Association between time to stent dysfunction and the anti-tumour effect of systemic chemotherapy following stent placement in patients with pancreaticobiliary cancers and malignant gastric outlet obstruction: a retrospective cohort study

Analysis of prognostic factors in patients with self-expandable metallic stents for treatment of malignant gastric outlet obstruction

BACKGROUND AND AIM

Self-expandable metallic stents (SEMSs) are widely accepted as a less-invasive treatment for malignant gastric outlet obstruction (GOO). However, the factors related to prognosis and stent dysfunction after SEMS placement are not well known, and we aimed to investigate them.

METHODS

This was a single-center retrospective cohort study of 212 malignant strictures in 207 patients. Factors related to prolonged overall survival (OS) and time to recurrent GOO (TRGOO) after SEMS placement were evaluated.

RESULTS

Improvement of oral intake was confirmed in 179 patients (86%). The median OS was 65 days. A Cox proportional hazards model revealed that lower cancer stage, lower performance status score at the time of SEMS placement, and administration of chemotherapy after SEMS placement were significant predictive factors for prolonged OS. The median OS was 182 days in the group of SEMS followed by chemotherapy (group A) and 43 days in the group of SEMS alone (group B) (p< .0001). Chemotherapy after SEMS implantation contributed to the prolongation of survival in gastric cancer (hazard ratio (HR), 0.12) and pancreatic cancer (HR, 0.41). Furthermore, the cumulative incidence rates of stent dysfunction on day 120 after SEMS placement were 30% in group A and 61% in group B (p=.03). Notably, the preventive effect of chemotherapy on stent dysfunction was significant in pancreatic cancer.

CONCLUSIONS

SEMS is a treatment with high technical and clinical success rate for malignant GOO. Furthermore, subsequent chemotherapy prolongs OS especially in gastric cancer, and TRGOO in pancreatic cancer.

Outcomes after partially covered self-expandable metal stent placement for recurrent duodenal obstruction

BACKGROUND

Outcomes of partially covered self-expandable metal stents (SEMS) as an additional stent after recurrent duodenal obstruction (RDO) have not been elucidated. In this study, we compared outcomes of partially covered and uncovered SEMS placement after RDO in patients with malignant duodenal obstruction and explored factors affecting re-recurrent obstruction and overall survival in this population.

METHODS

We conducted a retrospective study of patients undergoing SEMS placement for RDO at a cancer institute in Japan from July 2014 to June 2021. Clinical variables and outcomes of patients undergoing partially covered and uncovered SEMS placement were compared.

RESULTS

Sixty-one patients underwent SEMS placement after RDO, for which the COMVI stent was used in 38 cases and uncovered stents were used in 23 cases. Stent ingrowth was the most common cause of RDO (51.4%). Stent migration only occurred after partially covered stent placement (20% vs. 0%, p = 0.018). Choice of SEMS had no impact on time to re-RDO (median 2.8 vs. 4.1 months, p = 0.776) or overall survival (median 2.6 vs. 2.4 months, p = 0.703). Median overall survival was longer in patients receiving chemotherapy after second stenting (4.6 vs. 1.8 months, p < 0.001) and shorter in those with early RDO, regardless of the SEMS used. Use of the partially covered stent had no impact on survival or time to RDO.

CONCLUSIONS

While outcomes after partially covered SEMS placement for RDO were not significantly different from uncovered SEMS, migration remains a concern when they are used as a second stent. Chemotherapy after second stenting was associated with longer overall survival but not with longer time to re-RDO.

Toxic Metals and Metalloids in Hassawi Brown Rice: Fate during Cooking and Associated Health Risks

Rice has been a dietary staple for centuries, providing vital nutrients to the human body. Brown rice is well known for its nutrient-dense food profile. However, owing to multiple causes (anthropogenic and non-anthropogenic), it can also be a potential source of toxic heavy metals in the diet. Brown Hassawi rice samples were collected from the Al-Ahsa region and analyzed for its content of toxic metals. The results reveal that all the tested metals varied significantly in the brown rice samples, while As and Pb in all three samples exceeded their respective maximum allowable limits (MALs), followed by Cd, which nearly approached the MAL in two samples out of three. Brown rice samples were cooked in rice:water systems, viz., low rice:water ratios (1:2.5, 1:3.5) and high rice:water ratios (1:5, 1:6), along with soaking as a pre-treatment. Soaking was unproductive in removing the heavy metals from the rice, whereas cooking dissipated all metals from the rice, except for Cd, which was statistically non-significant. The high-water cooking of the rice was more effective in the dissipation of metals from the rice as compared to low-water cooking conditions. Through the consumption of rice, the estimated daily intake (EDI) of heavy metals is 162 g per person per day for As, which is above the provisional maximum tolerable daily intake (PMTDI) regardless of cooking circumstances. The hazard risk index (HRI) also highlighted the fact that As can be a potential health hazard to rice consumers in the Al-Ahsa region of Saudi Arabia. These results indicate the potential health risks caused by the consumption of this rice by humans. Regular monitoring is recommended to manage and control elevated concentrations and related health hazards as a result of the use of Hassawi rice contaminated by the accumulation of metals and metalloids.

How to successfully administer palliative treatment with a stent for malignant gastric outlet obstruction?

Although endoscopic stenting (ES) has been widely used as a less-invasive palliation method for malignant gastric outlet obstruction (GOO), recent reports have highlighted issues related to the procedure. For successful treatment, various aspects must be assessed before considering the practices. First, it is necessary to eliminate cases with contraindications such as coexistence of distal small-bowel obstruction or perforation. Other factors potentially related to clinical failure (i.e., peritoneal carcinomatosis) may require consideration but remain controversial. ES has better short-term outcomes than surgical gastrojejunostomy (GJ). GJ has recently been considered preferable in cases with longer life expectancy because of superior sustainability. Various types of stents are now commercially available, but their ideal structure and mechanical properties have not yet been clarified. Covered metal stent may reduce stent obstruction but is prone to increase stent migration, and its significance remains uncertain. Subsequent chemotherapy after stenting should be considered, as it is expected to prolong patient survival without increasing the risk of adverse events. Furthermore, it may be helpful in preventing tumor ingrowth. In cases with GOO combined with biliary obstruction, biliary intervention is often difficult. Recently, endoscopic ultrasound-guided biliary drainage (EUS-BD) has been widely used as an alternative procedure for endoscopic transpapillary biliary drainage (ETBD). Despite the lack of consensus as to whether ETBD or EUS-BD is preferred, EUS-BD is useful as a salvage technique for cases where ETBD is difficult. To perform stent placement successfully, it is important to pay attention to the above points; however, many remaining issues need to be clarified in the future.

Endoscopic Double Stenting for the Management of Combined Malignant Biliary and Duodenal Obstruction

Periampullary cancers are often diagnosed at advanced stages and can cause both biliary and duodenal obstruction. As these two obstructions reduce patients’ performance status and quality of life, appropriate management of the disease is important. Combined malignant biliary and duodenal obstruction is classified according to the location and timing of the duodenal obstruction, which also affect treatment options. Traditionally, surgical bypass (gastrojejunostomy and hepaticojejunostomy) has been performed for the treatment of unresectable periampullary cancer. However, it has recently been substituted by less invasive endoscopic procedures due to its high morbidity and mortality. Thus, endoscopic double stenting (transpapillary stenting and enteral stenting) has become the current standard of care. Limitations of transpapillary stenting include its technical difficulty and the risk of duodenal-biliary reflux. Recently, endoscopic ultrasound-guided procedures have emerged as a novel platform and have been increasingly utilized in the management of biliary and duodenal obstruction. As the prognosis of periampullary cancer has improved due to recent advances in chemotherapy, treatment strategies for biliary and duodenal obstruction are becoming more important. In this article, we review the treatment strategies for combined malignant biliary and duodenal obstruction based on the latest evidence.