, there is no significant difference in mortality at late follow-up.

Medical and surgical readmissions in the Veterans Health Administration: what proportion are related to the index hospitalization?

Background:Readmissions are an attractive quality measure because they offer a broad view of quality beyond the index hospitalization. However, the extent to which medical or surgical readmissions reflect quality of care is largely unknown, because of the complexity of factors related to readmission. Identifying those readmissions that are clinically related to the index hospitalization is an important first step in closing this knowledge gap. Objectives:The aims of this study were to examine unplanned readmissions in the Veterans Health Administration, identify clinically related versus unrelated unplanned readmissions, and compare the leading reasons for unplanned readmission between medical and surgical discharges. Methods:We classified 2,069,804 Veterans Health Administration hospital discharges (Fiscal Years 2003–2007) into medical/surgical index discharges with/without readmissions per their diagnosis-related groups. Our outcome variable was “all-cause” 30-day unplanned readmission. We compared medical and surgical unplanned readmissions (n=217,767) on demographics, clinical characteristics, and readmission reasons using descriptive statistics. Results:Among all unplanned readmissions, 41.5% were identified as clinically related. Not surprisingly, heart failure (10.2%) and chronic obstructive pulmonary disease (6.5%) were the top 2 reasons for clinically related readmissions among medical discharges; postoperative complications (ie, complications of surgical procedures and medical care or complications of devices) accounted for 70.5% of clinically related readmissions among surgical discharges. Conclusions:Although almost 42% of unplanned readmissions were identified as clinically related, the majority of unplanned readmissions were unrelated to the index hospitalization. Quality improvement interventions targeted at processes of care associated with the index hospitalization are likely to be most effective in reducing clinically related readmissions. It is less clear how to reduce nonclinically related readmissions; these may involve broader factors than inpatient care.

Recurrence of mitral regurgitation after partial versus complete mitral valve ring annuloplasty for functional mitral regurgitation.

OBJECTIVES Both partial and complete annuloplasty rings are used for mitral valve repair for patients with functional mitral regurgitation (FMR). We sought to determine if recurrence of mitral regurgitation (MR) is affected by the type of ring used. METHODS Five hundred forty-eight patients diagnosed with FMR underwent mitral valve repair with ring annuloplasty between 1998 and 2008 in our institution. Medical records were reviewed retrospectively for clinical and echocardiographic data to determine the presence of recurrent MR (defined as moderate or severe). RESULTS Among 479 patients for whom postoperative echocardiographic data were available, recurrent MR occurred less frequently in the complete versus partial ring group (20 of 209 [10%] vs 56 of 270 [21%] patients; P = .001), despite lower preoperative ejection fractions in the complete ring group (median, 35%; interquartile range, 25%-45% vs median, 40%; interquartile range, 30%-55%; P < .001). Kaplan-Meier analysis demonstrated greater freedom from recurrent MR in the complete ring group (108 vs 103 months; P = .001). Risk-matched propensity analysis of 102 patients per group (area under the curve, 0.824; 95% confidence interval, 0.788-0.861; P < .001) also demonstrated that complete ring recipients had greater freedom from recurrent MR than partial ring recipients by univariate analysis (7 [7%] vs 17 [17%] patients; P = .049), and a trend toward greater freedom by Kaplan-Meier analysis (110 vs 104 months; P = .068). CONCLUSIONS The use of complete mitral annuloplasty rings provides improved freedom from recurrent MR in patients with FMR.

Postoperative Recurrence of Mitral Regurgitation After Annuloplasty for Functional Mitral Regurgitation

BACKGROUND We investigated predictive factors of postoperative recurrence of mitral regurgitation (MR) after mitral valve annuloplasty for functional ischemic MR. METHODS This study was a retrospective review of patients with functional MR who underwent mitral ring annuloplasty at our institution from 1998 to 2008. Records were reviewed for perioperative variables, including echocardiographic measurements. Recurrence was defined as MR grade moderate (3+) or greater on any postoperative echocardiogram. RESULTS Of 548 patients who underwent mitral annuloplasty for functional MR, echocardiogram reports were available for review for 250. These patients comprised the study cohort. There were 154 patients with concomitant coronary artery bypass grafting. The left ventricular (LV) end-diastolic (LVED) index was calculated by dividing the LVED dimension by body surface area (BSA). A high LVED index (>3.5 cm/m2) was predictive of MR recurrence (p=0.047): the recurrence rate was 20.3% (13 of 64) in high-index patients and 10.2% (19 of 186) in low-index (<3.5 cm/m2) patients. Median recurrence-free survival was 35 months (range, 19 to 59 months) in high-LVED-index patients and 46.5 months (range, 22 to 75 months) in low-LVED-index patients (p=0.048). Preoperative MR severity and LV ejection fraction were not predictive of MR recurrence. CONCLUSIONS Careful analysis of the preoperative echocardiogram using a novel, easily calculated variable, the LVED index, may help identify patients who are at greater risk for MR recurrence and reduced survival. Such information could prompt consideration of alternative or additional interventions in these patients.

How Valid is the AHRQ Patient Safety Indicator “Postoperative Hemorrhage or Hematoma”?

BACKGROUND Postoperative hemorrhage or hematoma (PHH), an Agency for Healthcare Research and Quality Patient Safety Indicator, uses administrative data to detect cases of potentially preventable postsurgical bleeding requiring a reparative procedure. How accurately it identifies true events is unknown. We therefore determined PHHs positive predictive value. STUDY DESIGN Using Patient Safety Indicator software (v.3.1a) and fiscal year 2003-2007 discharge data from 28 Veterans Health Administration hospitals, we identified 112 possible cases of PHH. Based on medical record abstraction, we characterized cases as true (TPs) or false positives (FPs), calculated positive predictive value, and analyzed FPs to ascertain reasons for incorrect identification and TPs to determine PHH-associated clinical consequences and risk factors. RESULTS Eighty-four cases were TPs (positive predictive value, 75%; 95% CI, 66-83%); 63% had a hematoma diagnosis, 30% had a hemorrhage diagnosis, 7% had both. Reasons for FPs included events present on admission (29%); hemorrhage/hematoma identified and controlled during the original procedure rather than postoperatively (21%); or postoperative hemorrhage/hematoma that did not require a procedure (18%). Most TPs (82%) returned to the operating room for hemorrhage/hematoma management; 64% required blood products and 7% died in-hospital. The most common index procedures resulting in postoperative hemorrhage/hematoma were vascular (38%); 56% were performed by a physician-in-training (under supervision). We found no substantial association between physician training status or perioperative anticoagulant use and bleeding risk. CONCLUSIONS PHHs accuracy could be improved by coding enhancements, such as adopting present on admission codes or associating a timing factor with codes dealing with bleeding control. The ability of PHH to identify events representing quality of care problems requires additional evaluation.

Quality measurement and improvement in general surgery.

Increasing emphasis is being placed on health care quality measurement and improvement in the US. Within general surgery, several sophisticated quality-measurement and outcomes systems have been developed. These include the National Surgical Quality Improvement Program, the use of selective referral and centers of excellence, the Surgical Care Improvement Project, and the World Health Organization Surgical Safety Checklist. This article reviews each of these quality-improvement initiatives, highlights their relative contributions, and discusses future directions of quality improvement within general surgery.

Detecting adverse events in surgery: comparing events detected by the Veterans Health Administration Surgical Quality Improvement Program and the Patient Safety Indicators

BACKGROUND The Patient Safety Indicators (PSIs) use administrative data to screen for select adverse events (AEs). In this study, VA Surgical Quality Improvement Program (VASQIP) chart review data were used as the gold standard to measure the criterion validity of 5 surgical PSIs. Independent chart review was also used to determine reasons for PSI errors. METHODS The sensitivity, specificity, and positive predictive value of PSI software version 4.1a were calculated among Veterans Health Administration hospitalizations (2003-2007) reviewed by VASQIP (n = 268,771). Nurses re-reviewed a sample of hospitalizations for which PSI and VASQIP AE detection disagreed. RESULTS Sensitivities ranged from 31% to 68%, specificities from 99.1% to 99.8%, and positive predictive values from 31% to 72%. Reviewers found that coding errors accounted for some PSI-VASQIP disagreement; some disagreement was also the result of differences in AE definitions. CONCLUSIONS These results suggest that the PSIs have moderate criterion validity; however, some surgical PSIs detect different AEs than VASQIP. Future research should explore using both methods to evaluate surgical quality.

How Valid is the AHRQ Patient Safety Indicator “Postoperative Physiologic and Metabolic Derangement”?

BACKGROUND The Agency for Healthcare Research and Quality Patient Safety Indicator postoperative physiologic and metabolic derangement (PMD) uses ICD-9-CM codes to screen for potentially preventable acute kidney injury (AKI) requiring dialysis plus diabetes-related complications after elective surgery. Data on PMDs accuracy in identifying true events are limited. We examined the indicators positive predictive value (PPV) in the Veterans Health Administration (VA). STUDY DESIGN Trained abstractors reviewed medical records of 119 PSI software-flagged PMD cases. We calculated PPVs overall and separately for renal- and diabetes-related complications. We also examined false positives to determine reasons for incorrect identification, and true positives to determine PMD-related outcomes and risk factors. RESULTS Overall 75 cases were true positives (PPV 63%, 95% CI 54% to 72%); 73 of 104 AKI cases were true positives (PPV 70%, 60% to 79%); only 2 of 15 diabetes cases were true positives (PPV 13%, 2% to 40%). Of all false positives, 70% represented nonelective admissions and 23% had the complication present on admission. Of AKI true positives, 37% died and 26% were discharged on dialysis; 55% had chronic kidney disease (≥ stage 3) present on admission. Cardiac surgery represented the largest category of AKI-associated index procedures (30%). AKI was most commonly attributed to perioperative renal hypoperfusion (84% of true positives), followed by nephrotoxins (33%) including contrast (11%). CONCLUSIONS Due to its low PPV, we recommend removing diabetes complications from the indicator and focusing on AKI. PMDs PPV could be significantly improved by using present-on-admission codes, and specific to the VA, by introduction of admission status codes. Many PMD-identified cases appeared to be at high risk based on patient- and procedure-related factors. The degree to which such cases are truly preventable events requires further assessment.