A pleiotropy scan to discover new susceptibility loci for pancreatic ductal adenocarcinoma.

Pleiotropic variants (i.e., genetic polymorphisms influencing more than one phenotype) are often associated with cancer risk. A scan of pleiotropic variants was successfully conducted ten years ago in relation to pancreatic ductal adenocarcinoma susceptibility. However, in the last decade, genetic association studies performed on several human traits have greatly increased the number of known pleiotropic variants. Based on the hypothesis that variants already associated with a least one trait have a higher probability of association with other traits, 61,052 variants reported to be associated by at least one genome wide association study (GWAS) with at least one human trait were tested in the present study consisting of two phases (discovery and validation), comprising a total of 16,055 pancreatic ductal adenocarcinoma (PDAC) cases and 212,149 controls. The meta-analysis of the two phases showed two loci (10q21.1-rs4948550 (P=6.52×10-5) and 7q36.3-rs288762 (P=3.03×10-5) potentially associated with PDAC risk. 10q21.1-rs4948550 shows a high degree of pleiotropy and it is also associated with colorectal cancer risk while 7q36.3-rs288762 is situated 28,558 base pairs upstream of the Sonic Hedgehog (SHH) gene, which is involved in the cell differentiation process and PDAC etiopathogenesis. In conclusion, none of the single nucleotide polymorphisms (SNPs) showed a formally statistically significant association after correction for multiple testing. However, given their pleiotropic nature and association with various human traits including colorectal cancer, the two SNPs showing the best associations with PDAC risk merit further investigation through fine mapping and ad hoc functional studies.

Decreased mebrofenin uptake in patients with non-colorectal liver tumors requiring liver volume augmentation-a single-center analysis.

BACKGROUND: Posthepatectomy liver failure (PHLF) remains a life-threatening complication after hepatectomy. To reduce PHLF, a preoperative assessment of liver function is indispensable. For this purpose, 99mTc-mebrofenin hepatobiliary scintigraphy with SPECT (MSPECT) can be used. The aim of the current study was to evaluate the predictive value of MSPECT for PHLF in patients with non-colorectal liver tumors (NCRLT) compared to patients with colorectal liver metastasis (CRLM) undergoing extended liver resection. METHODS: We included all patients undergoing extended liver resections via two-stage procedures between January 2019 and December 2021 at the University Medical Center Hamburg-Eppendorf, Germany. All patients received a preoperative MSPECT. RESULTS: Twenty patients were included. In every fourth patient, PHLF was observed. Four patients had PHLF grade C. There were no differences between patients with CRLM and NCRLT regarding PHLF rate and future liver remnant (FLR) volume. Patients with CRLM had higher mebrofenin uptake in the FLR compared to those with NCRLT (2.49%/min/m2 vs. 1.51%/min/m2; p = 0.004). CONCLUSION: Mebrofenin uptake in patients with NCRLT was lower compared to those patients with CRLM. However, there was no difference in the PHLF rate and FLR volume. Cut-off values for the mebrofenin uptake might need adjustments for different surgical indications, surgical procedures, and underlying diseases.

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.

Technical advances in surgery for pancreatic cancer.

BACKGROUND: Multimodal treatment concepts enhance options for surgery in locally advanced pancreatic ductal adenocarcinoma (PDAC). This review provides an overview of technical advances to facilitate curative-intent resection in PDAC. METHODS: A review of the literature addressing current technical advances in surgery for PDAC was performed, and current state-of-the-art surgical techniques summarized. RESULTS: Artery-first and uncinate-first approaches, dissection of the anatomical triangle between the coeliac and superior mesenteric arteries and the portomesenteric vein, and radical antegrade modular pancreatosplenectomy were introduced to enhance the completeness of resection and reduce the risk of local recurrence. Elaborated techniques for resection and reconstruction of the mesenteric-portal vein axis and a venous bypass graft-first approach frequently allow resection of PDAC with venous involvement, even in patients with portal venous congestion and cavernous transformation. Arterial involvement does not preclude surgical resection per se, but may become surgically manageable with recent techniques of arterial divestment or arterial resection following neoadjuvant treatment. CONCLUSION: Advanced techniques of surgical resection and vessel reconstruction provide a toolkit for curative-intent surgery in borderline resectable and locally advanced PDAC. Effects of these surgical approaches on overall survival remain to be proven with high-level clinical evidence.

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.

Bedside hyperspectral imaging indicates a microcirculatory sepsis pattern - an observational study.

INTRODUCTION: Microcirculatory alterations are key mechanisms in sepsis pathophysiology leading to tissue hypoxia, edema formation, and organ dysfunction. Hyperspectral imaging (HSI) is an emerging imaging technology that uses tissue-light interactions to evaluate biochemical tissue characteristics including tissue oxygenation, hemoglobin content and water content. Currently, clinical data for HSI technologies in critical ill patients are still limited. METHODS AND ANALYSIS: TIVITA® Tissue System was used to measure Tissue oxygenation (StO2), Tissue Hemoglobin Index (THI), Near Infrared Perfusion Index (NPI) and Tissue Water Index (TWI) in 25 healthy volunteers and 25 septic patients. HSI measurement sites were the palm, the fingertip, and a suprapatellar knee area. Septic patients were evaluated on admission to the ICU (E), 6 h afterwards (E+6) and three times a day (t3-t9) within a total observation period of 72 h. Primary outcome was the correlation of HSI results with daily SOFA-scores. RESULTS: Serial HSI at the three measurement sites in healthy volunteers showed a low mean variance expressing high retest reliability. HSI at E demonstrated significantly lower StO2 and NPI as well as higher TWI at the palm and fingertip in septic patients compared to healthy volunteers. StO2 and TWI showed corresponding results at the suprapatellar knee area. In septic patients, palm and fingertip THI identified survivors (E-t4) and revealed predictivity for 28-day mortality (E). Fingertip StO2 and THI correlated to SOFA-score on day 2. TWI was consistently increased in relation to the TWI range of healthy controls during the observation time. Palm TWI correlated positively with SOFA scores on day 3. DISCUSSION: HSI results in septic patients point to a distinctive microcirculatory pattern indicative of reduced skin oxygenation and perfusion quality combined with increased blood pooling and tissue water content. THI might possess risk-stratification properties and TWI could allow tissue edema evaluation in critically ill patients. CONCLUSION: HSI technologies could open new perspectives in microcirculatory monitoring by visualizing oxygenation and perfusion quality combined with tissue water content in critically ill patients - a prerequisite for future tissue perfusion guided therapy concepts in intensive care medicine.

Functional outcomes after laparoscopic versus robotic-assisted rectal resection: a systematic review and meta-analysis.

Surgical resection is crucial for curative treatment of rectal cancer. Through multidisciplinary treatment, including radiochemotherapy and total mesorectal excision, survival has improved substantially. Consequently, more patients have to deal with side effects of treatment. The most recently introduced surgical technique is robotic-assisted surgery (RAS) which seems equally effective in terms of oncological control compared to laparoscopy. However, RAS enables further advantages which maximize the precision of surgery, thus providing better functional outcomes such as sexual function or contience without compromising oncological results. This review was done according to the PRISMA and AMSTAR-II guidelines and registered with PROSPERO (CRD42018104519). The search was planned with PICO criteria and conducted on Medline, Web of Science and CENTRAL. All screening steps were performed by two independent reviewers. Inclusion criteria were original, comparative studies for laparoscopy vs. RAS for rectal cancer and reporting of functional outcomes. Quality was assessed with the Newcastle-Ottawa scale. The search retrieved 9703 hits, of which 51 studies with 24,319 patients were included. There was a lower rate of urinary retention (non-RCTs: Odds ratio (OR) [95% Confidence Interval (CI)] 0.65 [0.46, 0.92]; RCTs: OR[CI] 1.29[0.08, 21.47]), ileus (non-RCTs: OR[CI] 0.86[0.75, 0.98]; RCTs: OR[CI] 0.80[0.33, 1.93]), less urinary symptoms (non-RCTs mean difference (MD) [CI] - 0.60 [- 1.17, - 0.03]; RCTs: - 1.37 [- 4.18, 1.44]), and higher quality of life for RAS (only non-RCTs: MD[CI]: 2.99 [2.02, 3.95]). No significant differences were found for sexual function (non-RCTs: standardized MD[CI]: 0.46[- 0.13, 1.04]; RCTs: SMD[CI]: 0.09[- 0.14, 0.31]). The current meta-analysis suggests potential benefits for RAS over laparoscopy in terms of functional outcomes after rectal cancer resection. The current evidence is limited due to non-randomized controlled trials and reporting of functional outcomes as secondary endpoints.

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.

Radiological management of postoperative lymphorrhea.

PURPOSE: Postoperative lymphorrhea can occur after different surgical procedures and may prolong the hospital stay due to the need for specific treatment. In this work, the therapeutic significance of the radiological management of postoperative lymphorrhea was assessed and illustrated. METHOD: A standardized search of the literature was performed in PubMed applying the Medical Subject Headings (MeSH) term "lymphangiography." For the review, the inclusion criterion was "studies with original data on Lipiodol-based Conventional Lymphangiography (CL) with subsequent Percutaneous Lymphatic Intervention (PLI)." Different exclusion criteria were defined (e.g., studies with <15 patients). The collected data comprised of clinical background and indications, procedural aspects and types of PLI, and outcomes. In the form of a pictorial essay, each author illustrated a clinical case with CL and/or PLI. RESULTS: Seven studies (corresponding to evidence level 4 [Oxford Centre for Evidence-Based Medicine]) accounting for 196 patients were included in the synthesis and analysis of data. Preceding surgery resulting in postoperative lymphorrhea included different surgical procedures such as extended oncologic surgery or vascular surgery. Central (e.g., chylothorax) and peripheral (e.g., lymphocele) types of postoperative lymphorrhea with a drainage volume of 100-4000 ml/day underwent CL with subsequent PLI. The intervals between "preceding surgery and CL" and between "CL and PLI" were 2-330 days and 0-5 days, respectively. CL was performed before PLI to visualize the lymphatic pathology (e.g., leakage point or inflow lymph ducts), applying fluoroscopy, radiography, and/or computed tomography (CT). In total, seven different types of PLI were identified: (1) thoracic duct (or thoracic inflow lymph duct) embolization, (2) thoracic duct (or thoracic inflow lymph duct) maceration, (3) leakage point direct embolization, (4) inflow lymph node interstitial embolization, (5) inflow lymph duct (other than thoracic) embolization, (6) inflow lymph duct (other than thoracic) maceration, and (7) transvenous retrograde lymph duct embolization. CL-associated and PLI-associated technical success rates were 97-100% and 89-100%, respectively. The clinical success rate of CL and PLI was 73-95%. CL-associated and PLI-associated major complication rates were 0-3% and 0-5%, respectively. The combined CL- and PLI-associated 30-day mortality rate was 0%, and the overall mortality rate was 3% (corresponding to six patients). In the pictorial essay, the spectrum of CL and/or PLI was illustrated. CONCLUSION: The radiological management of postoperative lymphorrhea is feasible, safe, and effective. Standardized radiological treatments embedded in an interdisciplinary concept are a step towards improving outcomes.

Endoscopic versus surgical treatment for infected necrotizing pancreatitis: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To compare outcomes of endoscopic and surgical treatment for infected necrotizing pancreatitis (INP) based on results of randomized controlled trials (RCT). BACKGROUND: Treatment of INP has changed in the last two decades with adoption of interventional, endoscopic and minimally invasive surgical procedures for drainage and necrosectomy. However, this relies mostly on observational studies. METHODS: We performed a systematic review following Cochrane and PRISMA guidelines and AMSTAR-2 criteria and searched CENTRAL, Medline and Web of Science. Randomized controlled trails that compared an endoscopic treatment to a surgical treatment for patients with infected walled-off necrosis and included one of the main outcomes were eligible for inclusion. The main outcomes were mortality and new onset multiple organ failure. Prospero registration ID: CRD42019126033 RESULTS: Three RCTs with 190 patients were included. Intention to treat analysis showed no difference in mortality. However, patients in the endoscopic group had statistically significant lower odds of experiencing new onset multiple organ failure (odds ratio (OR) confidence interval [CI] 0.31 [0.10, 0.98]) and were statistically less likely to suffer from perforations of visceral organs or enterocutaneous fistulae (OR [CI] 0.31 [0.10, 0.93]), and pancreatic fistulae (OR [CI] 0.09 [0.03, 0.28]). Patients with endoscopic treatment had a statistically significant lower mean hospital stay (Mean difference [CI] - 7.86 days [- 14.49, - 1.22]). No differences in bleeding requiring intervention, incisional hernia, exocrine or endocrine insufficiency or ICU stay were apparent. Overall certainty of evidence was moderate. CONCLUSION: There seem to be possible benefits of endoscopic treatment procedure. Given the heterogenous procedures in the surgical group as well as the low amount of randomized evidence, further studies are needed to evaluate the combination of different approaches and appropriate timepoints for interventions.

Germline BRCA2 K3326X and CHEK2 I157T mutations increase risk for sporadic pancreatic ductal adenocarcinoma.

Rare truncating BRCA2 K3326X (rs11571833) and pathogenic CHEK2 I157T (rs17879961) variants have previously been implicated in familial pancreatic ductal adenocarcinoma (PDAC), but not in sporadic cases. The effect of both mutations in important DNA repair genes on sporadic PDAC risk may shed light on the genetic architecture of this disease. Both mutations were genotyped in germline DNA from 2,935 sporadic PDAC cases and 5,626 control subjects within the PANcreatic Disease ReseArch (PANDoRA) consortium. Risk estimates were evaluated using multivariate unconditional logistic regression with adjustment for possible confounders such as sex, age and country of origin. Statistical analyses were two-sided with p values <0.05 considered significant. K3326X and I157T were associated with increased risk of developing sporadic PDAC (odds ratio (ORdom ) = 1.78, 95% confidence interval (CI) = 1.26-2.52, p = 1.19 × 10-3 and ORdom = 1.74, 95% CI = 1.15-2.63, p = 8.57 × 10-3 , respectively). Neither mutation was significantly associated with risk of developing early-onset PDAC. This retrospective study demonstrates novel risk estimates of K3326X and I157T in sporadic PDAC which suggest that upon validation and in combination with other established genetic and non-genetic risk factors, these mutations may be used to improve pancreatic cancer risk assessment in European populations. Identification of carriers of these risk alleles as high-risk groups may also facilitate screening or prevention strategies for such individuals, regardless of family history.

Meta-analysis of effect of routine enteral nutrition on postoperative outcomes after pancreatoduodenectomy.

BACKGROUND: The optimal nutritional treatment after pancreatoduodenectomy is still unclear. The aim of this meta-analysis was to investigate the impact of routine enteral nutrition following pancreatoduodenectomy on postoperative outcomes. METHODS: RCTs comparing enteral nutrition (regular oral intake with routine tube feeding) with non-enteral nutrition (regular oral intake with or without parenteral nutrition) after pancreatoduodenectomy were sought systematically in the MEDLINE, Cochrane Library and Web of Science databases. Postoperative data were extracted. Random-effects meta-analyses were performed to compare postoperative outcomes in the two arms, and pooled odds ratios (ORs) or mean differences (MDs) were calculated with 95 per cent confidence intervals. In subgroup analyses, the routes of nutrition were assessed. Percutaneous tube feeding and nasojejunal tube feeding were each compared with parenteral nutrition. RESULTS: Eight RCTs with a total of 955 patients were included. Enteral nutrition was associated with a lower incidence of infectious complications (OR 0·66, 95 per cent c.i. 0·43 to 0·99; P = 0·046) and a shorter length of hospital stay (MD -2·89 (95 per cent c.i. -4·99 to -0·80) days; P < 0·001) than non-enteral nutrition. Percutaneous tube feeding had a lower incidence of infectious complications (OR 0·47, 0·25 to 0·87; P = 0·017) and a shorter hospital stay (MD -1·56 (-2·13 to -0·98) days; P < 0·001) than parenteral nutrition (3 RCTs), whereas nasojejunal tube feeding was not associated with better postoperative outcomes (2 RCTs). CONCLUSION: As a supplement to regular oral diet, routine enteral nutrition, especially via a percutaneous enteral tube, may improve postoperative outcomes after pancreatoduodenectomy.

Meta-analysis of recurrence pattern after resection for pancreatic cancer.

BACKGROUND: Initial recurrence mapping of resected pancreatic ductal adenocarcinoma (PDAC) could help in stratifying patient subpopulations for optimal postoperative follow-up. The aim of this systematic review and meta-analysis was to investigate the initial recurrence patterns of PDAC and to correlate them with clinicopathological factors. METHODS: MEDLINE and Web of Science databases were searched systematically for studies reporting first recurrence patterns after PDAC resection. Data were extracted from the studies selected for inclusion. Pooled odds ratios (ORs) and 95 per cent confidence intervals were calculated to determine the clinicopathological factors related to the recurrence sites. The weighted average of median overall survival was calculated. RESULTS: Eighty-nine studies with 17 313 patients undergoing PDAC resection were included. The weighted median rates of initial recurrence were 20·8 per cent for locoregional sites, 26·5 per cent for liver, 11·4 per cent for lung and 13·5 per cent for peritoneal dissemination. The weighted median overall survival times were 19·8 months for locoregional recurrence, 15·0 months for liver recurrence, 30·4 months for lung recurrence and 14·1 months for peritoneal dissemination. Meta-analysis revealed that R1 (direct) resection (OR 2·21, 95 per cent c.i. 1·12 to 4·35), perineural invasion (OR 5·19, 2·79 to 9·64) and positive peritoneal lavage cytology (OR 5·29, 3·03 to 9·25) were significantly associated with peritoneal dissemination as initial recurrence site. Low grade of tumour differentiation was significantly associated with liver recurrence (OR 4·15, 1·71 to 10·07). CONCLUSION: Risk factors for recurrence patterns after surgery could be considered for specific surveillance and treatments for patients with pancreatic cancer.

ANTECEDENTES: El mapeo del patrón de recidiva inicial tras la resección de un adenocarcinoma ductal pancreático (pancreatic ductal adenocarcinoma, PDAC) podría ayudar a estratificar subpoblaciones de pacientes para un seguimiento postoperatorio óptimo. El objetivo de esta revisión sistemática con metaanálisis fue investigar los patrones de recidiva inicial de PDAC y correlacionarlos con factores clínico-patológicos. MÉTODOS: Se realizaron búsquedas sistemáticas en las bases de datos MEDLINE y Web of Science para seleccionar estudios que presentaran información sobre los patrones de recidiva inicial después de la resección del PDAC. Se extrajeron los datos de los estudios seleccionados para su inclusión en el metaanálisis. Se calcularon las razones de oportunidades agrupadas (pooled odds ratio, OR) y los i.c. del 95% para definir los factores clínico-patológicos relacionados con las localizaciones de la recidiva. Se estimó el promedio ponderado de la mediana de la supervivencia global. RESULTADOS: Se incluyeron 89 estudios con 17.313 pacientes a los que se realizó una resección por PDAC. Las tasas medias ponderadas de las localizaciones de la recidiva inicial fueron del 20,8% para la locorregional, 26,5% para las hepáticas, 11,4% para el pulmón y 13,5% para la diseminación peritoneal. La mediana ponderada de supervivencia global fue de 19,8 meses (locorregional), 15,0 meses (hígado), 30,4 meses (pulmón) y 14,1 meses (diseminación peritoneal). El metaanálisis demostró que la resección R1 (inicial) (OR 2,21, i.c. del 95% 1,12-4,35), la invasión perineural (OR 5,19; i.c. del 95% 2,79-9,64) y la positividad de la citología del lavado peritoneal (OR 5,29; i.c. del 95% 3,03-9,25) se asociaron significativamente con la diseminación peritoneal como localización de recidiva inicial. El bajo grado de diferenciación tumoral se asoció significativamente con la recidiva hepática (OR 4,15; i.c. del 95%: 1,71-10,07). CONCLUSIÓN: Se podrían tener en cuenta estos factores de riesgo de los patrones de recidiva tras la cirugía para realizar un seguimiento y tratamiento específicos en pacientes con cáncer de páncreas.

Systematic review of the quantity and quality of randomized clinical trials in pancreatic surgery.

BACKGROUND: RCTs are considered the reference standard in clinical research. However, surgical RCTs pose specific challenges and therefore numbers have been lower than those for randomized trials of medical interventions. In addition, surgical trials have often been associated with poor methodological quality. The objective of this study was to evaluate the evolution of quantity and quality of RCTs in pancreatic surgery and to identify evidence gaps. METHODS: PubMed, CENTRAL and Web of Science were searched systematically. Predefined data were extracted and organized in a database. Quantity and quality were compared for three intervals of the study period comprising more than three decades. Evidence maps were constructed to identify gaps in evidence. RESULTS: The search yielded 8210 results, of which 246 trials containing data on 26 154 patients were finally included. The number of RCTs per year increased continuously from a mean of 2·8, to 5·7 and up to 13·1 per year over the three intervals of the study. Most trials were conducted in Europe (46·3 per cent), followed by Asia (35·0 per cent) and North America (14·2 per cent). Overall, the quality of RCTs was moderate; however, with the exception of blinding, all domains of the Cochrane risk-of-bias tool improved significantly in the later part of the study. Evidence maps showed lack of evidence from RCTs for operations other than pancreatoduodenectomy and for specific diseases such as neuroendocrine neoplasms or intraductal papillary mucinous neoplasms. CONCLUSION: The quantity and quality of RCTs in pancreatic surgery have increased. Evidence mapping showed gaps for specific procedures and diseases, indicating priorities for future research.

Validation of at least 1 mm as cut-off for resection margins for pancreatic adenocarcinoma of the body and tail.

BACKGROUND: The definition of resection margin (R) status in pancreatic cancer is under debate. Although a margin of at least 1 mm is an independent predictor of survival after resection for pancreatic head cancer, its relevance to pancreatic body and tail cancers remains unclear. This study aimed to validate R status based on a 1-mm tumour-free margin as a prognostic factor for resected adenocarcinoma involving the pancreatic body and tail. METHODS: Patients who underwent distal or total pancreatectomy for adenocarcinomas of the pancreatic body and tail between January 2006 and December 2014 were identified from a prospective database. Resection margins were evaluated using a predefined cut-off of 1 mm. Rates of R0, R1 with invasion within 1 mm of the margin (R1 less than 1 mm), and R1 with direct invasion of the resection margin (R1 direct) were determined, and overall survival in each group assessed by Kaplan-Meier analysis. Univariable and multivariable Cox regression analyses were performed to identify predictors of survival. RESULTS: R0 resection was achieved in 107 (23·5 per cent) and R1 in 348 (76·5 per cent) of 455 patients. Among R1 resections, invasion within 1 mm of the margin was found in 104 (22·9 per cent) and direct invasion in 244 (53·6 per cent). The R0 rate was 28·9 per cent after distal and 18·6 per cent after total pancreatectomy. In the total cohort, median survival times for patients with R0, R1 (less than 1 mm) and R1 (direct) status were 62·4, 24·6 and 17·2 months respectively, with 5-year survival rates of 52·6, 16·8 and 13·0 per cent (P < 0·001). In patients who received adjuvant chemotherapy, respective median survival times were 68·6, 32·8 and 21·4 months, with 5-year survival rates of 56, 22 and 16·0 per cent (P < 0·001). In multivariable analysis, R status was independently associated with survival. CONCLUSION: A cut-off of at least 1 mm for evaluation of resection margins is an independent determinant of survival after resection of adenocarcinomas of the pancreatic body and tail.

Meta-analysis of delayed gastric emptying after pylorus-preserving versus pylorus-resecting pancreatoduodenectomy.

BACKGROUND: Delayed gastric emptying (DGE) is a frequent complication after pylorus-preserving pancreatoduodenectomy. Recent studies have suggested that resection of the pylorus is associated with decreased rates of DGE. However, superiority of pylorus-resecting pancreatoduodenectomy was not shown in a recent RCT. This meta-analysis summarized evidence of the effectiveness and safety of pylorus-preserving compared with pylorus-resecting pancreatoduodenectomy. METHODS: RCTs and non-randomized studies comparing outcomes of pylorus-preserving and pylorus-resecting pancreatoduodenectomy were searched systematically in MEDLINE, Web of Science and CENTRAL. Random-effects meta-analyses were performed and the results presented as weighted odds ratios (ORs) or mean differences with their corresponding 95 per cent confidence intervals. Subgroup analyses were performed to account for interstudy heterogeneity between RCTs and non-randomized studies. RESULTS: Three RCTs and eight non-randomized studies with a total of 992 patients were included. Quantitative synthesis across all studies showed superiority for pylorus-resecting pancreatoduodenectomy regarding DGE (OR 2·71, 95 per cent c.i. 1·48 to 4·96; P = 0·001) and length of hospital stay (mean difference 3·26 (95 per cent c.i. -1·04 to 5·48) days; P = 0·004). Subgroup analyses including only RCTs showed no significant statistical differences between the two procedures regarding DGE, and for all other effectiveness and safety measures. CONCLUSION: Pylorus-resecting pancreatoduodenectomy is not superior to pylorus-preserving pancreatoduodenectomy for reducing DGE or other relevant complications.

Staging of pancreatic cancer based on the number of positive lymph nodes.

BACKGROUND: The International Study Group on Pancreatic Surgery has stated that at least 12 lymph nodes should be evaluated for staging of pancreatic cancer. The aim of this population-based study was to evaluate whether the number of positive lymph nodes refines staging. METHODS: Patients who underwent pancreatectomy for stage I-II pancreatic cancer between 2004 and 2012 were identified from the Surveillance, Epidemiology, and End Results database. The predictive value of the number of positive lymph nodes for survival was assessed by generalized receiver operating characteristic (ROC) curve analysis and propensity score-adjusted Cox regression analysis. RESULTS: Some 5036 patients were included, with a median of 18 (i.q.r. 15-24) lymph nodes examined. Positive lymph nodes were found in 3555 patients (70·6 per cent). The median duration of follow-up was 15 (i.q.r. 8-28) months. ROC curve analysis revealed that two positive lymph nodes best discriminated overall survival. Patients with one or two positive lymph nodes (pN1a) and those with three or more positive lymph nodes (pN1b) had an increased risk of overall mortality compared with patients who were node-negative (pN0): hazard ratio (HR) 1·47 (95 per cent c.i. 1·33 to 1·64) and HR 2·01 (1·82 to 2·22) respectively. These findings were confirmed by propensity score-adjusted Cox regression analysis. The 5-year overall survival rates were 39·8 (95 per cent c.i. 36·5 to 43·3) per cent for patients with pN0, 21·0 (18·6 to 23·6) per cent for those with pN1a and 11·4 (9·9 to 13·3) per cent for patients with pN1b disease. CONCLUSION: The number of positive lymph nodes in the resection specimen is a prognostic factor in patients with pancreatic cancer.

Meta-analysis of prophylactic abdominal drainage in pancreatic surgery.

BACKGROUND: Intra-abdominal drains are frequently used after pancreatic surgery whereas their benefit in other gastrointestinal operations has been questioned. The objective of this meta-analysis was to compare abdominal drainage with no drainage after pancreatic surgery. METHODS: PubMed, the Cochrane Library and Web of Science electronic databases were searched systematically to identify RCTs comparing abdominal drainage with no drainage after pancreatic surgery. Two independent reviewers critically appraised the studies and extracted data. Meta-analyses were performed using a random-effects model. Odds ratios (ORs) were calculated to aggregate dichotomous outcomes, and weighted mean differences for continuous outcomes. Summary effect measures were presented together with their 95 per cent confidence intervals. RESULTS: Some 711 patients from three RCTs were included. The 30-day mortality rate was 2·0 per cent in the drain group versus 3·4 per cent after no drainage (OR 0·68, 95 per cent c.i. 0·26 to 1·79; P = 0·43). The morbidity rate was 65·6 per cent in the drain group and 62·0 per cent in the no-drain group (OR 1·17, 0·86 to 1·60; P = 0·31). Clinically relevant pancreatic fistulas were seen in 11·5 per cent of patients in the drain group and 9·5 per cent in the no-drain group. Reinterventions, intra-abdominal abscesses and duration of hospital stay also showed no significant difference between the two groups. CONCLUSION: Pancreatic resection with, or without abdominal drainage results in similar rates of mortality, morbidity and reintervention.

Incidence, risk factors and clinical implications of chyle leak after pancreatic surgery.

BACKGROUND: Chyle leak is a well known but poorly characterized complication after pancreatic surgery. Available data on incidence, risk factors and clinical significance of chyle leak are highly heterogeneous. METHODS: For this cohort study all patients who underwent pancreatic surgery between January 2008 and December 2012 were identified from a prospective database. Chyle leak was defined as any drainage output with triglyceride content of 110 mg/dl or more. Risk factors for chyle leak were assessed by univariable and multivariable analyses. The clinical relevance of chyle leak was evaluated using hospital stay and resolution by 14 days for short-term outcome and overall survival for long-term outcome. RESULTS: Chyle leak developed in 346 (10·4 per cent) of 3324 patients. Pre-existing diabetes, resection for malignancy, distal pancreatectomy, duration of surgery 180 min or longer, and concomitant pancreatic fistula or abscess were independent risk factors for chyle leak. Both isolated chyle leak and coincidental chyle leak (with other intra-abdominal complications) were associated with prolonged hospital stay. Some 178 (87·7 per cent) of 203 isolated chyle leaks and 90 (70·3 per cent) of 128 coincidental chyle leaks resolved with conservative management within 14 days. Initial and maximum drainage volumes were associated with duration of hospital stay and success of therapy by 14 days. Impact on survival was restricted to chyle leaks that persisted at 14 days in patients with cancer undergoing palliative surgery. CONCLUSION: Chyle leak is a relevant complication, with an incidence of more than 10 per cent after pancreatic surgery, and has a major impact on hospital stay. Drainage volume is associated with hospital stay and success of therapy.