Risk-adjustment in hepatobiliarypancreatic surgery

The accuracy of pre-operative (P)-POSSUM scoring and cardiopulmonary exercise testing in predicting morbidity and mortality after pancreatic and liver surgery: A systematic review

Background

Cardiopulmonary exercise-testing (CPET) and the (Portsmouth) Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity ((P)-POSSUM) are used as pre-operative risk stratification and audit tools in general surgery, however, both have been demonstrated to have limitations in major hepatopancreatobiliary (HPB) surgery.

Materials and methods

The aim of this review is to determine if CPET and (P)-POSSUM scoring systems accurately predict morbidity and mortality. Eligible articles were identified with an electronic database search. Analysis according to surgery type and tool used was performed.

Results

Twenty-five studies were included in the final review. POSSUM predicted morbidity demonstrated weighted O/E ratios of 0.75(95%CI0.57–0.97) in hepatic surgery and 0.85(95%CI0.8–0.9) in pancreatic surgery. P-POSSUM predicted mortality in pancreatic surgery demonstrated an O/E ratio of 0.75(95%CI0.27–2.13) and 0.94(95%CI0.57–1.55) in hepatic surgery. In both pancreatic and hepatic surgery an anaerobic threshold(AT) of between 9 0.5–11.5 ml/kg/min was predictive of post-operative complications, and in pancreatic surgery ventilatory equivalence of carbon dioxide(˙VE/˙VCO2) was predictive of 30-day mortality.

Conclusion

POSSUM demonstrates an overall lack of predictive fit for morbidity, whilst CPET variables provide some predictive power for post-operative outcomes. Development of a new HPB specific risk prediction tool would be beneficial; the combination of parameters from POSSUM and CPET, alongside HPB specific markers could overcome current limitations.

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Current pre-operative scoring for pancreatic and liver surgery is inaccurate.

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In pancreatic and liver surgery anaerobic threshold scores were predictive of complications.

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In pancreatic surgery ventilatory equivalence of carbon dioxide was predictive of mortality.

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P-POSSUM is inaccurate for predicting mortality and morbidity in pancreatic surgery.

Perioperative factors impacting intensive care outcomes following Whipple procedure: A retrospective study

Background and Aims

Whipple procedure is associated with perhaps the most perioperative morbidity and mortality amongst surgical procedures. Current data regarding their ICU profile and outcomes are lacking. Thus, in the present study, we aimed to determine perioperative factors affecting patient-centred outcomes following the Whipple procedure.

Methods

In a cohort of patients undergoing pylorus-sparing pancreaticoduodenectomies, we strove to determine perioperative variables that may impact outcomes. Unfavourable outcomes (composite of mortality, prolonged ICU stay of more than 14 days or ICU readmission) of patients who underwent the procedure were recorded and logistic regressions analysis of significant variables conducted.

Results

Around 68 patients recruited over a 20-month period which included 57 males (83.8%); mean age was 53.4(±11.2) with mean acute physiology and chronic health evaluation (APACHE) II score12.5 (±6.1). Nineteen patients remained intubated at the end of procedures (27.9%). Median ICU stay was 2 days (IQR 2-3). Unfavourable ICU outcomes were 14 in number (20.6%) and 2 (2.9%) hospital deaths occurred. Pulmonary complications occurred in 12 patients (17.7%) and non-pulmonary complications occurred in 41 patients (60.3%). In a multiple logistic regression analysis, the APACHE score 1.34 (1.09-1.64) and pulmonary complications 17.3 (2.1-145) were variables that were identified as predictors of unfavourable outcomes.

Conclusion

The APACHE II score may reliably predict adverse outcomes following Whipple procedure. Although non-pulmonary complications are common, pulmonary complications in these patients adversely impact patient outcomes.

Perioperative Mortality Prediction Using Possum in Patients with Gastrointestinal Tumors: Do Immunological Variables Affect Individual Predictive Mortality Risk?

The aim of this study was to evaluate whether the addition of immunological variables to the Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM) scoring system improves the predictability of postoperative mortality. One hundred and thirty-two consecutive patients who underwent moderate, major or major-plus elective surgical interventions for gastrointestinal tumors were scored using the POSSUM mortality risk analysis. Patients were placed in one of the two groups based on their POSSUM mortality rates which were either lower or higher than 5%. An additional 26 pre-operative and post-operative metabolic and immunological variables were measured and mortality-dependent variables were selected. Regression analysis with backward elimination of twelve pre-operative and post-operative variables correlating with POSSUM score revealed that post-operative neopterin, IL-6 and albumin were significantly dependent on the predicted mortality rates. According to these selected variables, the number of patients with a POSSUM predicted mortality rate higher than 5% increased from 64 to 88, but the percentage of the mean mortality decreased. Statistical differences between the original POSSUM and modified scoring system was highly significant (p<0.0001). The sensitivity and specificity of the modified scoring system was calculated to be 52.9% and 87.5%, respectively.

Complications of biliary-enteric anastomoses

INTRODUCTION Biliary-enteric anastomoses are performed for a range of indications and may result in early and late complications. The aim of this study was to assess the risk factors and management of anastomotic leak and stricture following biliary-enteric anastomosis. METHODS A retrospective analysis of the medical records of patients who underwent biliary-enteric anastomoses in a tertiary referral centre between 2000 and 2010 was performed. RESULTS Four hundred and sixty-two biliary-enteric anastomoses were performed. Of these, 347 (75%) were performed for malignant disease. Roux-en-Y hepaticojejunostomy or choledocho-jejunostomy were performed in 440 (95%) patients. Perioperative 30-day mortality was 6.5% (n=30). Seventeen patients had early bile leaks (3.7%) and 17 had late strictures (3.7%) at a median of 12 months. On univariable logistic regression analysis, younger age was a significant risk factor for biliary anastomotic leak. However, on multivariable analysis only biliary reconstruction following biliary injury (odds ratio [OR]=6.84; p=0.002) and anastomosis above the biliary confluence (OR=4.62; p=0.03) were significant. Younger age and biliary reconstruction following injury appeared to be significant risk factors for biliary strictures but multivariable analysis showed that only younger age was significant. CONCLUSIONS Biliary-enteric anastomoses have a low incidence of early and late complications. Biliary reconstruction following injury and a high anastomosis (above the confluence) are significant risk factors for anastomotic leak. Younger patients are significantly more likely to develop an anastomotic stricture over the longer term.

Improving surgical outcomes in pancreatic surgery with preoperative nutrition

The purposes of this study were (1) to describe the relationship between preoperative physical status and postoperative outcomes in patients undergoing Whipple resection, and (2) to determine if the use of specialized immunonutrition with IMPACT Advanced Recovery supplementation improved postoperative outcomes (pancreatic leak rate, length of stay, and postoperative complications) in patients undergoing Whipple resection. The trial was a case-controlled prospective pilot study that took place in an outpatient gastrointestinal surgical oncology office in an urban community hospital in the northeast United States. The study population consisted of nine patients undergoing Whipple surgery. Patients were given IMPACT Advanced Recovery supplementation 4 days prior to Whipple surgery. Prospective data were collected on all patients and then compared to national averages in terms of outcomes. Study approval was obtained from the Fairfield University Institutional Review Board (IRB), though IRB approval was not required by the study facility due to the fact that this was a pilot study. Consent was also not required for retrospective chart review. Patients with lower scores according to the American Society of Anesthesiologists Physical Status Classification System have a shorter operating time in the setting of preoperative nutrition. Patients in this study who received preoperative nutrition with IMPACT Advanced Recovery supplementation had outcomes comparable to the national average. This pilot study suggests that there is a need for a multi-institutional randomized study powered to further evaluate the effectiveness of preoperative nutrition in pancreatic surgery. The literature supports the fact that preoperative nutritional supplementation should be offered to patients undergoing Whipple surgery. Optimization of nutritional status can translate to decreased length of stay and cost savings.

Pre-operative cardiopulmonary exercise testing predicts adverse post-operative events and non-progression to adjuvant therapy after major pancreatic surgery

BACKGROUND

Surgery followed by chemotherapy is the primary modality of cure for patients with resectable pancreatic cancer but is associated with significant morbidity. The aim of the present study was to evaluate the role of cardiopulmonary exercise testing (CPET) in predicting post-operative adverse events and fitness for chemotherapy after major pancreatic surgery.

METHODS

Patients who underwent a pancreaticoduodenectomy or total pancreatectomy for pancreatic head lesions and had undergone pre-operative CPET were included in this retrospective study. Data on patient demographics, comorbidity and results of pre-operative evaluation were collected. Post-operative adverse events, hospital stay and receipt of adjuvant therapy were outcome measures.

RESULTS

One hundred patients were included. Patients with an anaerobic threshold less than 10 ml/kg/min had a significantly greater incidence of a post-operative pancreatic fistula [International Study Group for Pancreatic Surgery (ISGPS) Grades A-C, 35.4% versus 16%, P = 0.028] and major intra-abdominal abscesses [Clavien-Dindo (CD) Grades III-V, 22.4% versus 7.8%, P = 0.042] and were less likely to receive adjuvant therapy [hazard ratio (HR) 6.30, 95% confidence interval (CI) 1.25-31.75, P = 0.026]. A low anaerobic threshold was also associated with a prolonged hospital stay (median 20 versus 14 days, P = 0.005) but not with other adverse events.

DISCUSSION

CPET predicts a post-operative pancreatic fistula, major intra-abdominal abscesses as well as length of hospital stay after major pancreatic surgery. Patients with a low anaerobic threshold are less likely to receive adjuvant therapy.

Effectiveness of non-cardiac preoperative testing in non-cardiac elective surgery: a systematic review

Elective surgery is usually preceded by preoperative diagnostics to minimize risk. The results are assumed to elicit preventive measures or even cancellation of surgery. Moreover, physicians perform preoperative tests as a baseline to detect subsequent changes. This systematic review aims to explore whether preoperative testing leads to changes in management or reduces perioperative mortality or morbidity in unselected patients undergoing elective, non-cardiac surgery. We systematically searched all relevant databases from January 2001 to February 2011 for studies investigating the relationship between preoperative diagnostics and perioperative outcome. Our methodology was based on the manual of the Ludwig Boltzmann Institute for Health Technology Assessment, the Scottish Intercollegiate Guidelines Network (SIGN) handbook, and the PRISMA statement for reporting systematic reviews. One hundred and one of the 25 281 publications retrieved met our inclusion criteria. Three test grid studies used a randomized controlled design and 98 studies used an observational design. The test grid studies show that in cataract surgery and ambulatory surgery, there are no significant differences between patients with indicated preoperative testing and no testing regarding perioperative outcome. The observational studies do not provide valid evidence that preoperative testing is beneficial in healthy adults undergoing non-cardiac surgery. There is no evidence derived from high-quality studies that supports routine preoperative testing in healthy adults undergoing non-cardiac surgery. Testing according to pathological findings in a patient's medical history or physical examination seems justified, although the evidence is scarce. High-quality studies, especially large randomized controlled trials, are needed to explore the effectiveness of indicated preoperative testing.

POSSUM and P-POSSUM as predictors of postoperative morbidity and mortality in patients undergoing hepato-biliary-pancreatic surgery: a meta-analysis

BACKGROUND

Physiologic and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) models are used extensively to predict postoperative morbidity and mortality in general surgery. The aim was to undertake the first meta-analysis of the predictive value of these models in patients undergoing hepato-biliary-pancreatic surgery.

METHODS

Eligible articles were identified by searches of electronic databases from 1991 to 2012. All data were specific to hepato-biliary-pancreatic surgery. Predictive value of morbidity and mortality were assessed by calculating weighted observed to expected (O/E) ratios. Subanalysis was also performed.

RESULTS

Sixteen studies were included in final review. The morbidity analysis included nine studies on POSSUM with a weighted O/E ratio of 0.78 [95 % confidence interval (CI) 0.68-0.88]. The mortality analysis included seven studies on POSSUM and nine studies on P-POSSUM (Portsmouth predictor equation for mortality). Weighted O/E ratios for mortality were 0.35 (95 % CI 0.17-0.54) for POSSUM and 0.95 (95 % CI 0.65-1.25) for P-POSSUM. POSSUM had more accuracy to predict morbidity after pancreatic surgery (O/E ratio 0.82; 95 % CI 0.72-0.92) than after hepatobiliary surgery (O/E ratio 0.66; 95 % CI 0.57-0.74), in large sample size studies (O/E ratio 0.90; 95 % CI 0.85-0.96) than in small sample size studies (O/E ratio 0.69; 95 % CI 0.59-0.79).

CONCLUSIONS

POSSUM overpredicted postoperative morbidity after hepato-biliary-pancreatic surgery. Predictive value of POSSUM to morbidity was affected by the type of surgery and the sample size of studies. Compared with POSSUM, P-POSSUM was more accurate for predicting postoperative mortality. Modifications to POSSUM and P-POSSUM are needed for audit in hepato-biliary-pancreatic surgery.

A systematic review of the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity and its Portsmouth modification as predictors of post-operative morbidity and mortality in patients undergoing pancreatic surgery

BACKGROUND

The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) model and its Portsmouth modification (P-POSSUM) are used extensively to predict postoperative mortality and morbidity in general surgery. The aim of this study was to undertake the first systematic review of the predictive value of these models in patients undergoing pancreatic surgery.

METHODS

Eligible articles were identified by searches of electronic databases for those published from 1991 to 2012. Two independent reviewers assessed each study against inclusion and exclusion criteria. All data were specific to pancreatic surgery. Predictive value of morbidity and mortality were assessed by calculating observed/expected ratios.

RESULTS

Nine studies were included in the final review. The morbidity analysis included 8 studies (1,734 patients) of POSSUM with a weighted observed/expected ratio of .85. The mortality analysis included 5 studies (936 patients) of POSSUM and 4 studies (716 patients) of P-POSSUM. Weighted observed/expected ratios for mortality were .35 for POSSUM and 1.39 for P-POSSUM.

CONCLUSIONS

POSSUM overpredicted postoperative morbidity in patients undergoing pancreatic surgery. Both POSSUM and P-POSSUM failed to offer significant predictive value for mortality in pancreatic surgery, and more data collection in large populations undergoing pancreatic surgery are needed.

A review of factors predicting perioperative death and early outcome in hepatopancreaticobiliary cancer surgery

OBJECTIVES

In the context of comparisons of surgical outcomes, risk adjustment is the retrospective adjustment of a provider's or a surgeon's results for case mix and/or hospital volume. It allows accurate, meaningful inter-provider comparison. It is therefore an essential component of any audit and quality improvement process. The aim of this study was to review the literature to identify those factors known to affect prognosis in hepatobiliary and pancreatic cancer surgery.

METHODS

PubMed was used to identify studies assessing risk in patients undergoing resection surgery, rather than bypass surgery, for hepatobiliary and pancreatic cancer.

RESULTS

In total, 63 and 68 papers, pertaining to 24 609 and 63 654 patients who underwent hepatic or pancreatic resection for malignancy, respectively, were identified. Overall, 22 generic preoperative factors predicting outcome on multivariate analysis, including demographics, blood results, preoperative biliary drainage and co-morbidities, were identified, with tumour characteristics proving disease-specific factors. Operative duration, transfusion, operative extent, vascular resection and additional intra-abdominal procedures were also found to be predictive of early outcome.

CONCLUSIONS

The development of a risk adjustment model will allow for the identification of those factors with most influence on early outcome and will thus identify potential targets for preoperative optimization and allow for the development of a multicentre risk prediction model.

Evaluation of POSSUM in predicting post-operative morbidity in patients undergoing pancreaticoduodenectomy

The Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM) is a predictive scoring system for post-operative morbidity. The present study assessed the value of POSSUM in predicting post-operative morbidity following pancreaticoduodenectomy (PD). POSSUM scores were prospectively calculated for 265 consecutive cases of PD performed between 2005 and 2007. Expected morbidity was estimated based on POSSUM scores and was compared with observed morbidity. Patients were also stratified into one of four groups based on their individual POSSUM scores and subsequent risk of morbidity. Mean expected morbidity was 43.81% (116 cases) and mean observed morbidity was 39.62% (105 cases) (no statistically significant difference). It is concluded that the POSSUM scoring system has high value for predicting the risk of morbidity in PD patients.

Application of Portsmouth modification of physiological and operative severity scoring system for enumeration of morbidity and mortality (P-POSSUM) in pancreatic surgery

BACKGROUND

Pancreatoduodenectomy (PD) is associated with high incidence of morbidity and mortality. We have applied P-POSSUM in predicting the incidence of outcome after PD to identify those who are at the highest risk of developing complications.

METHOD

A prospective database of 241 consecutive patients who had PD from January 2002 to September 2005 was retrospectively updated and analysed. P-POSSUM score was calculated for each patient and correlated with observed morbidity and mortality.

RESULTS

30 days mortality was 7.8% and morbidity was 44.8%. Mean physiological score was 16.07 +/- 3.30. Mean operative score was 13.67 +/- 3.42. Mean operative score rose to 20.28 +/- 2.52 for the complex major operation (p < 0.001) with 2 fold increase in morbidity and 3.5 fold increase in mortality. For groups of patients with a physiological score of (less than or equal to) 18, the O:P (observed to Predicted) morbidity ratio was 1.3-1.4 and, with a physiological score of >18, the O:P ratio was nearer to 1. Physiological score and white cell count were significant in a multivariate model.

CONCLUSION

P-POSSUM underestimated the mortality rate. While P-POSSUM analysis gave a truer prediction of morbidity, underestimation of morbidity and potential for systematic inaccuracy in prediction of complications at lower risk levels is a significant issue for pancreatic surgery.

Should Elective Surgery for Chronic Pancreatitis be Performed in High-Risk Patients?

As morbidity and mortality rates for pancreatic surgery have improved over the past decades, patients with major medical comorbidities have been considered for operative treatment. The influence of poor health status on operative morbidity in patients with chronic pancreatitis is evaluated in this study. The records of 313 consecutive patients who underwent pancreaticoduodenectomy (n = 78), distal pancreatectomy (n = 83), or lateral pancreaticojejunostomy (n = 152) for chronic pancreatitis were retrospectively reviewed and analyzed. Patients’ risk for adverse outcome resulting from overall health status was audited using age, comorbidities, and Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) physiological score. Univariate analysis showed that patient's age did not contribute to change in morbidity (odds ratio [OR] = 1.01, P = 0.59). The presence of cardiac disease but not other comorbidities increased adverse outcome affected the need for intensive care unit stay and length of hospital stay (morbidity: 29% vs. 51%, OR = 2.6, P = 0.003). POSSUM physiological score was associated with an increase in morbidity and mortality (morbidity: OR = 1.16, P = 0.001; mortality: OR = 1.49, P = 0.001), in particular intraabdominal abscesses. Multivariate analysis showed that the only variable independently correlating with perioperative complications was POSSUM physiological score. Single comorbidities do not independently influence outcome after operations for chronic pancreatitis. A combination of several comorbidities is associated with an increase in postoperative infectious morbidity and mortality. High-risk patients should not be excluded from operative treatment, but need to be closely selected on a case-by-case basis.