Recent randomized controlled trials in pancreaticoduodenectomy

Systematic review of sample size calculations and reporting in randomized controlled trials in ophthalmology over a 20-year period

PURPOSE

Randomized Controlled Trials (RCTs) are considered the gold standard for the practice of evidence-based medicine. The purpose of this study is to systematically assess the reporting of sample size calculations in ophthalmology RCTs in 5 leading journals over a 20-year period. Reviewing sample size calculations in ophthalmology RCTs will shed light on the methodological quality of RCTs and, by extension, on the validity of published results.

METHODS

The MEDLINE database was searched to identify full reports of RCTs in the journals Ophthalmology, JAMA Ophthalmology, American Journal of Ophthalmology, Investigative Ophthalmology and Visual Science, and British Journal of Ophthalmology between January and December of the years 2000, 2010 and 2020. Screening identified 559 articles out of which 289 met the inclusion criteria for this systematic review. Data regarding sample size calculation reporting and trial characteristics was extracted for each trial by independent investigators.

RESULTS

In 2020, 77.9% of the RCTs reported sample size calculations as compared with 37% in 2000 (p < 0.001) and 60.7% in 2010 (p = 0.012). Studies reporting all necessary parameters for sample size recalculation increased significantly from 17.2% in 2000 to 39.3% in 2010 and 43.0% in 2020 (p < 0.001). Reporting of funding was greater in 2020 (98.8%) compared with 2010 (89.3%) and 2000 (53.1%). Registration in a clinical trials database occurred more frequently in 2020 (94.2%) compared to 2000 (1.2%; p < 0.001) and 2010 (68%; p < 0.001). In 2020, 38.4% of studies reported different sample sizes in the online registry from the published article. Overall, the most studied area in 2000 was glaucoma (29.6% of RCTs), whereas in 2010 and 2020, it was retina (40.2 and 37.2% of the RCTs, respectively). The number of patients enrolled in a study and the number of eyes studied was significantly greater in 2020 compared to 2000 and 2010 (p < 0.001).

CONCLUSION

Sample size calculation reporting in ophthalmology RCTs has improved significantly between the years 2000 and 2020 and is comparable to other fields in medicine. However, reporting of certain parameters remains inconsistent with current publication guidelines.

Current status and perspectives of the future of pancreatic surgery: Establishment of evidence by integration of "art" and "science"

Pancreatic cancer surgery continues to be associated with a high operative morbidity rate, poor long-term survival outcomes, and various challenges in obtaining high-level evidence. Not only is the early postoperative morbidity rate high, but also late morbidity involves lifelong nutritional support for long-term survivors. Due to poor survival outcomes even after curative surgery, pancreatic surgeons have doubts about the role of surgery as the definitive treatment for pancreatic cancer. Additionally, conducting clinical trials to obtain high-level evidence in the field of pancreatic surgery is difficult, and the results have only had a moderate impact on clinical practice due to skepticism regarding their quality. Therefore, quality evidence regarding the extent of resection, mode of approach to dissection, reconstruction methods for pancreatico-enteric anastomosis, determination of resectability, timing of surgery, and the definition of the resection margin is lacking. However, numerous innovative pancreatic surgical procedures have been developed, which may aptly have been called "art" when they were first introduced, regardless of whether they subsequently were supported by scientific evidence. In this review, we provide recent examples of the integration of art and science in the field of pancreatic surgery, which illustrate how the creative ideas of pancreatic surgeons evolved into generally accepted clinical practice. Pancreatic surgeons should be considered "surgical artists," "surgical scientists," and "surgical practitioners." We look forward to more "surgical artists" educating future "surgical artists and scientists" to create a richer "spirit of innovation," leading to a more beautiful integration of art and science in the field of pancreatic surgery.

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.

Development of a composite endpoint for randomized controlled trials in pancreaticoduodenectomy

BACKGROUND

Few randomized controlled trials (RCTs) have been performed in patients undergoing pancreaticoduodenectomy (PD). An important factor contributing to this is the large number of patients needed to adequately power RCTs for relevant clinical single endpoints. A PD-specific composite endpoint (CEP) could solve this problem. The aim of the present study was to develop a PD-specific CEP, consisting of complications related to PD, allowing reduction in sample sizes and improving the ability to compare outcomes.

METHODS

PD-specific CEP components were selected after a systematic review of the literature and consensus between 25 international pancreatic surgeons. Ultimately, prospective cohorts of patients who underwent PD in two high-volume HPB centers (London, UK, and Maastricht, NL) were used to assess the event rate and effect of implementing a PD-specific CEP.

RESULTS

From a total of 18 single-component endpoints, intra-abdominal abscess, sepsis, post-PD hemorrhage, bile leakage, gastrojejunostomy leakage, leakage of the pancreatic anastomosis, delayed gastric emptying, and operative mortality within 90 days were selected to be included the PD-specific CEP. All eight components had consensus definitions and a Dindo-Clavien classification of 3 or more. The incidence of the PD-specific CEP was 24.7 % in the Maastricht cohort and 23.3 % in the London cohort. These incidence rates led to a twofold reduction in the theoretical calculated sample size for an adequately powered RCT on PD using this CEP as a primary endpoint.

CONCLUSIONS

The proposed PD-specific CEP enables clinical investigators to adequately power RCTs on PD and increases the feasibility, comparability, and utility in meta-analysis.

Delayed gastric emptying: the state of the highest level of evidence

Delayed gastric emptying (DGE) has been regarded as the most common complication after pancreaticoduodenectomy (PD). Opinions about DGE and its incidence widely vary between studies and between institutions. To crystallize current concepts of DGE we resorted to a systematic literature search of level I evidence. We found 16 randomized controlled trials (RCTs) where DGE was measured but only 4 of these trials tested methods to influence DGE (erythromycin, enteral nutrition, or antecolic duodenojejunostomy). Constant heterogeneity for the definition of DGE was observed; 13 RCTs used 6 different clinical definitions based on some form of NG tube requirement after surgery, and the 3 remaining RCTs used non-clinical objective criteria. The most common element of the clinical definitions was the need for an NG tube >10 postoperative days. Ten RCTs used some form of this definition and the reported mean incidence of DGE was 17% however the range varied from 5% to 57%. The trials with the least number of cases appeared to have the widest variation in DGE incidence. We concluded after this systematic review that the disparate opinions about DGE could not be mediated with the highest level of evidence. The studies were underpowered or compromised by a lack of homogeneity in definition and design. The incidence of DGE cannot be succinctly measured; therefore the variables that influence DGE are not understood. We can begin to make progress by using the same definition such as the recently published definition provided by the International Study Group of Pancreatic Surgery.

An easier method for performing a pancreaticojejunostomy for the soft pancreas using a fast-absorbable suture

AIM: To clarify the usefulness of a new method for performing a pancreaticojejunostomy by using a fast-absorbable suture material irradiated polyglactin 910, and a temporary stent tube for a narrow pancreatic duct with a soft pancreatic texture.

METHODS: Among 63 consecutive patients with soft pancreas undergoing a pancreaticoduodenectomy from 2003 to 2006, 35 patients were treated with a new reconstructive method. Briefly, after the pancreatic transaction, a stent tube was inserted into the lumen of the pancreatic duct and ligated with it by a fast-absorbable suture. Another tip of the stent tube was introduced into the intestinal lumen at the jejunal limb, where a purse-string suture was made by another fast-absorbable suture to roughly fix the tube. The pancreaticojejunostomy was completed by ligating two fast-absorbable sutures to approximate the ductal end and the jejunal mucosa, and by adding a rough anastomosis between the pancreatic parenchyma and the seromuscular layer of the jejunum. The initial surgical results with this method were retrospectively compared with those of the 28 patients treated with conventional duct-to-mucosa anastomosis.

RESULTS: The incidences of postoperative morbidity including pancreatic fistula were comparable between the two groups (new; 3%-17% vs conventional; 7%-14% according to the definitions). There was no mortality and re-admission. Late complications were also rarely seen.

CONCLUSION: A pancreaticojejunostomy using an irradiated polyglactin 910 suture material and a temporary stent is easy to perform and is feasible even in cases with a narrow pancreatic duct and a normal soft pancreas.