Comparative cell culture effects of shape memory metal (Nitinol), nickel and titanium: a biocompatibility estimation.

Nitinol is an equiatomic alloy of nickel and titanium which has been attracting increasing interest in the field of biomedical engineering. To quantify toxicity as a preliminary evaluation of biocompatibility, inhibition of mitosis in human fibroblasts in tissue cultures exposed to test materials is an accepted screening method, although a dose-effect relationship had never been investigated. In this experiment, the effect of an increasing dose exposure to Nitinol, nickel or titanium on human fibroblasts in cell cultures was tested in subgroups in comparison with a control group. The results showed that nickel induces a significant (p < or = 0.05) inhibition of mitosis in human fibroblasts, whereas no significant effects of this kind were found for titanium or Nitinol. According to the results of these studies, Nitinol is to be considered in this respect biocompatible and comparable to titanium, which would seem to justify application as a surgical implant.     

ASO Visual Abstract: The Landmark Series—Minimally Invasive Pancreatic Resection

Annals of Surgical Oncology -     

Early oral feeding after pancreatoduodenectomy enhances recovery without increasing morbidity

Objective

The aim of this study was to evaluate whether a change in the routine feeding strategy applied after pancreatoduodenectomy (PD) from nasojejunal tube (NJT) feeding to early oral feeding improved clinical outcomes.

Methods

An observational cohort study was performed in 102 consecutive patients undergoing PD. In period 1 (n = 51, historical controls), the routine postoperative feeding strategy was NJT feeding. This was changed to a protocol of early oral feeding with on-demand NJT feeding in period 2 (n = 51, consecutive prospective cohort). The primary outcome was time to resumption of adequate oral intake.

Results

The baseline characteristics of study subjects in both periods were comparable. In period 1, 98% (n = 50) of patients received NJT feeding, whereas in period 2, 53% (n = 27) of patients did so [for delayed gastric empting (DGE) (n = 20) or preoperative malnutrition (n = 7)]. The time to resumption of adequate oral intake significantly decreased from 12 days in period 1 to 9 days in period 2 (P = 0.015), and the length of hospital stay shortened from 18 days in period 1 to 13 days in period 2 (P = 0.015). Overall, there were no differences in the incidences of complications of Clavien–Dindo Grade III or higher, DGE, pancreatic fistula, postoperative haemorrhage and mortality between the two periods.

Conclusions

The introduction of an early oral feeding strategy after PD reduced the time to resumption of adequate oral intake and length of hospital stay without negatively impacting postoperative morbidity.     

Surgical treatment of acute pancreatitis

Background

Acute pancreatitis remains an unpredictable, potentially lethal disease with significant morbidity and mortality rates. New insights in the pathophysiology of acute pancreatitis have changed management concepts. In the first phase, characterized by a systemic inflammatory response syndrome, organ failure, not related to infection but rather to severe inflammation, dominates the focus of treatment. In the second phase, secondary infectious complications largely determine the clinical outcome. As infection is associated with increased mortality in acute pancreatitis, numerous prophylactic strategies have been explored in the past two decades.

Purpose

This review describes the strategies that have been developed to lower the infection rate, in an attempt to lower mortality. Antibiotic prophylaxis has been the subject of many RCT’s without showing convincing evidence of their efficacy. Probiotics, although theoretically capable of lowering the rate of infection, also had no effect on infectious complications, and consequently, no effective strategy to lower the rate of infectious complications is currently available. In the second part of this review, new approaches for necrosectomy that have been designed by different centers around the world are discussed. All the interventional techniques have in common their aim to lower the invasive character, hypothesizing that lowering the surgical trauma will improve survival and lower complication rates. Recent advances include postponing intervention as a strategy to facilitate necrosectomy and improve prognosis and the “step-up approach” in case of infected necrosis. The step-up approach includes percutaneous catheter drainage as the first step, to be followed by necrosectomy, either through a minimally invasive approach or by open necrosectomy, as the next step.

Conclusions

All attempts to develop treatment strategies to lower the infection rate in acute pancreatitis have failed. Accumulating evidence is emerging to show that the combination of centralization, the use of catheter drainage as the first step of invasive treatment, and the development of minimally invasive techniques, improve the outlook for patients with infected necrosis. It is uncertain at this point in time as to which of the three effects is dominant in the improvement of prognosis.     

Endoscopic Management of Infected Necrotizing Pancreatitis: an Evidence-Based Approach

Purpose of Review

Endoscopic management of infected necrotizing pancreatitis has evolved rapidly over the past years and there have been interesting innovations in this field. This review provides an update on the most recently published literature regarding endoscopic management of infected necrotizing pancreatitis.

Recent Findings

A recent randomized trial demonstrated no difference in mortality and major morbidity between endoscopic and surgical step-up treatment of infected necrotizing pancreatitis. However, endoscopic therapy resulted in shorter hospital stay and less pancreatic fistulas. Various innovations have been investigated with the aim to further optimize endoscopic therapy, in particular lumen-apposing metal stents. While major stent-related complications were also reported, findings from recent studies indicated that their use was associated with higher resolution rates of walled-off necrosis compared to double-pigtail stents. Other innovations, such as the multiple gateway technique and dual-modality mode, can be considered for treatment of particular cases. Furthermore, research suggests that irrigation of walled-off necrosis can be performed by using a nasocystic tube and discontinuation of proton-pump inhibitors may be considered.

Summary

Endoscopic treatment should be the preferred treatment modality in patients with infected necrotizing pancreatitis who are eligible for endoscopic drainage. Although data suggests that lumen-apposing metal stents are superior to double-pigtail stents, prospective multicenter studies focusing on safety as well as long-term follow-up are first needed.