Duodenal gastrointestinal stromal tumors: A retrospective study based on a 13 years experience of a single center in China.

AIM: Duodenal gastrointestinal stromal tumors (GISTs) constitute a small rare subset. This study aims to analyze the prognostic differences between duodenal and jejunoileal GISTs and evaluate the clinical treatment and prognostic characteristics of patients with duodenal GISTs. METHODS: Data of patients with primary duodenal or jejunoileal GISTs were collected. Patients were matched through propensity score matching (PSM). Perioperative and long-term outcomes of patients with duodenal GISTs were compared based on surgical approach. RESULTS: Altogether, 101 duodenal and 219 jejunoileal GISTs were identified. In patients with duodenal GISTs, 79 (78%) underwent local resection (LR) and 22 (22%) underwent pancreaticoduodenectomy (PD). Patients undergoing PD had a longer postoperation stay (18.5 vs 13 days, P = 0.001) and more complications (Clavien-Dindo I-II complications for PD vs LR, 31.8 vs 15.2%; Clavien-Dindo III-V complications for PD vs LR, 22.7 vs. 2.5%; P < 0.001). There was no difference in recurrence-free survival (RFS) (P = 0.8) or overall survival (OS) (P = 0.9) when comparing patients who underwent LR versus PD. Multivariable analysis showed that tumor size >5 cm was the only independent predictor of shorter RFS (P = 0.004) and OS (P = 0.012). After matching, there was no significant difference in RFS and OS between patients with duodenal versus jejunoileal GISTs (both P > 0.05). CONCLUSION: The prognosis of duodenal and jejunoileal GISTs are similar. Recurrence and OS of duodenal GISTs primarily depend on tumor size. For duodenal GISTs, LR is associated with comparable long-term survival when compared to PD, but with superior short-term outcomes.

Elevated preoperative platelet-to-lymphocyte ratio predicts poor prognosis of patients with primary gastrointestinal stromal tumor.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are considered to reflect the systemic inflammatory response and clinical prognosis. However, the independent prognostic values of the NLR and PLR for patients with gastrointestinal stromal tumor (GIST) remain debatable. This study aims to evaluate the prognostic value of preoperative NLR and PLR in GIST patients. METHODS: We retrospectively reviewed all GIST patients diagnosed and surgically treated at Union Hospital between 2005 and 2018. The preoperative NLR and PLR were calculated to evaluate recurrence-free survival (RFS) and overall survival (OS) by Kaplan-Meier analysis. Univariate and multivariate Cox regression analyses were performed to estimate the independent prognostic values. RESULTS: The median follow-up time was 49 months (interquartile range, 22-74 months). The preoperative PLR was significantly increased in the GIST patients with intermediate and high tumor risks. Increases in the NLR (≥2.34) and PLR (≥185.04) were associated with shorter RFS and OS (P < 0.01). Moreover, the multivariate analysis revealed that elevated PLR was an independent factor for shorter RFS (hazard ratio [HR]: 3.041; 95% confidence interval [CI]: 2.001-4.622; P < 0.001) and OS (HR: 1.899; 95% CI: 1.136-3.173; P = 0.014). CONCLUSIONS: The preoperative PLR is a potential biomarker of GIST and is related to the clinical outcome. An elevated preoperative PLR predicts poor prognosis of patients with primary GIST after complete surgical resection.

Development and evaluation of a genetic algorithm-based ocean color inversion model for simultaneously retrieving optical properties and bottom types in coral reef regions.

This work presents a novel approach that integrates a shallow water semi-analytical (SSA) model and a genetic algorithm (GA) to retrieve water column inherent optical properties (IOPs) and identify bottom types simultaneously from measurement of subsurface remote sensing reflectance. This GA-SSA approach is designed based on the assumption that each pixel is homogeneous with regard to the bottom type when viewed at small (centimeter) scales, and it is validated against a synthetic data set (N=11,250) that consists of five types of bottom, three levels of bottom depth, 15 concentrations of chlorophyll-a (Chl-a), and a wide range of modeled IOP variations in clear and optically complex waters representing the coral reef environment. The results indicate that the GA-SSA approach is accurate and robust in the retrieval of IOPs and its success rate in identifying the real bottom type is limited by the level of Chl-a and bottom depth. When a pixel is homogeneous at a small scale, the maximum allowable concentrations for GA-SSA to perfectly identify all the five bottom types are 0.7 mg/m3 at 5 m bottom depth, 0.2 mg/m3 at 10 m, and 0.07 mg/m3 at 15 m. A promising 80% recognition rate of the benthic community is possible with GA-SSA when an underwater hyperspectral imager is deployed to examine the health status of coral reefs in a clean (Chl-a<1 mg/m3) and shallow (bottom depth<10 m) environment. Further study that collects field data for direct validation is required to ensure that the GA-SSA approach is also applicable in real coral reef regions.

Subdural intrathecal catheter placement: experience with two cases.

BACKGROUND: Subdural migration of epidural catheters is well known and documented. Subdural placement of intrathecal catheters has not been recognized. Two cases of sudural placement of intrathecal catheters are presented. OBJECTIVE: The possibility of subdural migration of epidural catheters and its manifestations has been well documented. The following 2 cases demonstrate that intrathecal catheters can enter the subdural space upon placement. CASE REPORTS: The first case is a 52-year-old male with multiple sclerosis receiving a pump for intrathecal baclofen. It worked well for 10 years, but after 2 months of inadequate relief despite a 2-fold increase in baclofen, the catheter was imaged. The catheter pierced the arachnoid in the lower thoracic spine and tunneled subdural. It then pierced the arachnoid again, re-entering the cerebrospinal fluid (CSF) in the cephalad portion of the thoracic spine. Over time, the tip became covered with tissue, preventing direct CSF communication and causing subdural drug sequestration. The second case is a 54-year-old male with chronic bilateral lower extremity pain having a pump placed for pain control. Because of inadequate relief after implantation, the catheter was imaged. It pierced the arachnoid at L4-L5 but became subdural at T12-L1. At the time of surgical revision, the catheter was pulled back to L2. Repeat imaging showed it to be entirely subarachnoid, and analgesia was restored. CONCLUSIONS: These cases differ from others in the literature because the catheter was apparently subdural at the time of initial implantation. As these 2 cases demonstrate, this placement may manifest immediately, but it may remain undetected for a prolonged period. Initial subdural placement should be considered along with catheter migration into the subdural space in the differential of a malfunctioning pump.