Selecting patients for acute normovolemic hemodilution during hepatic resection: a prospective randomized evaluation of nomogram-based allocation

A pre-operative scoring model to estimate the risk of blood transfusion over an ovarian cancer debulking surgery (BLOODS score): a Memorial Sloan Kettering Cancer Center Team Ovary study

OBJECTIVES

To develop a pre-operative tool to estimate the risk of peri-operative packed red blood cell transfusion in primary debulking surgery.

METHODS

We retrospectively reviewed an institutional database to identify patients who underwent primary debulking surgery for ovarian cancer at a single center between January 1, 2001 and May 31, 2019. Receiver operating characteristic curve and area under the receiver operating characteristic curve (AUC) were calculated. Five-fold cross-validation was applied to the multivariate model. Significant variables were assigned a 'BLOODS' (BLood transfusion Over an Ovarian cancer Debulking Surgery) score of +1 if present. A total BLOODS score was calculated for each patient, and the odds of receiving a transfusion was determined for each score.

RESULTS

Overall, 1566 patients met eligibility criteria; 800 (51%) underwent a peri-operative blood transfusion. Odds ratios (OR) were statistically significant for American Society of Anesthesiologists scores of 3 and 4 (OR 1.34, 95% confidence interval (95% CI) 1.09 to 1.63), pre-operative levels of cancer antigen 125 (CA125) (OR 2.43, 95% CI 1.98 to 2.99), platelets (OR 1.59, 95% CI 1.45 to 1.74), obesity (OR 0.76, 95% CI 0.60 to 0.96), presence of carcinomatosis (OR 2.45, 95% CI 1.93 to 3.11), bulky upper abdominal disease (OR 2.86, 95% CI 2.32 to 3.54), pre-operative serum albumin level (OR 0.31, 95% CI 0.24 to 0.40), and pre-operative hemoglobin level (OR 0.56, 95% CI 0.51 to 0.61). The corrected AUC was 0.748 (95% CI 0.693 to 0.804). BLOODS scores of 0 and 5 corresponded to 11% and 73% odds, respectively, of receiving a peri-operative blood transfusion.

CONCLUSIONS

We developed a universal pre-operative scoring system, the BLOODS score, to help identify patients with ovarian cancer who would benefit from surgical planning and blood-saving techniques. The BLOODS score was directly proportional to the American Society of Anesthesiologists score, presence of upper abdominal disease, carcinomatosis, CA125 level, and platelets level. We believe this model can help physicians with surgical planning and can benefit patient outcomes.

Anesthesia for Patients with Anemia

Anemia is a common and often ignored condition in surgical patients. Anemia is usually multifactorial and iron deficiency and inflammation are commonly involved. An exacerbating factor in surgical patients is iatrogenic blood loss. Anemia has been repeatedly shown to be an independent predictor of worse outcomes. Patient blood management (PBM) provides a multimodality framework for prevention and management of anemia and related risk factors. The key strategies in PBM include support of hematopoiesis and improving hemoglobin level, optimizing coagulation and hemostasis, use of interdisciplinary blood conservation modalities, and patient-centered decision making throughout the course of care.

Three-point transfusion risk score in hepatectomy

BACKGROUND

Perioperative red blood cell transfusions are required in up to 23 per cent of patients undergoing hepatectomy. Previous research has developed three transfusion risk scores to assess risk of perioperative red blood cell transfusion. Here, the performance of these transfusion risk scores was evaluated in a multicentre cohort of patients who underwent hepatectomy and compared with that of a simplified transfusion risk score.

METHODS

A database of patients undergoing hepatectomy at four specialized centres between 2008 and 2012 was developed. External validity was assessed by discrimination and calibration. Discrimination was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC). Calibration was evaluated by the degree of agreement between predicted and actual red blood cell transfusion probabilities. A simplified transfusion risk score using variables common to the three models was created, and discrimination and calibration were evaluated.

RESULTS

There were 1287 patients included in this study, with 341 (26·5 per cent) receiving a red blood cell transfusion. Discriminative ability was similar between the three transfusion risk scores, with AUCs of 0·66-0·68 and good calibration. A new three-point risk score was developed based on factors present in all models: haemoglobin 12·5 g/dl or less, primary liver malignancy and major resection (at least 4 segments). Discriminative ability and calibration of the three-point model were similar to those of the three existing models, with an AUC of 0·66.

CONCLUSION

The three-point transfusion risk score simplifies assessment of perioperative transfusion risk in hepatectomy without sacrificing predictive ability.

Methods to decrease blood loss during liver resection: a network meta-analysis

BACKGROUND

Liver resection is a major surgery with significant mortality and morbidity. Specialists have tested various methods in attempts to limit blood loss, transfusion requirements, and morbidity during elective liver resection. These methods include different approaches (anterior versus conventional approach), use of autologous blood donation, cardiopulmonary interventions such as hypoventilation, low central venous pressure, different methods of parenchymal transection, different methods of management of the raw surface of the liver, different methods of vascular occlusion, and different pharmacological interventions. A surgeon typically uses only one of the methods from each of these seven categories. The optimal method to decrease blood loss and transfusion requirements in people undergoing liver resection is unknown.

OBJECTIVES

To assess the effects of different interventions for decreasing blood loss and blood transfusion requirements during elective liver resection.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and Science Citation Index Expanded to September 2015 to identify randomised clinical trials. We also searched trial registers and handsearched the references lists of identified trials.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) comparing different methods of decreasing blood loss and blood transfusion requirements in people undergoing liver resection.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and collected data. We assessed the risk of bias using Cochrane domains. We conducted a Bayesian network meta-analysis using the Markov chain Monte Carlo method in WinBUGS 1.4, following the guidelines of the National Institute for Health and Care Excellence Decision Support Unit guidance documents. We calculated the odds ratios (OR) with 95% credible intervals (CrI) for the binary outcomes, mean differences (MD) with 95% CrI for continuous outcomes, and rate ratios with 95% CrI for count outcomes, using a fixed-effect model or random-effects model according to model-fit. We assessed the evidence with GRADE.

MAIN RESULTS

We identified 67 randomised clinical trials involving a total of 6197 participants. All the trials were at high risk of bias. A total of 5771 participants from 64 trials provided data for one or more outcomes included in this review. There was no evidence of differences in most of the comparisons, and where there was, these differences were in single trials, mostly of small sample size. We summarise only the evidence that was available in more than one trial below. Of the primary outcomes, the only one with evidence of a difference from more than one trial under the pair-wise comparison was in the number of adverse events (complications), which was higher with radiofrequency dissecting sealer than with the clamp-crush method (rate ratio 1.85, 95% CrI 1.07 to 3.26; 250 participants; 3 studies; very low-quality evidence). Among the secondary outcomes, the only differences we found from more than one trial under the pair-wise comparison were the following: blood transfusion (proportion) was higher in the low central venous pressure group than in the acute normovolemic haemodilution plus low central venous pressure group (OR 3.19, 95% CrI 1.56 to 6.95; 208 participants; 2 studies; low-quality evidence); blood transfusion quantity (red blood cells) was lower in the fibrin sealant group than in the control (MD -0.53 units, 95% CrI -1.00 to -0.07; 122 participants; 2; very low-quality evidence); blood transfusion quantity (fresh frozen plasma) was higher in the oxidised cellulose group than in the fibrin sealant group (MD 0.53 units, 95% CrI 0.36 to 0.71; 80 participants; 2 studies; very low-quality evidence); blood loss (MD -0.34 L, 95% CrI -0.46 to -0.22; 237 participants; 4 studies; very low-quality evidence), total hospital stay (MD -2.42 days, 95% CrI -3.91 to -0.94; 197 participants; 3 studies; very low-quality evidence), and operating time (MD -15.32 minutes, 95% CrI -29.03 to -1.69; 192 participants; 4 studies; very low-quality evidence) were lower with low central venous pressure than with control. For the other comparisons, the evidence for difference was either based on single small trials or there was no evidence of differences. None of the trials reported health-related quality of life or time needed to return to work.

AUTHORS' CONCLUSIONS

Paucity of data meant that we could not assess transitivity assumptions and inconsistency for most analyses. When direct and indirect comparisons were available, network meta-analysis provided additional effect estimates for comparisons where there were no direct comparisons. However, the paucity of data decreases the confidence in the results of the network meta-analysis. Low-quality evidence suggests that liver resection using a radiofrequency dissecting sealer may be associated with more adverse events than with the clamp-crush method. Low-quality evidence also suggests that the proportion of people requiring a blood transfusion is higher with low central venous pressure than with acute normovolemic haemodilution plus low central venous pressure; very low-quality evidence suggests that blood transfusion quantity (red blood cells) was lower with fibrin sealant than control; blood transfusion quantity (fresh frozen plasma) was higher with oxidised cellulose than with fibrin sealant; and blood loss, total hospital stay, and operating time were lower with low central venous pressure than with control. There is no evidence to suggest that using special equipment for liver resection is of any benefit in decreasing the mortality, morbidity, or blood transfusion requirements (very low-quality evidence). Radiofrequency dissecting sealer should not be used outside the clinical trial setting since there is low-quality evidence for increased harm without any evidence of benefits. In addition, it should be noted that the sample size was small and the credible intervals were wide, and we cannot rule out considerable benefit or harm with a specific method of liver resection.

A decision model and cost analysis of intra-operative cell salvage during hepatic resection

BACKGROUND

Intraoperative cell salvage (ICS) can reduce allogeneic transfusions but with notable direct costs. This study assessed whether routine use of ICS is cost minimizing in hepatectomy and defines a subpopulation of patients where ICS is most cost minimizing based on patient transfusion risk.

METHODS

A decision model from a health systems perspective was developed to examine adoption and non-adoption of ICS use for hepatectomy. A prospectively maintained database of hepatectomy patients provided data to populate the model. Probabilistic sensitivity analysis was used to determine the probability of ICS being cost-minimizing at specified transfusion risks. One-way sensitivity analysis was used to identify factors most relevant to institutions considering adoption of ICS for hepatectomies.

RESULTS

In the base case analysis (transfusion risk of 28.8%) the probability that routine utilization of ICS is cost-minimizing is 64%. The probability that ICS is cost-minimizing exceeds 50% if the patient transfusion risk exceeds 25%. The model was most sensitive to patient transfusion risk, variation in costs of allogeneic blood, and number of appropriate cases the device could be used for.

CONCLUSIONS

ICS is cost-minimizing for routine use in liver resection, particularly when used for patients with a risk of transfusion of 25% or greater.

A Conceptual Technique for Laparoscopic Right Hepatectomy Based on Facts and Oncologic Principles: The Caudal Approach

OBJECTIVE

To evaluate a new conceptual technique of laparoscopic right hepatectomy.

BACKGROUND

Despite significant improvements in surgical care in the last decades, morbidity is still high after major hepatectomy. Blood loss and transfusions are known to significantly increase the risk of postoperative complications and cancer recurrence after liver resection. A laparoscopic approach may improve perioperative outcomes in these cases, but data in literature are limited and the surgical technique is not yet standardized.

METHODS

A new conceptual technique of right hepatectomy was designed using evidence-based facts and oncologic rules: laparoscopy with pneumoperitoneum, low central venous pressure, intermittent pedicle clamping, anterior approach without mobilization, and parenchymal section with ultrasonic dissector. Thirty patients were prospectively enrolled between October 2011 and September 2013. Primary endpoint was intraoperative blood loss.

RESULTS

Eighty percent of patients underwent surgery for malignant disease and cirrhosis was present in 11 patients. Benign lesions accounted for 13% of indications, whereas living liver donation was performed in 2 cases. Median blood loss was 100 mL (50-700) and transfusion rate was 7%. Five patients (16.6%) required conversion to laparotomy, including 2 using hybrid technique. The median operative time was 360 minutes (210-510). R0 resection rate was 87% (21/24). Postoperative morbidity rate was 23% (7/30) with 8 complications including 6 Clavien III-IV. No respiratory complication occurred. The median hospital stay was 8 days. No patient died.

CONCLUSIONS

This study showed that several evidence-based facts could be combined to define a new conceptual technique of laparoscopic right hepatectomy allowing for low blood loss and morbidity.

Nomograms in oncology: more than meets the eye

Nomograms are widely used as prognostic devices in oncology and medicine. With the ability to generate an individual probability of a clinical event by integrating diverse prognostic and determinant variables, nomograms meet our desire for biologically and clinically integrated models and fulfill our drive towards personalised medicine. Rapid computation through user-friendly digital interfaces, together with increased accuracy, and more easily understood prognoses compared with conventional staging, allow for seamless incorporation of nomogram-derived prognosis to aid clinical decision making. This has led to the appearance of many nomograms on the internet and in medical journals, and an increase in nomogram use by patients and physicians alike. However, the statistical foundations of nomogram construction, their precise interpretation, and evidence supporting their use are generally misunderstood. This issue is leading to an under-appreciation of the inherent uncertainties regarding nomogram use. We provide a systematic, practical approach to evaluating and comprehending nomogram-derived prognoses, with particular emphasis on clarifying common misconceptions and highlighting limitations.

Renal function after low central venous pressure-assisted liver resection: assessment of 2116 cases

OBJECTIVES

Low central venous pressure (LCVP)-assisted hepatectomy is associated with decreased blood loss and lower transfusion rates. Concerns about its impact on renal function have prevented widespread application. This study was conducted to review the dynamics of renal function after LCVP-assisted hepatectomy.

METHODS

A retrospective analysis of a prospective surgical database was carried out. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) equation. The RIFLE (risk-injury-failure-loss-end-stage) criteria were used to define postoperative biochemical acute kidney injury (bAKI). Occurrences of clinically relevant AKI (cAKI) were identified in the study center postoperative database.

RESULTS

During the period 2003-2012, 2116 LCVP-assisted hepatectomies were performed. The median patient age was 61 years [interquartile range (IQR): 51-70 years] and 51% of patients were male. The median number of resected segments was two; resections involved from one to four segments. Median estimated blood loss was 300 ml (IQR: 200-600 ml). Rates of morbidity and 90-day mortality were 21% and 2%, respectively. Low baseline eGFR (<90 ml/min) was seen in 84% of patients; 29% of patients had eGFR of <30 ml/min. Postoperative bAKI was seen in 17% (n = 350) of patients. Biochemical AKI with low eGFR was seen in 336 patients, representing 16% of the whole cohort; 13% of patients had been at risk, 2% experienced injury and 1% experienced failure. Kidney function had normalized at discharge in 159 of these patients. Nine patients (<1%) developed postoperative cAKI.

CONCLUSIONS

The majority of patients in the study cohort had low baseline eGFR. Biochemical alterations in eGFR are transient in the vast majority of patients after LCVP-assisted hepatectomy and their clinical impact is limited. The present data suggest that clinically relevant renal dysfunction is a very uncommon event in patients undergoing LCVP-assisted liver resection.