Benchmarking outcomes for distal pancreatectomy: critical evaluation of four multicenter studies

BACKGROUND

Benchmarking is a validated tool for outcome assessment and international comparison of best achievable surgical outcomes. The methodology is increasingly applied in pancreatic surgery and the aim of the review was to critically compare available benchmark studies evaluating distal pancreatectomy (DP).

METHODS

A literature search of English articles reporting on benchmarking DP was conducted of the electronic databases MEDLINE and Web of Science (until April 2023). Studies on open (ODP), laparoscopic (LDP), and robotic DP (RDP) were included.

RESULTS

Four retrospective multicenter studies were included. Studies reported on outcomes of minimally invasive DP only (n = 2), ODP and LDP (n = 1), and RDP only (n = 1). Either the Achievable Benchmark of Care™ method or the 75th percentile from the median was selected to define benchmark cutoffs. Robust and reproducible benchmark values were provided by the four studies for intra- and postoperative short-term outcomes.

CONCLUSION

Benchmarking DP is a valuable tool for obtaining internationally accepted reference outcomes for open and minimally invasive DP approaches with only minor variances in four international cohorts. Benchmark cutoffs allow for outcome comparisons between institutions, surgeons, and to monitor the introduction of novel minimally invasive DP techniques.

Optimization of anastomotic technique and gastric conduit perfusion with hyperspectral imaging and machine learning in an experimental model for minimally invasive esophagectomy

INTRODUCTION

Esophagectomy is the mainstay of esophageal cancer treatment, but anastomotic insufficiency related morbidity and mortality remain challenging for patient outcome. Therefore, the objective of this work was to optimize anastomotic technique and gastric conduit perfusion with hyperspectral imaging (HSI) for total minimally invasive esophagectomy (MIE) with linear stapled anastomosis.

MATERIAL AND METHODS

A live porcine model (n = 58) for MIE was used with gastric conduit formation and simulation of linear stapled side-to-side esophagogastrostomy. Four main experimental groups differed in stapling length (3 vs. 6 cm) and simulation of anastomotic position on the conduit (cranial vs. caudal). Tissue oxygenation around the anastomotic simulation site was evaluated using HSI and was validated with histopathology.

RESULTS

The tissue oxygenation (ΔStO₂) after the anastomotic simulation remained constant only for the short stapler in caudal position (-0.4 ± 4.4%, n.s.) while it was impaired markedly in the other groups (short-cranial: -15.6 ± 11.5%, p = 0.0002; long-cranial: -20.4 ± 7.6%, p = 0.0126; long-caudal: -16.1 ± 9.4%, p < 0.0001). Tissue samples from avascular stomach as measured by HSI showed correspondent eosinophilic pre-necrotic changes in 35.7 ± 9.7% of the surface area.

CONCLUSION

Tissue oxygenation at the site of anastomotic simulation of the gastric conduit during MIE is influenced by stapling technique. Optimal oxygenation was achieved with a short stapler (3 cm) and sufficient distance of the simulated anastomosis to the cranial end of the gastric conduit. HSI tissue deoxygenation corresponded to histopathologic necrotic tissue changes. The experimental model with HSI and ML allow for systematic optimization of gastric conduit perfusion and anastomotic technique while clinical translation will have to be proven.

Meta-analysis of randomized controlled trials and individual patient data comparing minimally invasive with open oesophagectomy for cancer

BACKGROUND

Minimally invasive oesophagectomy (MIO) for oesophageal cancer may reduce surgical complications compared with open oesophagectomy. MIO is, however, technically challenging and may impair optimal oncological resection. The aim of the present study was to assess if MIO for cancer is beneficial.

METHODS

A systematic literature search in MEDLINE, Web of Science and CENTRAL was performed and randomized controlled trials (RCTs) comparing MIO with open oesophagectomy were included in a meta-analysis. Survival was analysed using individual patient data. Random-effects model was used for pooled estimates of perioperative effects.

RESULTS

Among 3219 articles, six RCTs were identified including 822 patients. Three-year overall survival (56 (95 per cent c.i. 49 to 62) per cent for MIO versus 52 (95 per cent c.i. 44 to 60) per cent for open; P = 0.54) and disease-free survival (54 (95 per cent c.i. 47 to 61) per cent versus 50 (95 per cent c.i. 42 to 58) per cent; P = 0.38) were comparable. Overall complication rate was lower for MIO (odds ratio 0.33 (95 per cent c.i. 0.20 to 0.53); P < 0.010) mainly due to fewer pulmonary complications (OR 0.44 (95 per cent c.i. 0.27 to 0.72); P < 0.010), including pneumonia (OR 0.41 (95 per cent c.i. 0.22 to 0.77); P < 0.010).

CONCLUSION

MIO for cancer is associated with a lower risk of postoperative complications compared with open resection. Overall and disease-free survival are comparable for the two techniques.

LAY SUMMARY

Oesophagectomy for cancer is associated with a high risk of complications. A minimally invasive approach might be less traumatic, leading to fewer complications and may also improve oncological outcome. A meta-analysis of randomized controlled trials comparing minimally invasive to open oesophagectomy was performed. The analysis showed that the minimally invasive approach led to fewer postoperative complications, in particular, fewer pulmonary complications. Survival after surgery was comparable for the two techniques.

[Quality of indications in bariatric surgery]

Bariatric and metabolic surgery is increasingly being utilized in Germany and also worldwide. Due to the increased perioperative risk compared to non-obese patients, a detailed and accurate preoperative assessment of the patient is pivotal to improve postoperative and long-term outcomes. The indications for bariatric surgery have shifted in recent years from a certain body mass index (BMI) to comorbidity-based indications. In 2018 the German S3 guidelines for metabolic surgery defined the indications for bariatric surgery as well as the preoperative assessment. The indications for bariatric metabolic operations should be assessed by an interdisciplinary team consisting of surgeons, internists, diabetologists, psychologists and dietitians. It is paramount that surgeon and patient define realistic goals of these operations. Also, the different types of bariatric operation and their long-term consequences should be discussed. Additionally, a thorough endocrinological assessment by an internist or diabetologist with respect to relevant comorbidities of obesity as well as the adjustment of existing therapies are important. An assessment by a mental health professional is also mandatory; however, psychological comorbidities are not a contraindication as long as the patient is being treated and the disease is controlled. A preoperative short-term high-protein and low-carbohydrate fluid nutrition helps to reduce the risk of postoperative complications, especially for patients with a high BMI. A preoperative weight loss in the sense of a mandatory loss of a defined proportion of the body weight is not useful.

[Metabolic surgery]

In recent years the surgical treatment of metabolic diseases has become established as an effective alternative to conservative treatment. The new S3 guidelines address these changes and give clear indications for obesity surgery. One of the core points of the new guidelines is the differentiation between obesity surgery and metabolic surgery. In obesity surgery the primary aim of treatment is weight loss whereas for metabolic indications the aim is an improvement of comorbidities independent of the body mass index (BMI). With respect to the selection of procedures sleeve gastrectomy (SG) and the traditional Roux-en-Y gastric bypass (RYGB) can be used as safe and evidence-based operative procedures. The RYGB has better metabolic effects but higher complication and reintervention rates. More recent procedures, such as the one anastomosis gastric bypass (OAGB) and single anastomosis duodeno-ileal (SADI) bypass possibly have slightly stronger metabolic effects, however, the risk of malnutrition and vitamin deficiency is higher.

Diet-dependent function of the extracellular matrix proteoglycan Lumican in obesity and glucose homeostasis

Objective

Extracellular matrix remodeling is required for adipose expansion under increased caloric intake. In turn, inhibited expandability due to aberrant collagen deposition promotes insulin resistance and progression towards the metabolic syndrome. An emerging role for the small leucine-rich proteoglycan Lumican in metabolically driven nonalcoholic fatty liver disease sparks an interest in further understanding its role in diet-induced obesity and metabolic complications.

Methods

Whole body ablation of Lumican (Lum^−/−) gene and adeno-associated virus-mediated over-expression were used in combination with control or high fat diet to assess energy balance, glucose homeostasis as well as adipose tissue health and remodeling.

Results

Lumican was found to be particularly enriched in the stromal cells isolated from murine gonadal white adipose tissue. Likewise murine and human visceral fat showed a robust increase in Lumican as compared to fat from the subcutaneous depot. Lumican null female mice exhibited moderately increased fat mass, decreased insulin sensitivity and increased liver triglycerides in a diet-dependent manner. These changes coincided with inflammation in adipose tissue and no overt effects in adipose expandability, i.e. adipocyte formation and hypertrophy. Lumican over-expression in visceral fat and liver resulted in improved insulin sensitivity and glucose clearance.

Conclusions

These data indicate that Lumican may represent a functional link between the extracellular matrix, glucose homeostasis, and features of the metabolic syndrome.

•

The extracellular matrix proteoglycan Lumican (Lum) is particularly enriched in stromal cells within white adipose tissue.

•

Visceral fat from obese patients displays increased levels of Lum compared to subcutaneous fat.

•

Lum-Ko female mice exhibit decreased insulin sensitivity and increased triglycerides upon high-fat diet (HFD) feeding.

•

Lum-Ko female mice on HFD have increased inflammation in white fat in the absence of overt effects on adipocyte formation.

•

· Lum over-expression in visceral fat and liver resulted in improved insulin sensitivity and glucose clearance.

Meta-analysis of metabolic surgery versus medical treatment for microvascular complications in patients with type 2 diabetes mellitus

Background

This study aimed to examine the effect of metabolic surgery on pre-existing and future microvascular complications in patients with type 2 diabetes mellitus (T2DM) in comparison with medical treatment. Although metabolic surgery is the most effective treatment for obese patients with T2DM regarding glycaemic control, it is unclear whether the incidence or severity of microvascular complications is reduced.

Methods

A systematic literature search was performed in MEDLINE, Embase, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL) with no language restrictions, looking for RCTs, case–control trials and cohort studies that assessed the effect of metabolic surgery on the incidence of microvascular diabetic complications compared with medical treatment as control. The study was registered in the International prospective register of systematic reviews (CRD42016042994).

Results

The literature search yielded 1559 articles. Ten studies (3 RCTs, 7 controlled clinical trials) investigating 17 532 patients were included. Metabolic surgery reduced the incidence of microvascular complications (odds ratio 0·26, 95 per cent c.i. 0·16 to 0·42; P &lt; 0·001) compared with medical treatment. Pre-existing diabetic nephropathy was strongly improved by metabolic surgery versus medical treatment (odds ratio 15·41, 1·28 to 185·46; P = 0·03).

Conclusion

In patients with T2DM, metabolic surgery prevented the development of microvascular complications better than medical treatment. Metabolic surgery improved pre-existing diabetic nephropathy compared with medical treatment.

Meta-analysis of immunonutrition in major abdominal surgery

Background

The objective of this study was to evaluate the potential benefits of immunonutrition in major abdominal surgery with special regard to subgroups and influence of bias.

Methods

A systematic literature search from January 1985 to July 2015 was performed in MEDLINE, Embase and CENTRAL. Only RCTs investigating immunonutrition in major abdominal surgery were included. Outcomes evaluated were mortality, overall complications, infectious complications and length of hospital stay. The influence of different domains of bias was evaluated in sensitivity analyses. Evidence was rated according to the GRADE Working Group grading of evidence.

Results

A total of 83 RCTs with 7116 patients were included. Mortality was not altered by immunonutrition. Taking all trials into account, immunonutrition reduced overall complications (odds ratio (OR) 0·79, 95 per cent c.i. 0·66 to 0·94; P = 0·01), infectious complications (OR 0·58, 0·51 to 0·66; P &lt; 0·001) and shortened hospital stay (mean difference –1·79 (95 per cent c.i. –2·39 to –1·19) days; P &lt; 0·001) compared with control groups. However, these effects vanished after excluding trials at high and unclear risk of bias. Publication bias seemed to be present for infectious complications (P = 0·002). Non-industry-funded trials reported no positive effects for overall complications (OR 1·13, 0·88 to 1·46; P = 0·34), whereas those funded by industry reported large effects (OR 0·66, 0·48 to 0·91; P = 0·01).

Conclusion

Immunonutrition after major abdominal surgery did not seem to alter mortality (GRADE: high quality of evidence). Immunonutrition reduced overall complications, infectious complications and shortened hospital stay (GRADE: low to moderate). The existence of bias lowers confidence in the evidence (GRADE approach).

[The way from cost approval to bariatric surgery : Analysis of resource utilization in a maximum care hospital]

BACKGROUND

Morbid obesity is a medical and economic challenge. Patients who have the indications for bariatric surgery face a long way from the first visit until surgery and a high utilization of resources is required.

OBJECTIVES

The present study aimed to evaluate labor costs and labor time required to supervise obese patients from their first visit until preparation of a bariatric report to ask for cost acceptance of bariatric surgery from their health insurance. In addition, the reasons for not receiving bariatric surgery after receiving cost acceptance from the health insurance were evaluated.

MATERIAL AND METHODS

Patients who had indications for bariatric surgery according to the S3 guidelines between 2012 and 2013, were evaluated regarding labor costs and labor time of the process from the first visit until receiving cost acceptance from their health insurance. Furthermore, body mass index (BMI), age, sex, Edmonton Obesity Staging System (EOSS) stage and comorbidities were evaluated. Patients who had not received surgery up to December 2015 were contacted via telephone to ask for the reasons.

RESULTS

In the present study 176 patients were evaluated (110 females, 62.5%). Until preparation of a bariatric report the patients required an average of 2.7 combined visits in the department of surgery with the department of nutrition, 1.7 visits in the department of psychosomatic medicine, 1.5 separate visits in the department of nutrition and 1.4 visits in the department of internal medicine. Average labor costs from the first visit until the bariatric survey were 404.90 ± 117.00 euros and 130 out of 176 bariatric reports were accepted by the health insurance (73.8%). For another 40 patients a second bariatric survey was made and 20 of these (50%) were accepted, which results in a total acceptance rate of 85.2% (150 out of 176). After a mean follow-up of 2.8 ± 1.1 years only 93 out of 176 patients had received bariatric surgery (53.8%). Of these 16 had received acceptance of surgery by their health insurance only after a second bariatric survey.

CONCLUSION

A large amount of labor and financial resources are required for treatment of obese patients from first presentation up to bariatric surgery. The cost-benefit calculation of an obesity center needs to include that approximately one half of the patients do not receive surgery within more than 2.5 years.

[Clinical evidence for metabolic surgery]

The metabolic effect of bariatric surgery is well-established and is considered to be self-evident in morbidly obese patients with a body mass index (BMI) > 40 kg/m(2). Metabolic surgery performed on patients with obesity grades II (BMI 35-40 kg/m(2)) and I (BMI 30-35 kg/m(2)) according to the World Health Organization (WHO) has increased in recent years; however, the indications for metabolic surgery in obesity grades I and II are currently under debate due to insufficient evidence. In the last 5 years several highly qualified randomized clinical trials have been published which evaluated the effect of metabolic surgery in patients with obesity grades I and II in comparison to conservative therapy. Based on these data the efficacy of metabolic surgery in short-term follow-up (12-36 months) is unquestionable when compared to conservative therapy according to the current guidelines. Besides improved glycemic control and remission of diabetes, metabolic surgery has the potential to have a positive influence on diabetic complications, such as diabetic retinopathy, nephropathy and polyneuropathy, as well as on comorbidities, such as arterial hypertension and dyslipidemia. Future clinical trials should address the long-term (> 36 months) effects of metabolic surgery, patient selection criteria and choice of procedure.

Polypropylene, polyester or polytetrafluoroethylene-is there an ideal material for mesh augmentation at the esophageal hiatus? Results from an experimental study in a porcine model

PURPOSE

Knowledge about the influence of underlying biomaterial on behavior of surgical meshes at the esophageal hiatus is rare, but essential for safe and effective hiatal hernia surgery. This study aimed to characterize the influence of polymer material on mesh behavior at the hiatus.

METHODS

24 pigs in three groups of eight underwent implantation of either polypropylene (PP), polyester (PET) or polytetrafluoroethylene (PTFE) mesh placed circularly at the esophageal hiatus. After 8 weeks, necropsy and measurements were performed evaluating mesh deformation, adhesion formation, fixation of the esophagogastric junction and mesh position. Foreign body reaction was assessed by mononuclear cell count and immunostaining of Ki-67. Tissue integration was evaluated by immunostaining of type I and type III collagen fibers.

RESULTS

Mesh shrinkage was the highest for PTFE, lower for PP and the lowest for PET (34.9 vs. 19.8 vs. 12.1 %; p = 0.002). Mesh aperture for the esophagus showed an enlargement within all groups, which was highest for PTFE compared to PP and PET (100.8 vs. 47.0 vs. 35.9 %; p = 0.001). The adhesion score was highest for PP, lower for PTFE and the lowest for PET (11.0 vs. 9.5 vs. 5.0; p = 0.001) and correlated positively with the score of esophagogastric fixation (r s = 0.784, p < 0.001). No mesh migration, erosion or stenosis of the esophagus occurred. Evaluation of foreign body reaction and tissue integration showed no significant differences.

CONCLUSIONS

In this experimental setting, PP-meshes showed the most appropriate characteristics for augmentation at the hiatus. Due to solid fixation of the esophagogastric junction and low shrinkage tendency, PP-meshes may be effective in preventing hiatal hernia recurrence. The use of PTFE-mesh at the hiatus may be disadvantageous due to high shrinkage rates and correlating enlargement of the aperture for the esophagus.

Serial lactate and admission SOFA scores in trauma: an analysis of predictive value in 724 patients with and without traumatic brain injury

OBJECTIVE

Arterial lactate, base excess (BE), lactate clearance, and Sequential Organ Failure Assessment (SOFA) score have been shown to correlate with outcome in severely injured patients. The goal of the present study was to separately assess their predictive value in patients suffering from traumatic brain injury (TBI) as opposed to patients suffering from injuries not related to the brain.

MATERIALS AND METHODS

A total of 724 adult trauma patients with an Injury Severity Score (ISS) ≥ 16 were grouped into patients without TBI (non-TBI), patients with isolated TBI (isolated TBI), and patients with a combination of TBI and non-TBI injuries (combined injuries). The predictive value of the above parameters was then analyzed using both uni- and multivariate analyses.

RESULTS

The mean age of the patients was 39 years (77 % males), with a mean ISS of 32 (range 16-75). Mortality ranged from 14 % (non-TBI) to 24 % (combined injuries). Admission and serial lactate/BE values were higher in non-survivors of all groups (all p < 0.01), but not in patients with isolated TBI. Admission SOFA scores were highest in non-survivors of all groups (p = 0.023); subsequently septic patients also showed elevated SOFA scores (p < 0.01), except those with isolated TBI. In this group, SOFA score was the only parameter which showed significant differences between survivors and non-survivors. Receiver operating characteristic (ROC) analysis revealed lactate to be the best overall predictor for increased mortality and further septic complications, irrespective of the leading injury.

CONCLUSION

Lactate showed the best performance in predicting sepsis or death in all trauma patients except those with isolated TBI, and the differences were greatest in patients with substantial bleeding. Following isolated TBI, SOFA score was the only parameter which could differentiate survivors from non-survivors on admission, although the SOFA score, too, was not an independent predictor of death following multivariate analysis.