The complication-overall survival (CompOS) risk tool predicts risk of a severe postoperative complications relative to long-term survival among patients with primary liver cancer

BACKGROUND

This study aimed to develop a tool based on preoperative factors to predict the risk of perioperative complications based on the Comprehensive Complication Index (CCI) and long-term survival outcomes after liver resection for primary liver cancer.

METHODS

Patients with hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC) undergoing curative-intent hepatectomy between 1990 and 2020 were identified using a multi-institutional international database.

RESULTS

Among 1411 patients who underwent curative-intent hepatic resection (HCC: 997, 70.7%; ICC: 414, 29.3%), median patient age was 66.0 years (IQR, 57.0-73.0), and most patients were male (n = 1001, 70.9%). In the postoperative setting, 699 patients (49.5%) experienced a complication; moreover, 112 patients (7.9%) had major complications. Although most patients had a favorable risk complication-overall survival (CompOS) profile (CCI score > 40 risk of <30% and median survival of >5 years: n = 778, 55.1%), 553 patients (39.2%) had an intermediate-risk profile, and 80 patients (5.7%) had a very unfavorable risk profile (CCI score > 40 risk of ≥30% and/or median survival of ≤1.5 years). The areas under the curve of the test and validation cohorts were 0.73 and 0.76, respectively.

CONCLUSION

The CompOS risk model accurately stratified patients relative to short- and long-term risks, identifying a subset of patients at a high risk of major complications and poor overall survival.

Evaluation of the usefulness of the Clavien-Dindo classification of surgical complications

The Clavien-Dindo (CD) classification is widely used in the reporting of surgical complications in scientific literature. It groups complications based on the level of intervention required to resolve them, and benefits from simplicity and ease of use, both of which contribute its to high inter-rater reliability. It has been validated for use in many specialties due to strong correlation with key outcome measures including length of stay, postsurgical quality of life and case-related renumeration. Limitations of the classification include concerns over differentiating grade III and IV complications and not classifying intraoperative complications. The Comprehensive Complication Index is an adaptation of the CD classification which generates a morbidity score from 0 to 100. It has been proposed as a more effective method of assessing the morbidity burden of surgical procedures. However, it remains less popular as calculations of morbidity are complicated and time-consuming. In recent years there have been suggestions of adaptations to the CD classification such as the Clavien-Dindo-Sink classification, while in some specialties, completely new classifications have been proposed due to evidence the CD classification is not reliable. Similarly, the Surgical Expertise and Validity Evaluation project aims to determine benchmarks against which surgeons may compare their own practice.

Surgical outcome improvement by shared decision-making: value of a preoperative multidisciplinary target clinic for the elderly in colorectal surgery

PURPOSE

Frailty and comorbidities increase the risk of postoperative complications and raise treatment costs. Perioperative optimisation is shown to improve surgical outcomes for the elderly. The aim of this study was to assess the impact of introducing a multidisciplinary preoperative clinic for older patients (Colchester Older Persons' Evaluation for Surgery (COPES) clinic) undergoing major colorectal surgery.

METHODS

This 5-year single centre study included patients >65 years with ≥3 comorbidities undergoing major colorectal surgery. From October 2018, patients with these characteristics were evaluated and optimised in the COPES clinic by a geriatrician and an anaesthetist. Outcomes were compared to high-risk patients operated on prior to COPES (pre-COPES group). The primary outcomes were postoperative morbidity at discharge and 6 months measured by the Comprehensive Complication Index. Patients were matched on age and number of comorbidities.

RESULTS

A total of 54 patients were enrolled in the pre-COPES and 18 in the COPES group. After matching, the results were comparable for both groups. The length of stay was shorter in the COPES group and the recurrence rate was higher; however, it did not reach statistical significance in both findings.

CONCLUSION

This clinic intends to improve treatment quality, placing emphasis on shared decision-making. More focus should be put on patient-reported outcomes and experiences. Especially for elderly patients, quality of life and maintaining independence are often their priority. To determine the true value of a preoperative multidisciplinary clinic targeting elderly comorbid patients, a prospective study with larger cohort is needed, focusing not only on objective outcomes but also on patient-reported outcomes.

Nephrometry and cumulative morbidity after partial nephrectomy: A standardized assessment of complications in the context of PADUA and R.E.N.A.L. scores

BACKGROUND

Nephrometry scores aid in clinical decision-making, yet evidence is scarce regarding their impact on cumulative morbidity following partial nephrectomy (PN).

PATIENTS AND METHODS

Retrospective, monocentric study of 122 patients with suspicious renal masses undergoing open or robot-assisted PN between January 2019 and August 2020. Morbidity assessment followed European Association of Urology guidelines on complication reporting. 30-d complications were extracted using a PN-specific catalog, were graded by the Clavien-Dindo classification (CDC), and Comprehensive Complication Index (CCI®) values were calculated. The impact of nephrometry on cumulative morbidity was evaluated by (1) comparing morbidity estimates between Preoperative Aspects and Dimensions Used for an Anatomical (PADUA)/R.E.N.A.L. complexity groups, (2) by Pearson's correlation between nephrometry scores and CCI®, and (3) by multivariable regression models using any 30-d complication and 30-d CCI® as endpoints.

RESULTS

Of 122 patients, 101 (83%) underwent open and 21 (17%) robot-assisted PN. Median PADUA and R.E.N.A.L. scores were 9 (interquartile range, IQR 8-10) and 8 (IQR 6-9), respectively. Of 218 complications in 92 patients (75%), the majority was classified as minor (CDC grade ≤IIIa). Median 30-d CCI® was 8.7 (IQR 0.50-15). There was a small positive correlation between PADUA or R.E.N.A.L. score with CCI® (all P ≤ 0.026), explaining 4.7% and 4.1% of the variation in CCI®, respectively. After adjustment, nephrometry scores were associated with any 30-d complication and the CCI® (all P ≤ 0.011). PADUA and R.E.N.A.L. high complexity tumors were positively associated with both morbidity endpoints compared to low complexity tumors (all P ≤ 0.041).

CONCLUSIONS

At a referral center, PN may be safely performed, even if morbidity assessment follows a strict protocol. Nephrometry risk classification does only marginally translate into clinical relevant differences regarding short-term complications. Thus, nephron-sparing surgery should not be withheld from patients with high complexity renal masses.

Urinary Diversion With or Without Concomitant Cystectomy for Benign Conditions: A Comparative Morbidity Assessment According to the Updated European Association of Urology Guidelines on Reporting and Grading of Complications

BACKGROUND

Evidence is scarce on morbidity after urinary diversion ± cystectomy as treatment for benign bladder indications.

OBJECTIVE

To conduct a morbidity assessment and to evaluate the impact of concomitant subtrigonal cystectomy (SC) versus urinary diversion (UD) alone.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective study of 97 patients with benign bladder conditions between 2009 and 2017.

INTERVENTION

Open UD and/or concomitant SC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Data for 30-d complications were extracted using a procedure-specific catalog and were graded according to the Clavien-Dindo classification (CDC), and Comprehensive Complication Index (CCI) values were calculated. Traditional morbidity endpoints focused on the comparative morbidity of UD + SC versus UD alone. Multivariable regressions were computed to evaluate the impact of SC versus UD alone on cumulative morbidity. Subgroup analyses were repeated for patients with previous irradiation.

RESULTS AND LIMITATIONS

Of 97 patients, 46 (47%) underwent UD + SC and 51 (53%) underwent UD alone. Forty-nine patients (51%) had a history of abdominopelvic radiotherapy. Overall, 69 (71%) patients underwent continent UD and 26 (27%) underwent a Mitrofanoff procedure. We registered 390 complications in 97 (100%) patients, the majority of which were classified as minor (CDC grade ≤IIIa; 93%). Overall, three patients (3.1%) were readmitted and no patient died within 30 d. On multivariable analyses, neither concomitant SC nor previous radiotherapy was associated with higher cumulative morbidity (all p = 0.2). Similarly, concomitant SC was not predictive of a higher complication burden in the irradiation subgroup (all p ≥ 0.05). Limitations include heterogeneity for indications and a lack of information on the radiation dose and field.

CONCLUSIONS

In a high-volume referral center, neither SC nor abdominopelvic radiotherapy increased perioperative cumulative morbidity for patients with benign bladder conditions undergoing UD. This is particularly relevant for patients who would benefit from concomitant SC to avert adverse sequelae related to the retained bladder.

PATIENT SUMMARY

Urinary diversion (UD) is a surgical procedure to create a new way for urine to exit the body. We found that among patients undergoing UD for benign bladder conditions, those who also have their bladder removed and patients who have received previous radiotherapy do not experience more complications.

Impact of early quantitative morbidity on 1-year outcomes in coronary artery bypass graft surgery

OBJECTIVES

We applied the Clavien-Dindo Complications Classification (CDCC) and the Comprehensive Complication Index (CCI) to the CORONARY trial to assess whether quantitative early morbidity affects outcomes at 1 year.

METHODS

All postoperative hospitalization and 30-day follow-up complications were assigned a CDCC grade. CCI were calculated for all patients (n = 4752). Kaplan-Meier analysis examined 1-year mortality and 1-year co-primary outcome (i.e. death, non-fatal stroke, non-fatal myocardial infarction, new-onset renal failure requiring dialysis or repeat coronary revascularization) by CDCC grade. Multivariable logistic regression evaluated the predictive value of CCI for both outcomes.

RESULTS

For off-pump and on-pump coronary artery bypass graft surgery, median CDCC were 1 [interquartile range: 0, 2] and 2 [1, 2] (P < 0.001), while median CCI were 8.7 [0, 22.6] and 20.9 [8.7, 29.6], respectively (P < 0.001). In on-pump, there were more grade I and grade II complications, particularly grade I and II transfusions (P < 0.001) and grade I acute kidney injury (P = 0.039), and more grade IVa respiratory failures (P = 0.047). Patients with ≥IIIa complications had greater cumulative 1-year mortality (P < 0.001). The median CCI was 8.7 [0, 22.6] in patients who survived and 22.6 [8.7, 44.3] in patients who died at 1 year (P < 0.001). The CCI remained an independent risk factor for 1-year mortality and 1-year co-primary outcome after multivariable adjustment (P < 0.001).

CONCLUSIONS

On-pump coronary artery bypass graft surgery had a greater number of complications in the early postoperative period, likely driven by transfusions, respiratory outcomes and acute kidney injury. This affects 1-year outcomes. Similar analyses have not yet been used to compare both techniques and could prove useful to quantify procedural morbidity.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov/ct2/show/NCT00463294; Unique Identifier: NCT00463294.

The Comprehensive Complication Index. Proposed modification to improve estimates of perioperative morbidity after radical cystectomy. A pilot study

Introduction

The aim of this article was to compare the 30-day morbidity after radical cystectomy comparing the prevalent Clavien-Dindo Classification (CDC) and the novel Comprehensive Complication Index (CCI). Additionally, we evaluated the correlation between particular clinical features and the severity of perioperative morbidity.

Material and methods

A total of 42 patients were included into the study (33 men and 9 women) who underwent open radical cystectomy (RC) with bilateral lymphadenectomy for bladder cancer. The selection of complications was based on groundbreaking research on morbidity after RC. The assessment of perioperative complications was performed using the CDC and then the CCI.

Results

The CCI was found to be a significant upgrade in capturing cumulative morbidity in comparison to the CDC when used as the only evaluational tool.

Conclusions

Using only the CDC may underestimate the severity of perioperative complications. Unfavorable clinical features e.g. older age, chronic kidney disease (CKD), persistent nodal (pN+) disease, prior abdominal and pelvic surgeries as well as smoking are of significant importance for the increase of the severity of perioperative complications.

Aggressive Laparoscopic Cholecystectomy in Accordance with the Tokyo Guideline 2018

Objectives:

The Tokyo Guidelines 2018 have been widely adopted since their publication. However, the few reports on clinical outcomes following laparoscopic cholecystectomy have not taken into account the severity of the acute cholecystitis and the patient’s general condition, as estimated by the Charlson comorbidity index. This study aimed to assess the relationships between severity, Charlson comorbidity index, and clinical outcomes subsequent to laparoscopic cholecystectomy.

Methods:

We extracted the retrospective data for 370 Japanese patients who underwent emergency or scheduled early laparoscopic cholecystectomy within 72 hours from onset between February 2015 and August 2018. We compared postoperative factors in relationship to severity (grade I versus grade II/III). Then, we made a similar comparison between those with low (< 4) and high Charlson comorbidity index (≥ 4).

Results:

According to the Tokyo guideline 2018 levels of severity, there were 282 (76.2%), 61 (16.5%), and 27 (7.3%) patients in grades I, II, and III, respectively. With regards to surgical outcomes, the mean operating time was 62.3 minutes and the mean blood loss was 24.4 mL. The mean hospital stay was 3.6 days, with no mortalities. Blood loss was the only factor affected by severity (20.9 mL versus 60.1 mL, P = 0.0164), and operating time was the only factor affected by high Charlson comorbidity index (53.4 versus 67.8 minutes, P = 0.0153).

Conclusion:

Our aggressive strategy is acceptable, and severity and Charlson comorbidity index are not critical factors suggesting the disqualification of early laparoscopic cholecystectomy in patients with any grade acute cholecystitis.

Comparison of the Clavien-Dindo and Comprehensive Complication Index systems for grading of surgical complications after colorectal resections

INTRODUCTION

Postoperative complications are associated with prolonged hospital stay and a rise in costs of treatment. The Comprehensive Complication Index (CCI) was developed as a scoring system that does not only take the most severe complication into account but all complications after surgery. Our aim was to compare the Clavien-Dindo scoring system with the CCI in predicting length of hospital stay (LOHS) and in-hospital costs after colorectal resections.

METHODS

Complications occurring after surgical procedures, performed between October 2012 and September 2013, were prospectively recorded. During this period 164 patients developed complication(s). Only patients that underwent a colorectal resection were included. Multivariable linear regression analysis was performed to find independent predictors of in-hospital costs and LOHS.

RESULTS

64 patients (age (range): 69 (10-91) years, M/F: 36/28) were retained. 46 (71.9%) patients had a Clavien-Dindo score ≥ IIIb. Median (IQR) CCI was 40 (30.2-53.9). Mean (±SD) in-hospitals costs for all patients were €12,920 ± €10,229. The adjusted difference (95% CI, p-value) in in-hospital costs for minor and major (Clavien-Dindo ≥ IIIb) complications was 10,021 (€4283 to €15,759, p = 0.001). A 10 point increase in CCI increased in-hospital costs by €2040. Multivariable analysis retained CCI > 40 as the only independent risk factor for increased in-hospital costs (Standard Beta Coeffic (p-value): 8063 (p = 0.022).

CONCLUSION

CCI is a better predictor of in-hospital costs than Clavien-Dindo score to classify complications after colorectal resections, as it captures all complications. Further research is warranted to extrapolate our findings to other sub-specialities of surgery.

Clinical Validation of the Comprehensive Complication Index in Colon Cancer Surgery

(1) Introduction: To date, the sensitivity of the Comprehensive Complication Index (CCI) in a homogeneous cohort of colonic resections for oncologic purposes has not been reported. The present study aims to compare the CCI with the conventional Clavien-Dindo classification (CDC) in colon cancer patients. (2) Methods: The clinical data of patients submitted to an elective colectomy for adenocarcinoma were retrieved from a prospectively maintained database. Postoperative complications and length of stay were reviewed, and CDC and CCI scores were calculated for each patient. The association of the CCI and the CDC with the length of stay, prolongation of stay and readmission rate were assessed and compared. (3) Results: The overall postoperative morbidity was 26.9%. In particular, 157 (20.4%) patients had more than one complication. A strong correlation between the two scoring systems was observed (r = 99.4%; 95%CI: 99.3-99.5%). In multivariate analysis, CCI had a higher predictive ability for all endpoints. Regarding subgroup analysis, the difference between the CCI and CDC was progressively increased when evaluating outcome measures in complicated and multi-complicated patients. (4) Conclusion: Both scoring systems adequately report the overall burden of postoperative complications. The CCI showed a greater ability than the CDC to predict hospital stay, particularly in patients with multiple postoperative complications.

Colorectal cancer surgery in selected nonagenarians is relatively safe and it is associated with a good long-term survival: an observational study

Background

Advanced age is a risk factor for colorectal cancer, and very elderly patients often need to be surgically treated. This study aimed to analyze the outcomes of a cohort of nonagenarian patients operated on for colorectal cancer.

Methods

Observational study conducted on a cohort of 40 nonagenarian patients, who were treated surgically for colorectal cancer between 2000 and 2018 in our institution. Clinical data, ASA score, Charlson Comorbidity Index, Surgical Mortality Probability Model, tumor characteristics, and nature and technical features of the surgical procedure, were recorded. The Comprehensive Complication Index (CCI) and survival time after the procedure were recorded as outcome variables. Univariate and multivariate analyses were performed in order to define risk factors for postoperative complications and long-term survival.

Results

Out of the 40 patients, 13 (32.5%) were men, 27 (67.5%) women, and mean age 91.6 years (SD ± 1.5). In 24 patients (60%), surgery was elective, and in 16 patients (40%), surgery was emergent. Curative surgery with intestinal resection was performed in 34 patients (85%). In 22 patients (55%), intestinal continuity was restored by performing an anastomosis. The median CCI was 22.6 (IRQ 0.0–42.6). Operative mortality was 10% (4 patients). Cumulative survival at 1, 3, and 5 years was 70%, 47%, and 29%, respectively. In multivariate analysis, only the need for transfusion remained as an independent prognostic factor for complications (p = 0.021) and TNM tumor stage as a significant predictor of survival (HR 3.0, CI95% 1.3–7.2).

Conclusions

Colorectal cancer surgery is relatively safe in selected nonagenarian patients and may achieve long-term survival.

A single-center prospective observational study on the effect of trimodal prehabilitation in colorectal surgery

INTRODUCTION

A trimodal prehabilitation protocol was designed with the aim to evaluate whether it contributes to reducing postoperative morbidity, to evaluate the effect of prehabilitation on overall hospital stay, and to analyze the evolution of functional capacity before and after surgery.

METHODS

A single-center observational study of patients with colorectal cancer who underwent surgery with curative intent after a trimodal prehabilitation protocol. We collected data for postoperative morbidity according to the Comprehensive Complication Index and hospital stay, which were compared with a historical matrix. Functional capacity data were also collected before and after the application of the prehabilitation protocol.

RESULTS

Compared to the historical population, the overall Comprehensive Complication Index was reduced from 13.2 to 11.5, which was statistically significant. Analyzed by morbidity type, all decreased in percentage, although without achieving significance (surgical site infection from 11.7% to 8.4%, nosocomial infection 15.8 to 10% and medical morbidity 8.6% to 4.2%). The overall hospital stay went from 6 to 4 days, and the decrease in the percentage of patients who prepared at home was statistically significant in both cases.

CONCLUSIONS

Trimodal prehabilitation can contribute to lowering the postoperative morbidity and overall hospital stay of patients undergoing colorectal cancer surgery.

Postoperative complications in gastrointestinal surgery: A “hidden” basic quality indicator

Postoperative complications represent a basic quality indicator for measuring outcomes at surgical units. At present, however, they are not systematically measured in all surgical procedures. A more accurate assessment of their impact could help to evaluate the real morbidity associated with different surgical interventions, establish measures for improvement, increase efficiency and identify benchmarking services. The Clavien-Dindo Classification is the most widely used system worldwide for assessing postoperative complications. However, the postoperative period is summarized by the most serious complication without taking into account others of lesser magnitude. Recently, two new scoring systems have emerged, the Comprehensive Complication Index and the Complication Severity Score, which include all postoperative complications and quantify them from 0 (no complications) to 100 (patient’s death), These allow the comparison of results. It is important to train surgical staff to report and classify complications and to record 90-d morbidity rates in all patients. Comparisons with other services must take into account patient comorbidities and the complexity of the particular surgical procedure. To avoid subjectivity and bias, external audits are necessary. In addition, ensuring transparency in the reporting of the results is an urgent obligation.

The Comprehensive Complication Index CCI: A proposed modification to optimize short-term complication reporting after cystectomy and urinary diversion

OBJECTIVE

To optimize complication reporting in patients undergoing cystectomy and urinary diversion (UD) using the Comprehensive Complication Index (CCI). The original CCI ranging from 0 (no complications) to 100 (death) integrates all complications weighted by severity over time in a single formula. However, due to the large number of complications after cystectomy and UD, the CCI may exceed the upper limit.

METHODS

In an observational single-center cohort, 90-day postoperative complications in 1,313 consecutive patients undergoing cystectomy and UD from 2000 to 2017 were evaluated. Prospectively collected complications were graded according to the Clavien-Dindo classification (CDC). A modified Berne CCI was developed using an exponential function, which transforms the sum of the weights into a value between 0 and 100. The correlation between the Berne and original CCI values was depicted graphically. Finally, original CCI and Berne CCI values for each patient were extracted and compared. Predictive values of CCI scores for mortality or severe complications (CDC ≥IV) within 1 year postoperatively were investigated by use of multiple logistic regression analyses.

RESULTS

Overall complication rate was 82%, with CDC grade I to II in 56% and CDC grade IIIa to V in 27% respectively. Applying the original CCI, the upper limit was exceeded in 8 patients, with a maximal value of 119.1 (median 25.7 [interquartile range: 20.9-37.2]). The maximal value of the Berne CCI was 99.4 (21.2 [14.6-39.3]) for nondeath cases. The Berne CCI predicted the onset of death and severe complications between postoperative day 91 and 365 (both P <0.0001), whereas the original CCI was only predictive in interaction with other variables but not alone (P = 0.2772 and P = 0.0862, respectively).

CONCLUSION

The optimized Berne CCI depicts postoperative morbidity and burden within 90 days after cystectomy and UD without exceeding the upper index limit. It is specifically suited for longitudinal assessment of complications after cystectomy and UD taking into consideration every single complication and corresponding treatment. As the Berne CCI well predicted the onset of mortality and severe complications within 1 year postoperatively, this may allow a better preoperative patient counselling. It therefore warrants consideration for standardized reporting of complications after cystectomy and UD.

Comparison of the short-term clinical outcome between open and minimally invasive esophagectomy by comprehensive complication index

Objective

Esophagectomies are associated with high mortality and various complications. Previous studies reported on the short-term outcomes were heterogeneous and inconsistent in comparing minimally invasive esophagectomy (MIE) with traditional open esophagectomy (OE). The objective of this study is to compare the short-term outcomes between MIE and OE calculated using Comprehensive Complication Index (CCI) which incorporates all complication severities.

Materials and Methods

We did expertise-based randomized controlled trial from September 2014 to October 2015. A total of 144 patients with resectable cancer were randomly selected to be treated by OE or MIE. The CCI was calculated using the Clavien-Dindo classification grade of all postoperative complications collected. Demographic characteristics, preoperative clinical assessment, postoperative complications, and CCI of patients were compared between both groups.

Results

Among the 144 patients included in this study, 97 underwent OE and 47 underwent MIE. Demographics, preoperative clinical assessment, and inpatient mortality in both cohorts were almost identical. Eighty-four patients (86.6%) of OE group and 26 patients (55.3%) of MIE group suffered from complications. A significant difference was observed in blood transfusion (P = 0.04), moderate and severe pain (P < 0.01), and diarrhea (P = 0.03) between two groups. There was an obvious statistical significance of CCI between OE and MIE groups (P = 0.036).

Conclusions

The CCI is a promising scoring system that could be used to assess the severity of complications after esophagectomy. MIE could improve the short-term outcomes by reducing some mild and moderate complications.

Parenteral nutrition during neoadjuvant chemotherapy for patients with non-metastatic gastric or esophago-gastric cancer to reduce postoperative morbidity (PERCOG): study protocol for a randomized controlled trial

Background

The majority of patients with gastric or esophago-gastric cancer are at risk for malnutrition. Preoperative malnutrition was shown to increase the incidence of postoperative complications following abdominal surgery. However, it remains unclear if preoperative parenteral nutritional support during neoadjuvant chemotherapy (NACT) may be effective to reduce the rate of postoperative complications in these patients.

Methods/Design

The PERCOG trial is a randomized controlled multicenter observer-blinded trial, investigating if the improvement of the general condition of patients with non-metastasized gastric cancer or cancer of the esophago-gastric junction during NACT by supplemental parenteral nutrition can decrease the postoperative Comprehensive Complication Index (CCI). Statistical analysis of the primary endpoint measure (CCI on postoperative day 30) will be based on the intention-to-treat population. The global level of significance is set at 5% and the sample size (n = 150) is determined to assure a power of 80%.

Discussion

The results of the PERCOG trial will provide high-level evidence for clinical recommendations regarding the administration of preoperative supportive parenteral nutrition and provide all participating patients the opportunity of an improved treatment.

Trial registration

German Clinical Trials Register, DRKS00009451. Registered on 3 July 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2388-3) contains supplementary material, which is available to authorized users.