Robotic distal pancreatectomy, a novel standard of care? First benchmark values for surgical outcomes from 14 international expert centers

Objective

Robotic distal pancreatectomy (DP) is emerging as the preferred treatment for body and tail tumors of the pancreas. To enable conclusive comparisons with the standard open or laparoscopic approaches and robotic surgery among centers, novel benchmark outcome values are urgently needed. Therefore, the aim of this study was to identify benchmark values from expert centers beyond the learning curve.

Methods

This multicenter study analyzed outcomes from consecutive patients undergoing robotic DP for resectable malignant or benign lesions from 14 international expert centers. After the learning curve, defined as the first 10 cases of robotic DP, all consecutive patients were included from the start of the program up to June 2020 with a minimum follow-up of 1 year. Benchmark patients were those without significant comorbidities including obesity (BMI >35 kg/m2) cardiac disease, chronic pulmonary disease.

Benchmark cutoff values were derived from the 75th or the 25th percentile of the median values of all benchmark centers.

Results

After reaching the learning curve, 289 (47%) of a total of 614 consecutive patients qualified as benchmark cases. The proportion of benchmark patients varied between 24%-64% per center. Benchmark cut-offs showed a low 6 month- postoperative mortality (<0.6%), but high overall morbidity (<58.3%). Benchmark cutoffs for operative time (<300 min), conversion rate (<3%), clinically relevant pancreatic fistulas (<26.9%), CCI at 90-days (<14.8), hospital stay (<7 days) and readmission rate (<22.9%). Benchmark cut-offs for complications remained unchanged after 3 months follow-up. For ductal adenocarcinoma benchmark cutoffs for number of lymph nodes were > 19 with an R0 resection rate of > 85%, and an overall survival of >86% and >52% after 1- and 5-years, respectively. Centers with a low cohort of benchmark patients (more difficult cases) had less clinically relevant pancreatic fistula (9% vs. 23%) and less overall complications (32% vs. 48%).

Conclusion

This benchmark analysis sets novel reference values for robotic DP, indicating favorable outcomes as compared to laparoscopic and open DP. These references values may serve for quality control of surgery in centers embarking in robotic DP, and include the procedure in the standard of care.

Punzi-loss:: a non-differentiable metric approximation for sensitivity optimisation in the search for new particles

We present the novel implementation of a non-differentiable metric approximation and a corresponding loss-scheduling aimed at the search for new particles of unknown mass in high energy physics experiments. We call the loss-scheduling, based on the minimisation of a figure-of-merit related function typical of particle physics, a Punzi-loss function, and the neural network that utilises this loss function a Punzi-net. We show that the Punzi-net outperforms standard multivariate analysis techniques and generalises well to mass hypotheses for which it was not trained. This is achieved by training a single classifier that provides a coherent and optimal classification of all signal hypotheses over the whole search space. Our result constitutes a complementary approach to fully differentiable analyses in particle physics. We implemented this work using PyTorch and provide users full access to a public repository containing all the codes and a training example.

A simple nomogram for early postoperative risk prediction of clinically relevant pancreatic fistula after pancreatoduodenectomy

PURPOSE

Postoperative pancreatic fistulae (POPF) present a serious and life-threatening complication after pancreatic head resections (PD). Therefore, reliable risk stratification to identify those at risk is urgently needed. The aim of this study was to identify postoperative laboratory parameters for the prediction of POPF in the early postoperative period.

METHODS

One hundred eighty-two patients who underwent PD from 2012 until 2017 were retrospectively analyzed. Multivariate logistic regression was performed using the GLM (general linear model) method for model building. Two nomograms were created based on the GLM models of postoperative day one and postoperative day one to five. A cohort of 48 patients operated between 2018 and 2019 served as internal validation.

RESULTS

Clinically relevant pancreatic fistulae (CR-POPF) were present in 16% (n = 29) of patients. Patients with CR-POPF experienced significantly more insufficiencies of gastroenterostomies, delayed gastric emptying, and more extraluminal bleeding than patients without CR-POPF. Multivariate analysis revealed multiple postoperative predictive models, the best one including ASA, main pancreatic duct diameter, operation time, and serum lipase as well as leucocytes on day one. This model was able to predict CR-POPF with an accuracy of 90% and an AUC of 0.903. Two nomograms were created for easier use.

CONCLUSION

Clinically relevant fistula can be predicted using simple laboratory and clinical parameters. Not serum amylase, but serum lipase is an independent predictor of CR-POPF. Our simple nomograms may help in the identification of patients for early postoperative interventions.

Robotic versus laparoscopic distal pancreatectomy: multicentre analysis

BACKGROUND

The role of minimally invasive distal pancreatectomy is still unclear, and whether robotic distal pancreatectomy (RDP) offers benefits over laparoscopic distal pancreatectomy (LDP) is unknown because large multicentre studies are lacking. This study compared perioperative outcomes between RDP and LDP.

METHODS

A multicentre international propensity score-matched study included patients who underwent RDP or LDP for any indication in 21 European centres from six countries that performed at least 15 distal pancreatectomies annually (January 2011 to June 2019). Propensity score matching was based on preoperative characteristics in a 1 : 1 ratio. The primary outcome was the major morbidity rate (Clavien-Dindo grade IIIa or above).

RESULTS

A total of 1551 patients (407 RDP and 1144 LDP) were included in the study. Some 402 patients who had RDP were matched with 402 who underwent LDP. After matching, there was no difference between RDP and LDP groups in rates of major morbidity (14.2 versus 16.5 per cent respectively; P = 0.378), postoperative pancreatic fistula grade B/C (24.6 versus 26.5 per cent; P = 0.543) or 90-day mortality (0.5 versus 1.3 per cent; P = 0.268). RDP was associated with a longer duration of surgery than LDP (median 285 (i.q.r. 225-350) versus 240 (195-300) min respectively; P < 0.001), lower conversion rate (6.7 versus 15.2 per cent; P < 0.001), higher spleen preservation rate (81.4 versus 62.9 per cent; P = 0.001), longer hospital stay (median 8.5 (i.q.r. 7-12) versus 7 (6-10) days; P < 0.001) and lower readmission rate (11.0 versus 18.2 per cent; P = 0.004).

CONCLUSION

The major morbidity rate was comparable between RDP and LDP. RDP was associated with improved rates of conversion, spleen preservation and readmission, to the detriment of longer duration of surgery and hospital stay.

Laparoscopic versus open extended radical left pancreatectomy for pancreatic ductal adenocarcinoma: an international propensity-score matched study

BACKGROUND

A radical left pancreatectomy in patients with pancreatic ductal adenocarcinoma (PDAC) may require extended, multivisceral resections. The role of a laparoscopic approach in extended radical left pancreatectomy (ERLP) is unclear since comparative studies are lacking. The aim of this study was to compare outcomes after laparoscopic vs open ERLP in patients with PDAC.

METHODS

An international multicenter propensity-score matched study including patients who underwent either laparoscopic or open ERLP (L-ERLP; O-ERLP) for PDAC was performed (2007-2015). The ISGPS definition for extended resection was used. Primary outcomes were overall survival, margin negative rate (R0), and lymph node retrieval.

RESULTS

Between 2007 and 2015, 320 patients underwent ERLP in 34 centers from 12 countries (65 L-ERLP vs. 255 O-ERLP). After propensity-score matching, 44 L-ERLP could be matched to 44 O-ERLP. In the matched cohort, the conversion rate in L-ERLP group was 35%. The L-ERLP R0 resection rate (matched cohort) was comparable to O-ERLP (67% vs 48%; P = 0.063) but the lymph node yield was lower for L-ERLP than O-ERLP (median 11 vs 19, P = 0.023). L-ERLP was associated with less delayed gastric emptying (0% vs 16%, P = 0.006) and shorter hospital stay (median 9 vs 13 days, P = 0.005), as compared to O-ERLP. Outcomes were comparable for additional organ resections, vascular resections (besides splenic vessels), Clavien-Dindo grade ≥ III complications, or 90-day mortality (2% vs 2%, P = 0.973). The median overall survival was comparable between both groups (19 vs 20 months, P = 0.571). Conversion did not worsen outcomes in L-ERLP.

CONCLUSION

The laparoscopic approach may be used safely in selected patients requiring ERLP for PDAC, since morbidity, mortality, and overall survival seem comparable, as compared to O-ERLP. L-ERLP is associated with a high conversion rate and reduced lymph node yield but also with less delayed gastric emptying and a shorter hospital stay, as compared to O-ERLP.

Changes in attentional resources during the acquisition of laparoscopic surgical skills

Background

Increasing familiarity and practice might free up mental resources during laparoscopic surgical skills training. The aim of the study was to track changes in mental resource allocation during acquisition of laparoscopic surgical skills.

Methods

Medical students with no previous experience in laparoscopic surgery took part in a 5-week laparoscopic training curriculum. At the beginning and end of the training period, one of the training tasks was combined with a secondary auditory detection task that required pressing a foot switch for defined target tones, creating a dual-task situation. During execution of the two concurrent tasks, continuous electroencephalographic measurements were made, with special attention to the P300 component, an index of mental resources. Accuracy and reaction times of the secondary task were determined.

Results

All 14 participants successfully completed the training curriculum. Target times for successful completion of individual tasks decreased significantly during training sessions (P  <0.001 for all tasks). Comparing results before and after training showed a significant decrease in event-related brain potential amplitude at the parietal electrode cluster (P300 component, W = 67, P = 0.026), but there were no differences in accuracy (percentage correct responses: W = 48, P = 0.518) or reaction times (W = 42, P = 0.850) in the auditory detection task.

Conclusion

The P300 decrease in the secondary task over training demonstrated a shift of mental resources to the primary task: the surgical exercise. This indicates that, with more practice, mental resources are freed up for additional tasks.

Predictors for Survival in an International Cohort of Patients Undergoing Distal Pancreatectomy for Pancreatic Ductal Adenocarcinoma

Background

Surgical factors, including resection of Gerota’s fascia, R0-resection, and lymph node yield, may be associated with survival after distal pancreatectomy (DP) for pancreatic ductal adenocarcinoma (PDAC), but evidence from large multicenter studies is lacking. This study aimed to identify predictors for overall survival after DP for PDAC, especially those related to surgical technique.

Patients and Methods

Data from an international retrospective cohort including patients from 11 European countries and the USA who underwent DP for PDAC (2007–2015) were analyzed. Cox proportional hazard analyses were performed and included Gerota’s fascia resection, R0 resection, lymph node ratio, extended resection, and a minimally invasive approach.

Results

Overall, 1200 patients from 34 centers with median follow-up of 15 months [interquartile range (IQR) 5–31 months] and median survival period of 30 months [95% confidence interval (CI), 27–33 months] were included. Gerota’s fascia resection [hazard ratio (HR) 0.74; p = 0.019], R0 resection (HR 0.70; p = 0.006), and decreased lymph node ratio (HR 0.28; p < 0.001) were associated with improved overall survival, whereas extended resection (HR 1.75; p < 0.001) was associated with worse overall survival. A minimally invasive approach did not improve survival as compared with an open approach (HR 1.14; p = 0.350). Adjuvant chemotherapy (HR 0.67; p = 0.003) was also associated with improved overall survival.

Conclusions

This international cohort identified Gerota’s fascia resection, R0 resection, and decreased lymph node ratio as factors associated with improved overall survival during DP for PDAC. Surgeons should strive for R0 resection and adequate lymphadenectomy and could also consider Gerota’s fascia resection in their routine surgical approach.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08658-5) contains supplementary material, which is available to authorized users.

Computerized Medical Evidence-Based Decision Assistance System "MEBDAS®" improves in-hospital outcome after pancreatoduodenectomy for pancreatic cancer

BACKGROUND

Indication for pancreatoduodenectomy for pancreatic cancer can be challenging. Wrong decisions in indication processes lead to significant health impairments. Computerized decision support systems can take over parts of decision-making processes, making them more accurate. MEBDAS® is a decision-supporting software that predicts outcomes of proposed treatments.

AIM

to determine the decision concordance between MEBDAS® and multidisciplinary tumour board (MTB) and the impact of MEBDAS® on in-hospital outcome at different indication thresholds.

METHODS

126 patients with pancreatoduodenectomy from a high-volume university hospital were included. Outcome indicators were in-hospital mortality, Comprehensive Complication Index (CCI®), therapy-related loss of "Quality-Adjusted-Life-Day" (QALD-loss) and prognostic gain of treatment-related "Quality-Adjusted-Life-Year" (QALY-gain).

RESULTS

The concordance of decisions was 94.4% at the indication threshold of 0. By raising the indication threshold to 1 year, the concordance decreased to 0%, the in-hospital-mortality dropped from 2.52% to 0%, the CCI® decreased from 26.47 to 13.90, the therapy-related QALD-loss declined from 21.53 to 16.22 days and the prognostic QALY-gain increased from 0.374 to 0.906 years. At IT = 0.250 years, the concordance was 61.11% and differences between MTB and MEBDAS®-group were highly significant (p < 0.001) for all outcome parameters: mortality (3.97% vs. 1.30%), CCI® (28.96 vs. 18.29), therapy-related QALD-loss (24.41 vs. 15.19 days) and QALY-gain (0.351 vs. 0.501 years).

CONCLUSION

MEBDAS® decisions are superior to those of MTB in terms of in-hospital-outcome. The inclusion of MEBDAS® in decision procedure makes the indication more accurate and reduces morbidity and mortality. In addition, MEBDAS® can increase patients' competence by involving them in decision-making process.

Variation in pancreatoduodenectomy as delivered in two national audits

Background

Nationwide audits facilitate quality and outcome assessment of pancreatoduodenectomy. Differences may exist between countries but studies comparing nationwide outcomes of pancreatoduodenectomy based on audits are lacking. This study aimed to compare the German and Dutch audits for external data validation.

Methods

Anonymized data from patients undergoing pancreatoduodenectomy between 2014 and 2016 were extracted from the German Society for General and Visceral Surgery StuDoQ|Pancreas and Dutch Pancreatic Cancer Audit, and compared using descriptive statistics. Univariable and multivariable risk analyses were undertaken.

Results

Overall, 4495 patients were included, 2489 in Germany and 2006 in the Netherlands. Adenocarcinoma was a more frequent indication for pancreatoduodenectomy in the Netherlands. German patients had worse ASA fitness grades, but Dutch patients had more pulmonary co-morbidity. Dutch patients underwent more minimally invasive surgery and venous resections, but fewer multivisceral resections. No difference was found in rates of grade B/C postoperative pancreatic fistula, grade C postpancreatectomy haemorrhage and in-hospital mortality. There was more centralization in the Netherlands (1·3 versus 13·3 per cent of pancreatoduodenectomies in very low-volume centres; P &lt; 0·001). In multivariable analysis, both hospital stay (difference 2·49 (95 per cent c.i. 1·18 to 3·80) days) and risk of reoperation (odds ratio (OR) 1·55, 95 per cent c.i. 1·22 to 1·97) were higher in the German audit, whereas risk of postoperative pneumonia (OR 0·57, 0·37 to 0·88) and readmission (OR 0·38, 0·30 to 0·49) were lower. Several baseline and surgical characteristics, including hospital volume, but not country, predicted mortality.

Conclusion

This comparison of the German and Dutch audits showed variation in case mix, surgical technique and centralization for pancreatoduodenectomy, but no difference in mortality and pancreas-specific complications.

Comparison of conservative versus surgical therapy for acute appendicitis with abscess in five German hospitals

INTRODUCTION

The aim of this study was to evaluate the effectiveness of initially conservative therapy compared to immediate appendectomy for acute appendicitis with abscess in terms of medical and economic outcomes.

METHODS

Of all the patients treated for appendicitis from January 2009 to December 2017 in five German hospitals, 240 were included in the study. Fifty-three patients received conservative (CON) and 195 patients received surgical (SUR) therapy as initial treatment.

RESULTS

Length of stay was similar (12.5 days in CON vs. 13.3 days in SUR, p = 0.530). Readmission rate was higher in the conservative group (54.7% vs. 6.2%, p < 0.001). The majority (53.7%) of the 41 operations in CON group were appendectomies (22 procedures), 1 (4.5%) of them was in the first hospital stay because of persisting symptoms, 21 (95.5%) after a recovery interval. Seven (33.3%) of the recovery appendectomies were performed due to persisting or recurrent symptoms and 14 (66.7%) due to the request of patient. Twenty-one patients (39.6%) in the CON group did not need surgery. The rates of complication-related operations per patient (0.04 versus 0.58, p < 0.001), conversions of surgical technique (1.9% vs. 34.9%, p = 0.0287), and extended resections (1.9% vs. 31.3%, p < 0.001) were higher in SUR group. Furthermore, morbidity, hospital costs, and loss in quality of life were significantly higher in the surgical group (17.0% vs. 66.2%, p < 0.001; € 5044 vs. € 8457, p < 0.001, and 4.3 days vs. 7.5 days, p < 0.001, CON vs. SUR).

CONCLUSION

Initially, conservative treatment for acute appendicitis with abscess is preferable to immediate surgical treatment in reduction of morbidity, hospital costs, and loss in quality of life.

Proteome Profiling of Primary Pancreatic Ductal Adenocarcinomas Undergoing Additive Chemoradiation Link ALDH1A1 to Early Local Recurrence and Chemoradiation Resistance

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis with frequent post-surgical local recurrence. The combination of adjuvant chemotherapy with radiotherapy is under consideration to achieve a prolonged progression-free survival (PFS). To date, few studies have determined the proteome profiles associated with response to adjuvant chemoradiation. We herein analyzed the proteomes of primary PDAC tumors subjected to additive chemoradiation after surgical resection and achieving short PFS (median 6 months) versus prolonged PFS (median 28 months). Proteomic analysis revealed the overexpression of Aldehyde Dehydrogenase 1 Family Member A1 (ALDH1A1) and Monoamine Oxidase A (MAOA) in the short PFS cohort, which were corroborated by immunohistochemistry. In vitro, specific inhibition of ALDH1A1 by A37 in combination with gemcitabine, radiation, and chemoradiation lowered cell viability and augmented cell death in MiaPaCa-2 and Panc 05.04 cells. ALDH1A1 silencing in both cell lines dampened cell proliferation, cell metabolism, and colony formation. In MiaPaCa-2 cells, ALDH1A1 silencing sensitized cells towards treatment with gemcitabine, radiation or chemoradiation. In Panc 05.04, increased cell death was observed upon gemcitabine treatment only. These findings are in line with previous studies that have suggested a role of ALDH1A1 chemoradiation resistance, e.g., in esophageal cancer. In summary, we present one of the first proteome studies to investigate the responsiveness of PDAC to chemoradiation and provide further evidence for a role of ALDH1A1 in therapy resistance.

Is there any role for minimally invasive surgery in NET?

Neuroendocrine tumors (NET) represent the variability of almost benign lesions either secreting hormones occurring as a single lesion up to malignant lesions with metastatic potential. Treatment of NET is usually performed by surgical resection. Due to the rarity of NET, surgical treatment is mainly based on the experience and recommendations of experts and less on the basis of prospective randomized studies. In addition, the development and establishment of new surgical procedures is made more difficult by their rarity. The development of laparoscopic-assisted surgery has significantly improved the treatment of many diseases. Due to the well-known advantages of laparoscopic surgery, this method has also been increasingly used to treat NET. However, due to limited comparative data, the assumed superiority of laparoscopic surgery in the area NET remains often unclear or not yet proven. This review focuses on the present usage of laparoscopic techniques in the area of NET. Relating to the current literature, this review presents the evidence of various laparoscopic procedures for treatment of adrenal, pancreatic and intestine NET as well as extraadrenal pheochromocytoma and neuroendocrine liver metastases. Further, this review focuses on recent new developments of minimally invasive surgery in the area of NET. Here, robotic-assisted surgery and single-port surgery are promising approaches.

[Laparoscopic pancreatic resection]

INTRODUCTION AND PURPOSE

Despite being technically challenging, laparoscopic surgical procedures are increasingly being used also in pancreatic surgery. This review attempts to evaluate these procedures based on the currently available literature against the background of the high mortality of pancreatic surgery observed nationwide and the as yet unclear oncological validation of these procedures.

MATERIAL AND METHODS

Recently published retrospective cohort and register trials have evaluated not only perioperative outcome but also long-term survival after laparoscopic pancreatic resection.

RESULTS AND CONCLUSION

Laparoscopic interventions are increasingly being used for treatment of malignant tumors of the pancreas. The advantages of laparoscopy, such as less intraoperative blood loss, reduced postoperative pain and a shorter duration of hospital stay, have all been demonstrated in retrospective trials. Equivalent long-term survival after oncological laparoscopic pancreatic surgery compared to open procedures was also observed in these trials; however, mortality even after laparoscopic pancreatic surgery was found to be significantly increased in low-volume centers. Prospective trials are still needed to prove adequate oncological treatment. Laparoskopische Verfahren haben sich in den letzten Jahren in fast allen Bereichen der Chirurgie quasi zum Standard entwickelt und werden von Patienten zunehmend nachgefragt. Die kosmetischen Ergebnisse sind deutlich besser als bei konventionellem Vorgehen und sie reduzieren unter anderem den postoperativen Schmerz, Schmerzmittelbedarf sowie den Krankenhausaufenthalt [29]. Daher ist es wenig überraschend, dass minimal-invasive Verfahren auch bei technisch hochkomplexen Eingriffen, wie z. B. am Pankreas, zunehmend eingesetzt werden. Allerdings wird ihr Einsatz hier noch immer kontrovers diskutiert.

[Pancreaticogastrostomy: when and how?]

BACKGROUND

Pancreaticojejunostomy and pancreaticogastrostomy are the two techniques for pancreatic anastomosis that are widely established for the reconstruction after pancreaticoduodenectomy. Pancreaticogastrostomy is the most recent and to date less frequently performed method, the history, techniques and indications of which are presented.

METHOD

Review of the literature and current evidence.

RESULTS

Current evidence from randomized controlled trials and meta-analyses does not demonstrate significant differences in complication rates or pancreatic function after pancreaticogastrostomy versus pancreaticojejunostomy.

CONCLUSION

Pancreaticogastrostomy is the technically less demanding procedure, offering at least the same level of safety as pancreaticojejunostomy. Minimally invasive and parenchyma-sparing procedures provide new areas of application for this anastomotic technique.

[Laparoscopic Division of the Arcuate Ligament: Treatment of the Coeliac Artery Compression Syndrome]

Objective: The coeliac artery compression syndrome, first described by Harjola und Dunbar, results from the coeliac artery and plexus being compressed by the arcuate ligament at their origin. The clinical symptoms are postprandial pain and weight loss and the syndrome significantly restricts patients' quality of life. In rare cases, an epigastric bruit is detected on clinical examination. Laparoscopic division of the arcuate ligament is a successful option for the treatment of the coeliac artery compression syndrome. Indications: Laparoscopic decompression is indicated for patients with a symptom triad of postprandial pain, weight loss and epigastric bruit and radiologic confirmation of coeliac artery compression by duplex sonography, computed tomography angiography or magnetic resonance angiography. Procedure: The operative strategy is based on the division of the arcuate ligament following its visualisation above the origin of the coeliac artery from the abdominal aorta. Conclusion: The laparoscopic division of the arcuate ligament and the resection of the coeliac plexus are a largely uneventful, minimally-invasive option to treat the coeliac artery compression syndrome and restore patients' quality of life.

Predictors of Morbidity and Mortality in Esophageal Perforation: Retrospective Study of 80 Patients

Background and Aims:

Esophageal perforation is a life-threatening disease. Factors impacting morbidity and mortality include the cause and site of the perforation, the time to diagnosis, and the therapeutic procedure. This study aimed to identify risk factors for morbidity and mortality after esophageal perforation.

Patients and Methods:

This retrospective study analyzed data collected from all patients treated for esophageal perforation at the Department of Surgery, University of Schleswig–Holstein, Luebeck Campus, from January 1986 through December 2011.

Results:

Altogether, 80 patients (52 men, 28 women; mean age 65 years) were treated. The cause of perforation was intraluminal in 44 (55%) (group A) and extraluminal in 2 (3%) (group B). Spontaneous perforations were observed in 12 (15%) (group C). Perforations were due to a preexisting esophageal disease in 22 (28%) (group D). The survival rate was higher for group A (82%) than for groups B (50%), C (57%), and D (59%). The distal third of the esophagus had the highest prevalence of perforations (49, 61%) independent of the cause. Mortality, however, was independent of the perforation site. Perforations were diagnosed within 24 h in 57% (n = 46) of patients, associated with a statistically significant lower mortality rate (p = 0.035). Altogether, 40 patients underwent non-operative treatment, and among those 27 had endoscopic treatment. Emergency thoracic surgery was performed in 40 patients: direct suture of the defect (n = 26), partial esophageal resection (n = 11), other (n = 3). Significantly higher morbidity (p = 0.007) and prolonged hospitalization (p < 0.0001) was observed among patients who underwent emergency surgery. Mortality was higher in the surgical group (14/40) than in the non-operative treatment group (9/40) but without statistical significance.

Conclusion:

Intraluminal perforations, rapid initiation of therapy, and non-operative treatment were associated with favorable outcomes. The perforation site did not have an impact on outcomes. Esophageal resection was associated with high mortality.

[Adequate fluid resuscitation in septic shock with high catecholamine doses]

BACKGROUND

Appropriate fluid resuscitation is a fundamental aspect for the hemodynamic management of septic shock patients and should ideally be achieved before vasopressors and positive inotropic substances are administered. The development of hemodynamic monitoring has revealed that in some cases patients had been improperly treated with high-dose catecholamines for initially insufficient fluid resuscitation. The aim of this study was to show that in some cases it is possible to actively reduce catecholamines by a volume challenge adapted according to the individual patient needs.

MATERIAL AND METHODS

In this retrospective observational study 29 patients with septic shock in a surgical intensive care unit (ICU) at a university hospital (17 male, 12 female, mean age 71 ± 10 years) on high-dose catecholamines (median values norepinephrine 0.204 µg/kg body weight/min, dobutamine 3.876 µg/kg/min and epinephrine 0.025 µg/kg/min, ranging up to 0.810 µg/kg/min, 22.222 µg/kg/min and 0.407 µg/kg/min in 28, 20 and 17 patients, respectively) were analyzed. The extremities of the patients were initially cold with a mottled marbled appearance whereas the mean arterial pressure (MAP) was ≥ 65 mmHg. The median central venous pressure (CVP) was 17 mmHg (range 55-34 mmHg) and the mean lactate concentration was 2.78 mmol/l (range 0.93-10.67 mmol/l). The standard therapy concept consisted of a forced volume challenge combined with active reduction of catecholamines to achieve an adequate fluid loading status, guided by the passive leg raising test (PLR), clinical signs and in 19 cases by hemodynamic monitoring (pulmonary artery catheter Vigilance II(™) n = 10, FloTrac(™), Vigileo(™) n = 9 and PreSep(™) n = 5; Edwards Life Sciences). The forced volume challenge was stopped after clinical improvement with rewarmed extremities, increasing diuresis volumes and lack of improvement by PLR.

RESULTS

Catecholamine doses could be significantly reduced in all patients: norepinephrine to 0 µg/kg/min, dobutamine to 1.852 µg/kg/min and epinephrine to 0 µg/kg/min (up to 0.133 µg/kg/min, 6.289 µg/kg/min and 0.091 µg/kg/min, respectively, p < 0.05 Wilcoxon signed rank test). Volume challenge test: + 4,500 ml Ringer solution (range 0-24,000 ml) and 1,000 ml hydroxyethyl starch (range 0-2,500 ml) and mean fluid balance + 6,465 ml (range + 2,040 ml to + 27,255 ml). The median weaning time from catecholamines was 12 h (range 4-43 h). After treatment all patients showed rewarmed extremities and a decrease in mean lactate levels from 2.78 mmol/l (range 0.93-10.67 mmol/l) to 2.05 mmol/l (range 0.7-5.4 mmol/l). The measured hemodynamic constellations showed clear interindividual differences but no cardiac deterioration occurred. The median oxygenation index (paO2/FiO2) showed a statistically insignificant change from 264 mmHg (range 75-418 mmHg) to 250 mmHg (range 120-467 mmHg). Of the patients 20 survived and 9 died.

CONCLUSION

It is possible to wean a substantial proportion of septic shock patients from high-dose catecholamines in combination with a needs-adapted forced volume challenge test. The importance of appropriate fluid loading prior to the use of high catecholamine doses should be a main subject of discussion in patients with severe septic shock and was confirmed in this study. This should be oriented to clinical and if possible, hemodynamic parameters and should not be underestimated.

[An Experimental Set-Up for Navigated-Contrast-Agent and Radiation Sparing Endovascular Aortic Repair (Nav-CARS EVAR)]

INTRODUCTION

Over the last decade endovascular stenting of aortic aneurysm (EVAR) has been developed from single centre experiences to a standard procedure. With increasing clinical expertise and medical technology advances treatment of even complex aneurysms are feasible by endovascular methods. One integral part for the success of this minimally invasive procedure is innovative and improved vascular imaging to generate exact measurements and correct placement of stent prosthesis. One of the greatest difficulty in learning and performing this endovascular therapy is the fact that the three-dimensional vascular tree has to be overlaid with the two-dimensional angiographic scene by the vascular surgeon.

MATERIAL AND METHODS

We report the development of real-time navigation software, which allows a three-dimensional endoluminal view of the vascular system during an EVAR procedure in patients with infrarenal aortic aneurysm. We used the preoperative planning CT angiography for three-dimensional reconstruction of aortic anatomy by volume-rendered segmentation. At the beginning of the intervention the relevant landmarks are matched in real-time with the two-dimensional angiographic scene. During the intervention the software continously registers the position of the guide-wire or the stent. An additional 3D-screen shows the generated endoluminal view during the whole intervention in real-time.

RESULTS

We examined the combination of hardware and software components including complex image registration and fibre optic sensor technology (fibre-bragg navigation) with integration in stent graft introducer sheaths using patient-specific vascular phantoms in an experimental setting. From a technical point of view the feasibility of fibre-Bragg navigation has been proven in our experimental setting with patient-based vascular models. Three-dimensional preoperative planning including registration and simulation of virtual angioscopy in real time are realised.

CONCLUSION

The aim of the Nav-CARS-EVAR concept is reduction of contrast medium and radiation dose by a three-dimensional navigation during the EVAR procedure. To implement fibre-Bragg navigation further experimental studies are necessary to verify accuracy before clinical application.

[Internal hernias after bariatric surgery]

Hernias are among the most common long-term complications after bariatric surgery. Besides incisional hernias, which occur very often after conventional open bariatric surgery, internal hernias after bariatric surgery constitute a special challenge. The incidence of internal hernias after bariatric surgery is more common than for other upper gastrointestinal tract operations. Internal hernias are not limited to laparoscopic procedures but are also observed after conventional open gastric bypass surgery. As the incidence is significantly increased after laparoscopic interventions, there seems to be a close association with minimally invasive procedures. The clinical symptoms of internal hernias without complete obstruction are non-specific and the correct diagnosis is often not straightforward. In addition to the aspects of prevention of internal hernias in laparoscopic surgery, this article discusses the diagnosis and treatment, taking into account the various forms of internal hernia after bariatric operations.

Lung Sealing with the Sandwich-Technique: A New Surgical Method to Deal with the Emphysematous Lung

The persistent air leak is a common and sometimes difficult to manage complication after major pulmonary resections. Especially in cases with lung emphysema spontaneous sealing of the lung surface under conservative therapy can be prolonged or even fail and a reoperation to close the damaged visceral pleura might be necessary. An ideal surgical solution to deal with this problem is not known, all of the techniques have advantages but also limitations and additional operations should be avoided in this group of frail patients. In this paper a new surgical method to seal the lung surface is presented based on two exemplary cases and our clinical experience. Basically, two stripes of fleece bounded fibrin based sealant are put on the visceral pleura parallel to the wound, which will be then closed by multiple stitches of absorbable suture line inserted through the stripes. Afterwards, a second layer of the same sealant will be placed over it to cover the suture with a narrow overlapping in all directions to the adjacent visceral pleura (Sandwich-Technique). In our experience, this technique can be used to successfully prevent or treat persistent air leaks especially in patients with lung emphysema in whom otherwise treatment options are limited.

ABBREVIATIONS

VATS = video-assisted thoracoscopic surgery POD = postoperative day LVRS = lung volume reduction surgery FEV1 = forced expiratory volume in the first second DLCO = diffusing capacity of the lung for carbon monoxide.

Cancer cell invasion and EMT marker expression: a three-dimensional study of the human cancer-host interface

Cancer cell invasion takes place at the cancer-host interface and is a prerequisite for distant metastasis. The relationships between current biological and clinical concepts such as cell migration modes, tumour budding and epithelial-mesenchymal transition (EMT) remains unclear in several aspects, especially for the 'real' situation in human cancer. We developed a novel method that provides exact three-dimensional (3D) information on both microscopic morphology and gene expression, over a virtually unlimited spatial range, by reconstruction from serial immunostained tissue slices. Quantitative 3D assessment of tumour budding at the cancer-host interface in human pancreatic, colorectal, lung and breast adenocarcinoma suggests collective cell migration as the mechanism of cancer cell invasion, while single cancer cell migration seems to be virtually absent. Budding tumour cells display a shift towards spindle-like as well as a rounded morphology. This is associated with decreased E-cadherin staining intensity and a shift from membranous to cytoplasmic staining, as well as increased nuclear ZEB1 expression.

[Management of mesenteric ischemia and mesenteric vein thrombosis]

Acute mesenteric ischemia is secondary to acute embolic disease or thrombosis of the superior mesenteric artery. Further pathologies that manifest themselves with the same clinical presentation are thrombosis of the superior mesenteric vein and non-occlusive disease. The patients are admitted to the emergency room with an acute abdomen. Most patients are more than 70 years old. Known risk factors for mesenteric ischemia are cardiac diseases as atrial fibrillation, aneurysms of the aorta and the visceral arteries, occlusive arterial diseases, tumorigenic compression of the vessel and several diseases that result in a reduction of the flow and intravascular volume in the superior mesenteric artery. The golden standard in the diagnosis of acute mesenteric ischemia is CT-angiography of the abdominal vessels with 3 D reconstruction. The therapy is different and dependent from the underlying pathology. A statistically significantly elevated mortality of more than 95% is associated with a delay of surgical or interventional therapy of more than 12 hours after the initial symptoms and non-occlusive mesenteric ischemia. Because of the advanced age of the patients and the co-morbidities a non-surgical interventional re-canalisation of the superior mesenteric vessels is recommended. A laparotomy is necessary in all patients with peritonitis and/or bowel necrosis or perforation.

[Freiburg index of patient satisfaction: interdisciplinary validation of a new psychometric questionnaire to describe treatment-related patient satisfaction]

BACKGROUND

The recently introduced Freiburg index of patient satisfaction (FIPS) is a new questionnaire to assess treatment-related patient satisfaction after surgery and interventional procedures. The questionnaire had first been tested psychometrically in a mixed population of urology patients. The current study describes the results of an interdisciplinary validation. In addition, an English version is presented.

METHODS

The questionnaire was used in two cohorts of cardiology (n = 120) and surgical (n = 127) patients. The evaluation included a comprehensive methodological and statistical evaluation including validation in comparison to the ZUF-8 questionnaire.

RESULTS

The psychometric evaluation showed good results. The analyzed samples showed no missing values or ceiling effects. Furthermore, a high reliability (Cronbach's alpha 0.82), unidimensionality, sufficient distribution of values and validity (high correlation to the ZUF-8, r = 0.65, p < 0.001) of the questionnaire could be confirmed.

CONCLUSIONS

The FIPS constitutes an interdisciplinary validated questionnaire to evaluate treatment-related patient satisfaction which can be used to objectify and compare results from clinical studies and quality in patient care. Colleagues of English-speaking countries are invited to participate in the validation of the hereby presented English version.

Postpancreatectomy hemorrhage--incidence, treatment, and risk factors in over 1,000 pancreatic resections

BACKGROUND

Postpancreatectomy hemorrhage is a rare but often severe complication after pancreatic resection. The aim of this retrospective study was to define incidence and risk factors of postpancreatectomy hemorrhage and to evaluate treatment options and outcome.

PATIENTS AND METHODS

Clinical data was extracted from a prospectively maintained database. Descriptive statistics, univariate and multivariate risk factor analysis by binary logistic regression were performed with SPSS software at a significance level of p = 0.05.

RESULTS

N = 1,082 patients with pancreatic resections between 1994 and 2012 were included. Interventional angiography was successful in about half of extraluminal bleeding. A total of 78 patients (7.2 %) had postpancreatectomy hemorrhage (PPH), and 29 (2.7 %) were grade C PPH. Multivariate modeling disclosed a learning effect, age, BMI, male sex, intraoperative transfusion, portal venous and multivisceral resection, pancreatic fistula and preoperative biliary drainage as independent predictors of severe postpancreatectomy hemorrhage. High-risk histopathology, age, transfusion, pancreatic fistula, postpancreatectomy hemorrhage and pancreatojejunostomy in pancreatoduodenectomies were independent predictors of mortality.

CONCLUSIONS

Our study identifies clinically relevant risk factors for postpancreatectomy hemorrhage and mortality. Interventional treatment of extraluminal hemorrhage is successful in about half of the cases and if unsuccessful constitutes a valuable adjunct to operative hemostasis. Based on our observations, we propose a treatment scheme for PPH. Risk factor analysis suggests appropriate patient selection especially for extended resections and pancreatogastrostomy for reconstruction in pancreatoduodenectomy.

[Pancreatic anastomosis -- a video comparison of different techniques]

INTRODUCTION

The pancreatic anastomosis seems to be the most difficult and dangerous anastomosis in general surgery, especially in a soft pancreas. Many techniques have been described. The techniques most often used are: anastomosis of the pancreas to the jejunum as a pancreatico-jejunostomy (duct-to-mucosa anastomosis) or as a pancreato-jejunostomy (invaginating anastomosis). Another widely used anastomosis for reconstruction after pancreatic head resection is from the stomach to the pancreas, i.e., pancreato-gastrostomy. In literature the data concerning postoperative complications (pancreatic fistula, postoperative bleeding and others) are not consistent.

INDICATIONS

Reconstruction after pancreatic head resection.

PROCEDURE

Anastomosis between small intestine or stomach and the pancreas.

CONCLUSION

There is no gold standard for pancreatic anastomosis. Thus, of the different commonly used techniques, in our opinion, the best technique for each surgeon seems to be the one that he/she is most familiar with.

[Contribution of the Study Center of the German Surgical Society to evidence based surgery]

Since the Study Center of the German Surgical Society (SDGC) was established in 2003 it has been supporting surgeons to implement their ideas for multicenter randomized studies. Assistance is provided for development (sample size calculation, protocol, funding application) implementation (submission to ethics committee, data management, monitoring) and analysis (statistical analysis, publication) in close collaboration with biometricians and data managers. Currently more than 2,500 patients have been included in 11 trials. The most complex SDGC study (SYNCHRONOUS) so far with up to 80 participating centers has been activated in September 2011. Furthermore, there is an increasing relevance for systematic reviews and meta analyses with regard to the development of studies and aggregation of results. For this reason a systematic review working group was established within the SDGC. To date 13 publications have been completed and 8 more are underway.

[Functional-aesthetic rhinosurgery patients: psychometric parameters]

BACKGROUND

The aim of this study was to acquire psychometric parameters in patients desiring functional-aesthetic nasal surgery.

MATERIAL AND METHODS

Over a 1-year period, 101 patients were consecutively examined at the ENT department of the University of Ulm. Septoplasty or septorhinoplasty was indicated in all cases. The acquisition of psychometric data was performed by means of standardised and validated questionnaires. Data relating to anxiety, depression, private and public self-awareness as well as general satisfaction with oneself and in particular with one's nose was collected.

RESULTS

Patients demonstrated greater levels of fear, self-awareness in public and dissatisfaction with their nose. The greatest expectation concerning the outcome of the operation was the improvement of nasal obstruction. Altering the outward appearance of the nose was a secondary consideration.

CONCLUSION

The screening presented here enables ENT surgeons to identify possible "problem" patients before functional-aesthetic nasal surgery.

[Laparoscopic resection of the pancreatic head. Feasibility and perioperative results]

BACKGROUND

Whereas pancreatic tail resection is routinely and safely performed in several institutions, laparoscopic resection of the pancreatic head is only performed by a handful of surgeons worldwide, none of them in Germany.

PATIENTS AND METHODS

We review our experience with 9 laparoscopic pancreatic head resections (lap-PPPD) performed between March and September 2010. The operations were performed using a hybrid approach with complete laparoscopic pylorus-preserving pancreatic head resection and successive reconstruction via a small retrieval incision. Perioperative outcome was compared to 605 open pancreatic head resections (1997-2010).

RESULTS

In the group lap-PPPD 3 out of 9 conversions had to be performed due to oncologic reasons. There were no significant differences in perioperative outcome when comparing open-PPPD to lap-PPPD.

CONCLUSION

Laparoscopic pancreatic head resection with hybrid open reconstruction combines the potential advantages of laparoscopic resection with the safety of an open pancreatic anastomosis. Even at the beginning of the learning curve the procedure can be performed with no concessions to safety or duration of the operation.

Ectopic ACTH-syndrome due to a neuroendocrine tumour of the appendix

Ectopic ACTH production causes 10% of Cushing's syndromes. The diagnostic workup is difficult, can last more than 6 months (> 50% of cases), and the underlying tumour is still frequently not located (12%). Carcinoid tumours of the appendix are frequent and are revealed in 0.3% of patients undergoing routine appendectomy. However, neuroendocrine tumours of the appendix with ACTH production are an extremely rare entity. Here we report the case of a female patient with clinically overt Cushing's syndrome due to ectopic ACTH-production from a carcinoid tumour of the appendix. During the diagnostic workup, repeated endocrine tests, multiple different imaging modalities and frequent and lengthy hospitalisations were necessary. Wrongly, even a neurosurgical pituitary exploration was performed. After 12 months from the initial admission, the tumour was finally detected by an ¹⁸F-fluoro-L-dihydroxyphenylalanine (¹⁸FDOPA PET) and an appendectomy followed by right hemicolectomy were performed. The patient recovered rapidly and the symptoms from the hypercortisolism were no more present.In this case, we discuss the multitude of problems, which may delay the diagnosis and the pitfalls, that should be avoided in order to locate the tumour and to initiate adequate therapy as early as possible. Furthermore, our case demonstrates the complexity of diagnostic procedures, which demand most of the times a multidisciplinary approach. In this setting, regular follow-ups in short time intervals and the use of novel imaging techniques can finally cut the diagnostic "Gordian knot".

[Carcinoma of the pancreas: current status of multimodal therapy]

Only multimodal treatment concepts may potentially improve the persisting poor prognosis of the carcinoma of the pancreas. In specialized centres surgery has reached a high level of security with a very low level of mortality. Infiltrations of the mesenterico-portal axis are not a contraindication to a curative oncological surgery. R0 and R1 resections should be followed by adjuvant chemotherapy with gemcitabine. Currently there is no evidence of benefit for a neoadjuvant radiochemotherapy in primary resectable carcinomas of the pancreas. The survival rates of primary resectable carcinoma patients with neoadjuvant pre-treatment correspond to those of primary resectable carcinoma patients with adjuvant therapy. Due to the high perioperative morbidity, some patients do not gain access to the adjuvant therapy within a reasonable time frame. Therefore, the significance of neoadjuvant therapy for resectable tumours should be re-evaluated in prospective randomised trials. In about one third of the patients with primary irresectable carcinomas of the pancreas, a radical resection can be performed after neoadjuvant radiochemotherapy. For this patient group randomised prospective trials are urgently needed. In this context, however, only an experienced pancreatic surgeon can decide about the resectability or irresectability of a pancreatic tumour.

[Insurance costs in pancreatic surgery : does the pecuniary aspect indicate formation of centers?]

BACKGROUND

Pancreatic resections in specialized centers are associated with low mortality, however, still with high morbidity. The complication rate can be reduced by long-term experience in high volume centers. In this study the influence of complications on costs in the German DRG system were analyzed.

PATIENTS AND METHODS

Data regarding operation time, hospital stay, complications and costs of 36 patients undergoing pancreatic head resection in the years 2005 and 2006 were collected and analyzed retrospectively. Statistical analysis was performed using the Mann-Whitney U-test. A p-value of p<0.05 was considered statistically significant.

RESULTS

Postoperative complications caused an increase in the duration of hospital stay from a median of 16 (range 11-38) to 33 (10-69) days. Costs, especially for ICU treatment and radiographic diagnostics, rose significantly. The average overall costs were 10,015 EUR (range 8,099-14,785 EUR) in patients without complications (n = 21) and 15,340 EUR (9,368-31,418 EUR) in patients with complications (n = 15). In contrast, according to the German DRG system 13,835 EUR (10,441-15,062 EUR) and 15,062 EUR (10,441-33,217 EUR) were refunded on average, respectively.

CONCLUSIONS

This case-cost calculation proves that pancreatic surgery in the context of the German DRG system can only be performed economically neutral in centers with low complications rates. The concentration of pancreatic surgery to centers with low complications rates, namely high volume centers, must be recommended from an economic point of view.

[Liver metastases: pathogenesis and oncogenesis]

Liver metastases are most often caused by colorectal cancer, followed by pancreatic and breast cancer. Metastasis constitutes the last step of malignant tumor progression. Molecular investigations point towards an important role of the epithelial-mesenchymal transition (EMT) as a mechanism of local invasion and distant metastasis formation. Furthermore, the existence of a subpopulation of cancer stem cells (CSC) could be demonstrated in solid tumors. Recent observations show a dynamic induction of CSC properties by EMT. Therefore, theoretically migrating cancer stem cells (MCSC) can be induced which form the basis for the development of distant metastases.

Reinforcement of colonic anastomoses with a collagenous double-layer matrix extracted from porcine dermis

BACKGROUND

Anastomotic leakage is a major factor for morbidity in colorectal surgery. Anastomotic reinforcement with biological or synthetic materials has been claimed to be useful in preventing anastomotic leakage.

METHODS

We evaluated a non-cross-linked collagenous matrix Bio-Gide (BG) for sealing colonic anastomoses in a rodent model. The animals were investigated for 4, 30 and 90 days. Macroscopic examination, histological examination and measurement of bursting pressure were performed. The anastomotic stricture rate was evaluated by radiographic contrast enema.

RESULTS

Microscopically anastomoses sealed by BG showed impaired anastomotic healing. Blood vessel ingrowth and collagen deposition were decreased without reaching significance after 4 days. The anastomotic bursting pressure was significantly decreased (p = 0.0454) in the early phase of healing. Anastomotic neovascularization was significantly decreased compared to the control group after 30 (p = 0.0058) and 90 days (p = 0.0275). Although no difference in anastomotic stricture rate was evident, the rate of intra-abdominal adhesions was significantly increased after 30 (p = 0.0124) and 90 days (p = 0.0281).

CONCLUSION

BG failed to improve colonic anastomotic healing. Early anastomotic healing was impaired if anastomoses were reinforced with BG. BG did not affect the anastomotic stricture rate for up to 3 months; nevertheless, intra-abdominal adhesions were increased.