Risk stratification scores in elective open abdominal aortic aneurysm repair: are they suitable for preoperative decision making?

OBJECTIVES: Risk indices help quantify the risk of cardiovascular events and death prior to making decisions about prophylactic AAA repair. This paper aims to study the predictive capabilities of 5 validated indices. DESIGN AND METHODS: A prospective observational multi-centre cohort study from August 2005 to September 2007 in Glasgow recruited 106 consecutive patients undergoing elective open AAA repair. The Glasgow Aneurysm Score (GAS), Vascular physiology only Physiological and Operative Severity Score for enUmeration of Mortality (V(p)-POSSUM), Vascular Biochemical and Haematological Outcome Model (VBHOM), Revised Cardiac Risk Index (RCRI) and Preoperative Risk Score of the Estimation of Physiological Ability and Surgical Stress Score (PRS of E-PASS) were calculated. Indices were compared using receiver operating characteristic (ROC) analysis and area under the curve (AUC) estimates. End points were all-cause mortality, Major Adverse Cardiac Events (MACE) and cardiac death. RESULTS: GAS, VBHOM and RCRI did not predict outcome. V(p)-POSSUM predicted MACE (AUC = 0.681), cardiac death (AUC = 0.762) and all-cause mortality (AUC = 0.780), as did E-PASS (AUC = 0.682, 0.821, 0.703 for MACE, cardiac death and all-cause mortality respectively). CONCLUSION: Whilst V(p)-POSSUM and E-PASS predicted outcome, the less complex RCRI and GAS performed poorly which questions the utility of decision making based on these surgical risk indices.

The influence of clinical risk factors on pre-operative B-type natriuretic peptide risk stratification of vascular surgical patients.

The role of the revised cardiac risk index in risk stratification has recently been challenged by studies reporting on the superior predictive ability of pre-operative B-type natriuretic peptides. We found that in 850 vascular surgical patients initially risk stratified using B-type natriuretic peptides, reclassification with the number of revised cardiac risk index risk factors worsened risk stratification (p < 0.05 for > 0, > 2, > 3 and > 4 risk factors, and p = 0.23 for > 1 risk factor). When evaluated with pre-operative B-type natriuretic peptides, none of the revised cardiac risk index risk factors were independent predictors of major adverse cardiac events in vascular patients. The only independent predictor was B-type natriuretic peptide stratification (OR 5.1, 95% CI 1.8-15 for the intermediate class, and OR 25, 95% CI 8.7-70 for the high-risk class). The clinical risk factors in the revised cardiac risk index cannot improve a risk stratification model based on B-type natriuretic peptides.

B-type natriuretic peptide predicts long-term survival after major non-cardiac surgery.

BACKGROUND: The prediction of long-term survival after surgery is complex. Natriuretic peptides can predict short-term postoperative cardiac morbidity and mortality. This study aims to determine the long-term prognostic significance of preoperative B-type natriuretic peptide (BNP) concentration after major non-cardiac surgery. METHODS: We conducted a prospective single-centre observational cohort study in a West of Scotland teaching hospital. Three hundred and forty-five patients undergoing major non-cardiac surgery were included. The primary endpoint was long-term all-cause mortality. RESULTS: Overall survival was 67.8% (234/345), with 27 postoperative deaths (within 42 days) and 84 deaths at subsequent follow-up (median follow-up 953 days). A BNP concentration of >87.5 pg ml(-1) best predicted mortality, and the mean survival of patients with an elevated BNP (>87.5 pg ml(-1)) was 731.9 (95% CI 613.6-850.2) days compared with 1284.6 days [(95% CI 1219.3-1350.0), P<0.001] in patients with a BNP<87.5 pg ml(-1). BNP was an independent predictor of survival. CONCLUSIONS: BNP is an independent predictor of long-term survival after major non-cardiac surgery. A simple preoperative blood test can provide predictive information on future risk of death, and potentially has a role in preoperative risk assessment.

Gastroesophageal reflux in laparoscopic sleeve gastrectomy: hiatal findings and their management influence outcome.

BACKGROUND: Sleeve gastrectomy (SG) has become a definitive treatment for morbid obesity. There is conflicting evidence on the effects of SG on gastroesophageal reflux disease (GERD). OBJECTIVE: The objective of this study was to assess whether taking an aggressive approach to managing hiatal weakness in patients undergoing SG results in an alteration in GERD symptoms. SETTING: Tertiary public hospital and private hospital, Sydney, Australia. METHODS: Patients undergoing laparoscopic extended (beginning within 2 cm from pylorus) SG were included. If evidence of weakness was present, an anterior hiatal dissection and tight suture repair was performed. If a hiatus hernia was present, formal repair was undertaken. Patients were questioned and scored on preoperative and postoperative reflux symptom frequency and severity, proton pump inhibitor (PPI) usage, current weight, and satisfaction. RESULTS: A continuous cohort of 262 patients experienced a significant reduction in heartburn frequency (P = .035) and severity (P = .017). Moderate/severe preoperative reflux (Visick score 3 and 4) often improved whether there was a defect requiring repair or not (no repair P = .02, hiatal suture P = .001, hiatus hernia repair P<.001). The severity of symptoms also improved (no repair P = 0.005, hiatal suture P<.001, hiatus hernia repair P< .001). CONCLUSION: Moderate or severe preexisting gastroesophageal reflux improved for most of our obese patients undergoing an extended SG when hiatal defects were routinely repaired. Moderate to severe preoperative reflux also improved in the average obese patient when there was no hiatal defect to repair.

B-type natriuretic peptide predicts cardiac morbidity and mortality after major surgery.

BACKGROUND: The objective of this study was to determine whether measurement of B-type natriuretic peptide (BNP) concentration before operation could be used to predict perioperative cardiac morbidity. METHODS: A prospective derivation study was performed in high-risk patients undergoing major non-cardiac surgery, with a subsequent validation study. A venous blood sample was taken the day before surgery for measurement of plasma BNP concentration. Screening for cardiac events (non-fatal myocardial infarction and cardiac death) was performed using clinical criteria, cardiac troponin I analysis and serial electrocardiography. RESULTS: Forty-one patients were recruited to the derivation cohort and 149 to the validation cohort. In the derivation cohort, the median (interquartile range) BNP concentration in the 11 patients who had a postoperative cardiac event was 210 (165-380) pg/ml, compared with 34.5 (14-70) pg/ml in those with no cardiac complications (P < 0.001). In the validation cohort, the median BNP concentration in the 15 patients who had a cardiac event was 351 (127-1034) pg/ml, compared with 30.5 (11-79.5) pg/ml in the remainder (P < 0.001). BNP concentration remained a significant outcome predictor in multivariable analysis (P < 0.001). Using receiver-operator curve analysis it was calculated that a BNP concentration of 108.5 pg/ml best predicted the likelihood of cardiac events, with a sensitivity and specificity of 87 per cent each. CONCLUSION: Preoperative serum BNP concentration predicted postoperative cardiac events in patients undergoing major non-cardiac surgery independently of other risk factors.

Measurement of process as quality control in the management of acute surgical emergencies.

BACKGROUND: Quality of care measured by adverse events cannot address errors of process that have no adverse outcomes. The aim of this study was to determine whether process could be used to assess quality of care and whether process analysis could be used to assess interventions designed to improve quality. METHODS: A single-centre prospective cohort study was performed over 12 weeks in an acute surgical admission unit. Data were collected prospectively for the first 24 h of admission on three aspects of process: documentation, general management and presentation-specific criteria. After a period of observation, the impact of three interventions (active observation, increasing awareness and issuing a job description) on the mean number of process errors per patient (process score) was compared. RESULTS: The analysis was based on 566 patients admitted with general surgical pathology. Awareness of being observed failed to improve the process score. Interventions that increased awareness of process reduced the overall process score from 4.79 to 2.38 errors per person (P < 0.001). The mean overall process score in patients with an adverse event was twice that of patients who did not have an adverse event (5.74 (95 per cent confidence interval 4.03 to 7.45) versus 3.43 (3.19 to 3.66)). CONCLUSION: Process can be measured objectively and used as a measure of quality of care. Interventions to increase awareness reduced process error rates and adverse events.

Should pre-operative troponin be a standard requirement in patients undergoing major lower extremity amputation?

OBJECTIVES: The objective of this study was to ascertain the benefit of routine pre-operative cardiac troponin I (cTnI) measurement in patients undergoing major lower extremity amputation for critical limb ischaemia. DESIGN: This was a prospective, blinded observational study. METHODS: All patients scheduled for lower extremity amputation, without evidence of unstable coronary artery disease were recruited prospectively over a period of 1 year. In addition to routine pre-operative evaluation, a blood sample was taken for measurement of serum cTnI. Post-operative screening was conducted for cardiac events with patients followed up to 6 weeks. RESULTS: Ten of the 44 patients included suffered a non-fatal myocardial infarction or died from a cardiac cause post-operatively. A rise in pre-operative cTnI was associated with a very poor outcome (two cardiac deaths and one post-operative myocardial infarction) and was the only significant predictor of post-operative cardiac events. CONCLUSION: Routine pre-operative cTnI measurement may be of use to identify patients at high risk of cardiac complication who would benefit from optimization of cardiac status or in whom surgery could be deferred.

Ten-year experience of carbon dioxide laser ablation as treatment for cutaneous recurrence of malignant melanoma.

BACKGROUND: Cutaneous recurrence of malignant melanoma is distressing for the patient, can be difficult to palliate and is resistant to treatment by conventional methods. Experience with carbon dioxide laser ablation was reviewed to determine the initial efficacy, time to recurrence, number of treatments required and length of palliation achieved. METHODS: Using a departmental database and case notes, a review was carried out of all patients undergoing laser ablation in the authors' unit between September 1992 August 2002. RESULTS: Forty-two patients received 105 (mean 2.5) treatments. The median time to recurrence was 5.2 (range 1.2-72.0) months. Twenty-three patients were still alive, with a median time from first laser ablation of 5.4 (range 0.5-10.0) years. Nineteen patients had died, a median of 0.8 (range 0.1-5.3) years after the first ablation. Ten of the 23 patients were disease-free for more than 1 year. No limbs were amputated because of failure to control disease. CONCLUSION: Laser ablation is a practical and useful method of palliating recurrent cutaneous malignant melanoma.