Safety and efficacy of a metal stent covered with a silicone membrane containing integrated silver particles in preventing biofilm and sludge formation in endoscopic drainage of malignant biliary obstruction: a phase 2 pilot study

BACKGROUND AND AIMS

Membrane-covered self-expandable metal stents (SEMSs) have been developed to prolong the patency of stents by reducing tissue hyperplasia or tumor ingrowth. However, their effectiveness is attenuated by stent clogging as a result of biofilm formation on the inner surface of the membrane. The aim of this pilot study was to evaluate the efficacy and safety of SEMSs covered with a silicone membrane containing integrated silver particles (Ag-P) in malignant distal biliary obstruction.

METHODS

Twenty-four patients who underwent SEMS placement because of malignant distal biliary obstruction were enrolled in this single-center pilot study. The main outcomes were technical success, clinical success, adverse events, stent patency, and survival.

RESULTS

The technical and clinical success rates were 100% and 91.7% (22 of 24), respectively. The rates of early and late adverse events were 22.7% and 36.4%, respectively. The primary reintervention rate was 27.3% (6 of 22). Only 1 case involving stent malfunction was associated with sludge impaction. Median stent patency was 179 days. During follow-up, there were no serious adverse events or mortality related to the stents or Ag-P. Serum and urine silver concentrations before and after stent placement and at 32 weeks after placement did not differ. All serum and urine silver concentrations were <3 μg/L (3 ppb) and 5 μg/L (5 ppb), respectively.

CONCLUSIONS

SEMSs covered with a silicone membrane containing integrated Ag-Ps may be effective and safe in malignant distal biliary obstruction. Stent dysfunction related to sludge impaction may be less frequent using this new stent. (Clinical Research Information Service identifier: KCT 0002310.).

Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Background

The goal of this study was to theoretically investigate the feasibility of intraductal and transgastric approaches to ultrasound-based thermal therapy of pancreatic tumors, and to evaluate possible treatment strategies.

Methods

This study considered ultrasound applicators with 1.2 mm outer diameter tubular transducers, which are inserted into the tissue to be treated by an endoscopic approach, either via insertion through the gastric wall (transgastric) or within the pancreatic duct lumen (intraductal). 8 patient-specific, 3D, transient, biothermal and acoustic finite element models were generated to model hyperthermia (n = 2) and ablation (n = 6), using sectored (210°–270°, n = 4) and 360° (n = 4) transducers for treatment of 3.3–17.0 cm³ tumors in the head (n = 5), body (n = 2), and tail (n = 1) of the pancreas. A parametric study was performed to determine appropriate treatment parameters as a function of tissue attenuation, blood perfusion rates, and distance to sensitive anatomy.

Results

Parametric studies indicated that pancreatic tumors up to 2.5 or 2.7 cm diameter can be ablated within 10 min with the transgastric and intraductal approaches, respectively. Patient-specific simulations demonstrated that 67.1–83.3% of the volumes of four sample 3.3–11.4 cm³ tumors could be ablated within 3–10 min using transgastric or intraductal approaches. 55.3–60.0% of the volume of a large 17.0 cm³ tumor could be ablated using multiple applicator positions within 20–30 min with either transgastric or intraductal approaches. 89.9–94.7% of the volume of two 4.4–11.4 cm³ tumors could be treated with intraductal hyperthermia. Sectored applicators are effective in directing acoustic output away from and preserving sensitive structures. When acoustic energy is directed towards sensitive structures, applicators should be placed at least 13.9–14.8 mm from major vessels like the aorta, 9.4–12.0 mm from other vessels, depending on the vessel size and flow rate, and 14 mm from the duodenum.

Conclusions

This study demonstrated the feasibility of generating shaped or conformal ablative or hyperthermic temperature distributions within pancreatic tumors using transgastric or intraductal ultrasound.

Thermal therapy of pancreatic tumours using endoluminal ultrasound: Parametric and patient-specific modelling

PURPOSE

The aim of this study is to investigate endoluminal ultrasound applicator configurations for volumetric thermal ablation and hyperthermia of pancreatic tumours using 3D acoustic and biothermal finite element models.

MATERIALS AND METHODS

Parametric studies compared endoluminal heating performance for varying applicator transducer configurations (planar, curvilinear-focused, or radial-diverging), frequencies (1-5 MHz), and anatomical conditions. Patient-specific pancreatic head and body tumour models were used to evaluate feasibility of generating hyperthermia and thermal ablation using an applicator positioned in the duodenal or stomach lumen. Temperature and thermal dose were calculated to define ablation (> 240 EM(43 °C)) and moderate hyperthermia (40-45 °C) boundaries, and to assess sparing of sensitive tissues. Proportional-integral control was incorporated to regulate maximum temperature to 70-80 °C for ablation and 45 °C for hyperthermia in target regions.

RESULTS

Parametric studies indicated that 1-3 MHz planar transducers are the most suitable for volumetric ablation, producing 5-8 cm(3) lesion volumes for a stationary 5-min sonication. Curvilinear-focused geometries produce more localised ablation to 20-45 mm depth from the GI tract and enhance thermal sparing (T(max) < 42 °C) of the luminal wall. Patient anatomy simulations show feasibility in ablating 60.1-92.9% of head/body tumour volumes (4.3-37.2 cm(3)) with dose < 15 EM(43 °C) in the luminal wall for 18-48 min treatment durations, using 1-3 applicator placements in GI lumen. For hyperthermia, planar and radial-diverging transducers could maintain up to 8 cm(3) and 15 cm(3) of tissue, respectively, between 40-45 °C for a single applicator placement.

CONCLUSIONS

Modelling studies indicate the feasibility of endoluminal ultrasound for volumetric thermal ablation or hyperthermia treatment of pancreatic tumour tissue.

Complications and survival associated with operative procedures in patients with unresectable pancreatic head adenocarcinoma

BACKGROUND

Unresectable tumors of the pancreatic head are encountered in up to 20% of patients taken for resection. The objective of this study was to evaluate the complications and outcome associated with palliative surgical procedures to help guide management decisions in these patients.

METHODS

Patients with pancreatic head adenocarcinoma taken to the operating room with curative intent who did not undergo pancreatectomy were evaluated.

RESULTS

From 1997 to 2013, 50 patients were explored and found be unresectable due to M1 disease (n = 27, 54.0%) or vascular invasion (n = 23, 46.0%). Among unresectable patients, 34 (68.0%) had a palliative procedure performed including double bypass (n = 13), biliary bypass (n = 7), gastrojejunostomy (n = 5), or cholecystectomy (n = 9). Complications occurred in 22 patients (44.0%), and patients who had a palliative operation had a longer hospital stay and more major complications. Overall survival was reduced in patients treated with a palliative operation.

CONCLUSIONS

Despite advancements in endoscopic palliation, operative bypasses are still commonplace in patients with unresectable pancreatic head cancer. In this study, patients treated with operative procedures had a high rate of complications without a notable improvement in outcome. These findings highlight the importance of identifying unresectable disease prior to surgery and support a selective approach to palliative operations.

The management of cancer pain

The experience of pain in cancer is widely accepted as a major threat to quality of life, and the relief of pain has emerged as a priority in oncology care. Pain is associated with both the disease as well as treatment, and management is essential from the onset of early disease through long-term survivorship or end-of-life care. Effective relief of pain is contingent upon a comprehensive assessment to identify physical, psychological, social, and spiritual aspects and as a foundation for multidisciplinary interventions. Fortunately, advances in pain treatment and in the field of palliative care have provided effective treatments encompassing pharmacological, cognitive-behavioral, and other approaches. The field of palliative care has emphasized that attention to symptoms such as pain is integral to quality cancer care.

Endoscopic ultrasound-guided neurolysis in pancreatic cancer

Abdominal pain in patients with pancreatic cancer is a common symptom that is often difficult to manage. Opioids are frequently used in an attempt to mitigate pain; however, side effects may develop. Celiac plexus neurolysis (CPN) affords effective pain control in patients with pancreatic cancer and is not associated with opioid side effects. Endoscopic ultrasound (EUS)-guided CPN has demonstrated safety and efficacy due to real-time imaging and anterior access to the celiac plexus from the posterior gastric wall, thereby avoiding complications related to the puncture of spinal nerves, arteries and the diaphragm, and is now practiced widely. Furthermore, two new techniques of EUS-guided neurolysis for abdominal pain management in pancreatic cancer patients have recently been developed. The first technique is EUS-guided celiac ganglia neurolysis (EUS-CGN) in which EUS facilitates CGN by enabling direct injection into the individual celiac ganglion, and the second technique is EUS-guided broad plexus neurolysis (EUS-BPN) which extends over the superior mesenteric artery. This review provides evidence for the efficacy of EUS-CPN. Particular attention is paid to the two new techniques of EUS-guided neurolysis, EUS-CGN and EUS-BPN.

Readmissions following pancreaticoduodenectomy for pancreas cancer: a population-based appraisal

Procedure complexity and volume-outcome relationships have led to increased regionalization of pancreaticoduodenectomy (PD) for pancreas cancer. Knowledge regarding outcomes after PD comes from single-institutional series, which may be limited if a significant number of patients follow up at other hospitals. Thus, readmission data may be underreported. This study utilizes a population-based data set to examine readmission data following PD. California Cancer Registry (1994-2003) was linked to the California's Office of Statewide Health Planning and Development (OSHPD) database; patients with pancreatic adenocarcinoma who had undergone PD, excluding perioperative (30-day) mortality, were identified. All hospital readmissions within 1 year following PD were analyzed with respect to timing, location, and reason for readmission. Our cohort included 2,023 patients who underwent PD for pancreas cancer. Fifty-nine percent were readmitted within 1 year following PD and 47% were readmitted to a secondary hospital. Readmission was associated with worse median survival compared with those not readmitted (10.5 versus 22 months, p<0.0001). Multivariate analysis revealed that increasing T-stage, age, and comorbidities were associated with increased likelihood of readmission. Diagnoses associated with high rates of readmission included progression of disease (24%), surgery-related complications (14%), and infection (13%). Diabetes (1.4%) and pain (1.5%) were associated with low rates of readmission. We found a readmission rate of 59%, which is much higher than previously reported by single institutional series. Concordantly, nearly half of patients readmitted were readmitted to a secondary hospital. Common reasons for readmission included progression of disease, surgical complications, and infection. These findings should assist in both anticipating and facilitating postoperative care as well as managing patient expectations. This study utilizes a novel population-based database to evaluate incidence, timing, location, and reasons for readmission within 1 year following pancreaticoduodenectomy. Fifty-nine percent of patients were readmitted within 1 year after pancreaticoduodenectomy and 47% were readmitted to a secondary hospital.

A cognitive behavioral intervention for symptom management in patients with advanced cancer

PURPOSE/OBJECTIVES

To evaluate the effectiveness of a cognitive behavioral intervention in decreasing symptom severity in patients with advanced cancer undergoing chemotherapy.

DESIGN

Prospective, randomized clinical trial based on cognitive behavioral theory.

SETTING

Six urban cancer centers in the midwestern United States.

SAMPLE

124 patients 21 years of age or older were recruited and randomized to receive conventional care or conventional care and an intervention. Participants were newly diagnosed with stage III, stage IV, or recurrent cancer (solid tumor or non-Hodgkin lymphoma), undergoing chemotherapy, cognitively intact, and able to read and speak English.

METHODS

Data were gathered via telephone interviews at baseline and 10 and 20 weeks after randomization. Nurses with experience in oncology delivered a five-contact, eight-week intervention aimed at teaching patients problem-solving techniques to affect symptom severity.

MAIN RESEARCH VARIABLES

Gender, site of cancer, age, symptom severity and depressive symptoms at baseline, group (i.e., experimental versus control), and total symptom severity.

FINDINGS

Patients in the experimental group and those with lower symptom severity at baseline had significantly lower symptom severity at 10 and 20 weeks; the experimental difference at 20 weeks occurred primarily in those 60 years of age and younger. Depressive symptoms at baseline predicted symptom severity at 20 weeks; however, age, gender, and site of cancer did not affect symptom severity at either time point.

CONCLUSIONS

A cognitive behavioral intervention to teach problem-solving skills can be effective for patient symptom self-management during and following an intervention.

IMPLICATIONS FOR NURSING

Problem-solving strategies should be included in educational programs for patients with advanced cancer, particularly those 60 years of age and younger.