Prolonged Patency Research Articles

Unilateral drainage and chemotherapy prolong the patency of a plastic stent placed above the sphincter of Oddi in patients with malignant hilar biliary obstruction.

To evaluate the results of inside stent therapy for unresectable malignant hilar biliary obstruction and identify factors related to stent patency duration. Of 44 patients who underwent initial inside-stent placement above the sphincter of Oddi from April 2017 to December 2022, 42 with the resolution of jaundice (clinical success rate, 95.5%) were retrospectively analyzed. Univariate and multivariate logistic regression analysis identified factors associated with stent patency duration. Univariate analysis revealed significant differences in the drainage method (406 days for unilateral drainage vs. 305 days for bilateral drainage of the right and left liver lobes, p = 0.022) with or without chemotherapy (406 days with vs. 154 days without, p = 0.038). Multivariate analysis (Cox proportional hazards analysis) revealed similar results, with unilateral drainage (p = 0.031) and chemotherapy (p = 0.048) identified as independent factors associated with prolonged stent patency. Early adverse events were observed in two patients (4.8%; one cholangitis, one pancreatitis). Inside-stent therapy was safely performed in patients with malignant hilar biliary obstruction. Simple unilateral drainage and chemotherapy may prolong stent patency.

Evaluating optimal bilateral biliary stenting in endoscopic reintervention after initial plastic stent dysfunction for unresectable malignant hilar biliary obstruction: Retrospective cross-sectional study.

The placement of plastic stents (PS), including intraductal PS (IS), is useful in patients with unresectable malignant hilar biliary obstruction (UMHBO) because of patency and ease of endoscopic reintervention (ERI). However, the optimal stent replacement method for PS remains unclear. This retrospective study included 322 patients with UMHBO. Among them, 146 received PS placement as initial drainage (across-the-papilla PS [aPS], 54; IS, 92), whereas 75 required ERI. Eight bilateral aPS, 21 bilateral IS, and 17 bilateral self-expandable metallic stent (SEMS) placements met the inclusion criteria. Rates of technical and clinical success, adverse events, recurrent biliary obstruction (RBO), time to RBO (TRBO), overall survival, and secondary ERI were compared. There were no significant intergroup differences in rates of technical or clinical success, adverse events, RBO occurrence, oroverall survival. The median TRBO was significantly shorter in theaPS group (47 days) than IS (91 days; P = 0.0196) and SEMS (143 days; P < 0.01) groups. Median TRBO did not differ significantly between the IS and SEMS groups (P = 0.44). On Cox multivariate analysis, the aPS group had the shortest stent patency (hazard ratio 2.67 [95% confidence interval 1.05-6.76], P = 0.038). For secondary ERI, the median endoscopic procedure time was significantly shorter in the IS (22 min) vs. SEMS (40 min) group (P = 0.034). Bilateral IS and SEMS placement featured prolonged patency after first ERI. Because bilateral IS placement is faster than SEMS placement and IS can be removed during secondary ERI, it may be a good option for first ERI.

Intraductal radiofrequency ablation plus biliary stent versus stent alone for malignant biliary obstruction: a systematic review and meta-analysis.

Background and study aims Recurrent biliary stent occlusion and tumor ingrowth remain a major concern among patients with malignant biliary obstruction (MBO) with significant impact on patient morbidity and survival. Intraductal radiofrequency ablation (RFA) has emerged as a promising treatment that seeks to extend stent patency. This study aimed to evaluate the impact of RFA on overall survival (OS) and stent patency among patients with unresectable MBO. Methods A comprehensive search of electronic databases was performed for randomized controlled trials (RCTs) comparing RFA plus biliary stent (RFA+S) versus biliary stent alone (S-alone). Outcomes assessed included overall survival, stent patency, and adverse events (AEs) with mean difference (MD) calculated from pooled proportions. Subgroup analyses were performed for hilar strictures and cholangiocarcinoma (CCA). Results Six RCTs (n=439 patients) were included and demonstrated improved survival among patients who received RFA+S (MD 85.80 days; 95% confidence interval [CI] 35.02-136.58; I 2 =97%; P <0.0009). The pooled MD for total stent patency was 22.25 days (95% CI 17.38-61.87; I 2 =97%; P =0.27). There was no difference in AEs between RFA+S vs S-alone ( P >0.05). On subgroup analyses, RFA+S was associated with improved stent patency (MD 76.73 days; 95% CI 50.11-103.34; I 2 =67%; P <0.01) and OS (MD 83.14 (95% CI 29.52-136.77; I 2 =97%; P <0.01] for CCA. For hilar strictures, stent patency was improved among patients with RFA+S [MD 83.71 days (95% CI 24.85-142.56; I 2 =84%; P <0.01]. Conclusions RFA+S improved OS in the treatment of MBO when compared with S-alone. Moreover, the RFA therapy prolonged stent patency in hilar strictures and CCA, with similar rates of AEs.

Large Single-center Experience with Long-term Outcomes of EUS-guided Transmural Gallbladder Drainage.

To describe the long-term outcomes of patients after EUS-guided gallbladder drainage (EUS-GBD), including those who underwent standardized stent exchanges for permanent plastic stents. EUS-GBD has become one of the first-line alternatives for gallbladder decompression, with outcomes and safety profiles comparable to that of percutaneous gallbladder drainage. However, the long-term outcomes of EUS-GBD are not well-described. We report our single-center experience of a large cohort who underwent EUS-GBD. Patients who underwent EUS-GBD from August 2014 to December 2022 were included in the study. Patient demographics, comorbidities, and procedure details were recorded. Patients were followed until complete stent removal, end of study period, or death. Short and long-term outcomes include technical and clinical success, stent patency, recurrent cholecystitis, cholecystectomy, and death. During the study period, 128 patients were included. One hundred and one patients had benign indications for EUS-GBD, including cholecystitis and choledocholithiasis. Of those with malignant indications, 23 of 27 had distal malignant biliary obstruction. Technical and clinical successes were 95.3% and 95.1%, respectively. Stents were exchanged for 2 permanent double pigtail plastic stents in 43.0%. The mean stent patency was 421 days (488 d among those still alive) without any recurrent cholecystitis. EUS-GBD demonstrates prolonged stent patency and minimal long-term adverse events, particularly among patients who underwent stent exchanges for permanent plastic stents. EUS-GBD is also promising for patients presenting with choledocholithiasis and biliary colic who are not surgical candidates.

Author commentary on Jung Won Chun et al.

Jung Won Chun et al. Prolonged patency of fully covered self-expandable metal stents with an externally anchored plastic stent in distal malignant biliary obstruction

Maldevelopment of the Immature Pulmonary Vasculature and Prolonged Patency of the Ductus Arteriosus - Association or Cause?

"Maldevelopment of the Immature Pulmonary Vasculature and Prolonged Patency of the Ductus Arteriosus – Association or Cause?." American Journal of Respiratory and Critical Care Medicine, 0(ja), pp. –

Early spontaneous closure of large arterial ducts in two term neonates with Ebstein anomaly after failed attempts of transcatheter closure.

In neonatal Ebstein's anomaly of the tricuspid valve, prolonged ductal patency in patients without anatomic pulmonary valve atresia can be deleterious. Circular shunts may develop in patients with different degrees of pulmonary and tricuspid insufficiency. Closure of the arterial duct may result in haemodynamic improvement in particular scenarios. The transcatheter approach is a valuable closure alternative despite some technical difficulties in large-sized arterial ducts and low birth weight neonates. Herein, we report on two consecutive term newborns with Ebstein's anomaly and large arterial ducts in whom mechanical stimulus of the arterial duct during failed attempts of transcatheter closure led after two days to definitive closure followed by good clinical outcomes.

Midline growth of the sphenoid bone in primates: A histological and microcomputed tomography study

AbstractObjectivesThe aim of the present study is to broaden our knowledge of the ontogeny of cranial base cartilaginous joints in primates.Materials and MethodsA cross‐sectional age sample of 66 specimens from four platyrrhine and three strepsirrhine genera were studied using microcomputed tomography, histology, and immunohistochemistry. Specimens were segmented, reconstructed, and measured using Amira software. Ontogenetic scaling of palatal, presphenoid, and basisphenoid length relative to cranial length was examined using standardized major axis regression. After histological sectioning, selected specimens were examined using immunohistochemistry of antibodies to proliferating cell nuclear antigen.ResultsOur results support the hypothesis that the presphenoid in platyrrhines grows more rapidly compared with strepsirrhines, but this study establishes that most or all of this growth discrepancy occurs prenatally, and mostly at the presphenoseptal synchondrosis (PSept). All species have prolonged patency (here meaning absence of any bony bridging across the synchondrosis) of the intrasphenoidal and spheno‐occipital synchondroses (ISS). However, immunohistochemical results suggest growth is only rapid throughout infancy, and mitotic activity is slowing during juvenile ages. The same is indicated for the PSept.DiscussionThese results demonstrate that platyrrhines and strepsirrhines do not follow the pattern of early fusion of ISS seen in humans. In addition, these primates have a more prolonged patency and growth at PSept compared with humans. Finally, results reveal that in bushbabies and tamarins, as in humans, synchondroses remain cartilaginous for a prolonged period after chondrocyte proliferation has slowed or ceased. In light of these results, it is time to reassess related processes, such as differences in timing of brain expansion.

Endoscopic radial incision versus endoscopic balloon dilation as initial treatments of benign esophageal anastomotic stricture.

We aim to evaluate the efficacy and safety of endoscopic radial incision (ERI) versus endoscopic balloon dilation (EBD) treatment of naïve, recurrent, and refractory benign esophageal anastomotic strictures. One hundred and one ERI, 145 EBD, and 42 ERI combined with EBD sessions were performed in 136 consecutive patients with benign esophageal anastomotic stricture after esophagectomy at Zhongshan Hospital from January 2016 to August 2021. Baseline characteristics, operational procedures, and clinical outcomes data were retrospectively evaluated. Parameters and recurrence-free survival (RFS) were compared between ERI and EBD in patients with naïve or recurrent or refractory strictures. Risk factors for re-stricture after ERI were identified using univariate and multivariate analyses. Twenty-nine ERI versus 68 EBD sessions were performed for naïve stricture, 26 ERI versus 60 EBD for recurrent strictures, and 46 ERI versus 17 EBD for refractory stricture. With comparable baseline characteristics, RFS was greater in the ERI than the EBD group for naïve strictures (P=0.0449). The ERI group had a lower 12-month re-stricture rate than the EBD group (37.9% vs 61.8%, P=0.0309) and a more prolonged patency time (181.5±263.1 vs 74.5±82.0, P=0.0233). Between the two interventions, recurrent and refractory strictures had similar RFS (P=0.0598; P=0.7668). Multivariate analysis revealed initial ERI treatment was an independent predictive factor for lower re-stricture risk after ERI intervention (odds ratio=0.047, P=0.001). Few adverse events were observed after ERI or EBD (3.0% vs 2.1%, P=0.6918). ERI is associated with lower re-stricture rates with better patency and RFS compared with EBD for naive strictures.

Management of Y-Site Incompatibility of Intravenous Medication: A Systematic Review

Patients in intensive care units have a critical problem with Intravenous (IC) drug administration. The effort to decrease incompatibility or manage the incompatibility risks is paramount significant to reduce morbidity and mortality. This review collates all published studies about kinds of approaches to prevent or solve y-site incompatibility, evaluate the effectiveness of those approaches, and provide the recommendation. A scoping review was conducted in PUBMED in a time frame 1 Januari 2010- 28 February 2021. All type studies of randomised controlled trials, observational studies, before and after studies, also review articled were considered to include. We identified 944 studies; of these, 78 met the inclusion criteria, but 44 were excluded. A total 34 articles were included in the analyses. Six articles reported protocol, two-dimensional chart, database, or pH colour code to provide information of incompatibilities. Two-dimensional chart and pH code were comparable with a gold standard. Specific protocol markedly reduced the incompatibility event. Normal saline (NS) flushing effectively prolonged patency and reduced the incompatibility rate. NS was preferred over heparin associated with thrombocytopenia. In-line filtration has been proved to reduce particulate matter, as well as the precipitation, resulted from incompatibility. The filter also reduced inflammation, infection, and complication appreciably. Four studies used more than three lumen catheters which successfully decrease the number of precipitation and incompatibility events. Therefore, separating incompatible drugs using multi-lumens according to the chart should be preferred. However, when co-administration is inevitable, flushing or filter is needed.

Jailbreaking a metal biliary stent through a duodenal stent.

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Hemodialysis Arteriovenous Fistula Dysfunction: Retrospective Comparison of Post-thrombotic Percutaneous Endovascular Interventions with Pre-emptive Angioplasty

We aimed to compare the clinical outcomes of pre-emptive angioplasty versus post-thrombotic percutaneous endovascular restoration of dysfunctional arteriovenous fistula (AVF). This retrospective study reviewed the data from 80 patients who underwent 114 endovascular interventions for a malfunctioning AVF from July 2016 to August 2019. Stenotic AVFs were treated with pre-emptive angioplasty. Thrombosed AVFs were treated with percutaneous pharmacomechanical fibrinolysis with urokinase used only during the operation or continuously infused. The differences in patency rates were evaluated using the Kaplan-Meier method. In addition, univariate and multivariate regression Cox models were used to determine influential factors on the postintervention primary patency. Post-thrombotic interventions and pre-emptive angioplasty yielded statistically similar rates in clinical success (100 vs. 100%), anatomic success (94 vs. 89%; P=0.52), complication (4 vs. 11%; P=0.29), as well as postintervention primary, assisted primary and secondary patency (P=0.80; 0.57; 0.57). The use of pre-emptive angioplasty was associated with reduced total cost (¥25,108 vs. ¥30,833, P<0.001). The patients who used urokinase only during the operation prolonged both the primary and assisted primary patency (P=0.02; 0.002), while those with continuous infusion of urokinase had worst patency rates and high costs (¥39,275 vs. ¥25,108 vs. ¥27,140, P<0.001). Compared with the other locations, dysfunction in the anastomotic or juxta-anastomotic segment (HR=0.41, P=0.001) was associated with prolonged postintervention primary patency. No clinical outcome differences were found between the post-thrombotic percutaneous endovascular interventions and pre-emptive angioplasty. However, pre-emptive angioplasty decreased access expenditure.

Radioactive stent insertion for inoperable hilar cholangiocarcinoma: a prospective randomized controlled trial.

Hilar cholangiocarcinoma (HC) is the leading cause of hilar biliary obstruction. Radioactive stent insertion has been utilized extensively for inoperable HC patients. To assess the relative clinical outcomes of inoperable HC patients who underwent either normal or radioactive stent insertion. This single-center, prospective, randomized, open-label study enrolled 90 inoperable HC patients from April 2021 to March 2022 and randomly assigned them to normal or radioactive stent groups (n = 45/group), with clinical data then being compared between these groups. Technical success rates in the normal and radioactive stent insertion groups were 93.3% and 97.9%, respectively (p = 1.000), and clinical success rates were similarly consistent in both groups (95.3% vs. 97.7%, p = 0.983). Individuals in the radioactive stent group exhibited significantly longer median stent patency as compared to the normal stent group (195 days vs. 115 days, p < 0.001), and median overall survival (OS) was also significantly increased in the normal stent group (242 days vs. 125 days, p = 0.002). In the normal stent insertion group, 6 (14.3%) and 5 (11.9%) patients experienced early and late postoperative complications, respectively. Additionally, early and late postoperative complications impacted 7 (16.3%) and 8 (18.6%) patients in the radioactive stent insertion group, respectively. Complication rates were comparable in these 2 patient groups. Radioactive stent insertion represents a safe and effective strategy for patients with inoperable HC, potentially contributing to prolonged stent patency and OS relative to normal stent insertion.

Studying in vivo and in vitro effects of a novel polyvinyl benzyl chloride-D-glucaro-1, 4-lactonate polymer-coated bile duct stent for anti-biliary mud deposition.

We aim to coat a novel polyvinyl benzyl chloride-D-glucaro-1, 4-lactonate polymer-coated bile duct stent for anti-biliary mud deposition and investigate its in vivo and in vitro impacts. Biliary mud deposition is a leading cause of plastic biliary stent obstruction after its placement. Orally administrated D-glucaro-1, 4-lactonate is a specific competitive inhibitor of β-glucuronidase that causes biliary mud deposition. In this study, the stents coated with polyvinyl benzyl chloride-D-glucaro-1,4-lactonate polymer (PVBC-DGL) were placed in an ex vivo bile duct model perfused with porcine bile and observed every week until completely blocked. Post establishing the model of bile duct stenosis in piglets, stents are observed through endoscopy, hematology, patency time, and pathological changes within 6 months. The 70% PVBC-DGL stents achieved the highest percentage of the inhibitory effect when the drugs were completely released in vitro. Results were obtained from 14 pigs (5: no coating (original), 4: 0% coating, and 5: 70% coating). The overall patency time of the stents was prolonged in all groups; however, the group with 70% coated stents showed a significantly prolonged patency time as compared to no coating (original) and the 0% coating groups in pigs (23.4 ± 1.8 vs 11.2 ± 2.1 w (p = 0.05); 23.4 ± 1.8 vs 10.5 ± 2.5 w (p = 0.05), respectively). The stents with 70% PVBC-DGL better prevent and control the deposition of bile mud and prolong the patency time of stent placement in the subject animals and may be proposed for further clinical trials in patients.

Localized Photothermal Ablation Therapy of Obstructive Rectal Cancer Using a Nanofunctionalized Stent in a Mouse Model.

The self-expanding metal stent (SEMS) is a versatile, palliative treatment method for unresectable, malignant, non-vascular strictures. Colorectal cancer (CRC) is one of the candidates for the application of the SEMS, in combination with the photothermal ablation (PTA) technique that enhances its therapeutic efficacy. The objective of this study was to investigate the efficacy of stent-mediated PTA therapy in an endoscopy-guided, orthotopic rectal cancer model. A total of 30 of 40 mice with the tumor size of grade 4 were included and were divided into three groups of 10 mice each. Group A underwent a gold nanoparticle (AuNP)-coated SEMS but no near-infrared (NIR) irradiation, group B received an uncoated control SEMS with NIR irradiation, and group C received a AuNP-coated SEMS and NIR irradiation together. Colonoscopy and in vivo imaging, immunohistochemical analysis, and quantitative reverse-transcription polymerase chain reaction of major tumor markers were performed. Stent placement and PTA were technically successful using colonoscopy. The tumor grade reduction after PTA is significant in group C, compared with groups A or B (p < 0.001). Molecular analysis validated this observation with a significantly reduced Mapk1 proliferation marker or increased Jnk expression. Histological analysis confirmed the localized PTA therapy using AuNP-coated SEMS profoundly ablated tumor outgrowth through the stent. Our results indicate that this novel strategy of localized PTA therapy could be a promising option for palliative treatment of CRC and to support prolonged stent patency with a decreased tumor volume.

10 High spontaneous ductal closure even at the extreme of prematurity

Abstract Primary Subject area Neonatal-Perinatal Medicine Background Extremely preterm newborns are at risk of prolonged patency of the ductus arteriosus (PDA). Current literature has failed to indicate improvement in outcomes after exposure to strategies promoting ductal closure. As such, our center abandoned these practices in 2013. Objectives Describe the spontaneous PDA closure in premature infants, including those infants born at the extreme of gestational age (&amp;lt; 26 weeks). Design/Methods Retrospective study of newborns &amp;lt; 29 weeks, admitted within 24 hours after birth between 2015 and 2019 and without genetic or congenital anomalies. Newborns who were last known to be alive, with an available echocardiography, and who were not exposed to any intervention to accelerate PDA closure were included. Images were reviewed by experts blinded to the outcomes. Results 296 infants were analyzed. 37 (12%) did not survive their hospitalization, and 16 were exposed to interventions to accelerate ductal closure at some point during their lifetime (4 ligations, 4 catheter-closure, 5 ibuprofen and 3 acetaminophen). Out of the 243 remaining newborns, 214 had at least one echocardiography to ascertain ductal patency or closure (100% of those &amp;lt;26 weeks). The average gestational age was 26.3±1.5 weeks, with 84 (39%) being &amp;lt;26 weeks. PDA closed spontaneously in 194 (91%), with 60 having closure ascertainment after discharge (average age at closure ascertainment of 36.4 [IQR: 34.4 – 40.1] weeks). Of the 84 &amp;lt;26 weeks, 76 (90%) had confirmation of ductal closure. The 20 infants with an open PDA at the last evaluation were followed in an outpatient setting and considered small/restrictive. In our cohort, 92/243 (38%) were exposed to post-natal steroids. In the &amp;lt;26 weeks group, 74% were exposed to steroids, at a cumulative dose of 1.64 [0.89 – 2.44] mg/kg. BPD was found in 57% of the overall cohort and in 79% of &amp;lt;26 weeks. Conclusion The majority of newborns &amp;lt; 29 weeks, and even those at the extreme of gestational age (&amp;lt; 26 weeks) spontaneously closed their PDA before term-corrected age. While BPD rate was similar to previous cohorts, post-natal steroids use was high.

9 The Burden of Bronchopulmonary Dysplasia and Pulmonary Vascular Disease in Premature Infants

Abstract Primary Subject area Neonatal-Perinatal Medicine Background Extremely premature infants are at a high risk of bronchopulmonary dysplasia (BPD) and BPD-associated pulmonary hypertension (PH). Prolonged patency of the ductus arteriosus (PDA) may worsen PH; however, due to the lack of evidence supporting improvement in outcomes after strategies to promote ductal closure, our center has adopted a strict non-intervention policy since 2013. Objectives Assess PH prevalence and severity, as well as the impact of BPD on echocardiographic parameters of cardiac performance. Design/Methods Retrospective cohort of infants &amp;lt;29 weeks gestational age at birth, admitted between 2015 and 2019, and without genetic/congenital anomalies. Measurements from the echocardiography acquired closest to 36 weeks were done by masked experts. Severe BPD was defined as positive pressure support at 36 weeks. PH was defined as an estimated systolic pulmonary pressure (SPAP) ≥40 mmHg or an abnormal septal curvature by eccentricity index (EI) (&amp;gt;1.3). Results Out of 387 infants, 222 were included, of which 27 (12%) were categorized as severe BPD and 78 (35%) had PH. Severe BPD was associated with lower birth weight (704±214 vs 842±229g, p&amp;lt;0.01), longer hospitalization (median 138 [IQR 108-167] vs 103 [IQR 86-125] days, p&amp;lt;0.01) and longer mechanical ventilation duration (median 82 [IQR 33-107] vs 17 [IQR 2-32] days, p&amp;lt;0.01), with no difference in gestational age at birth. Severe BPD was associated with PH (70% vs 43%, p&amp;lt;0.01). The combined outcome of death (after the 36 weeks echocardiography) or severe BPD was associated with PH (68% vs 30%, p&amp;lt;0.01), smaller left ventricle length in diastole (2.8±0.5 vs 3.0±0.5 cm, p=0.03), decrease in the tricuspid annular plane systolic excursion (0.7±0.2 vs 0.9±0.2 cm, p&amp;lt;0.01), abnormal EI (1.31±0.25 vs 1.17±0.18, p&amp;lt;0.01) and smaller right ventricle fraction area change (41.3±5.8 vs 47.8±7.6%, p&amp;lt;0.01), without a significant increase on SPAP (35±21 vs 35±14, p=0.15). Other echocardiographic markers were similar. Conclusion In the context of a PDA non-intervention policy, a third of our population was affected by PH at 36 weeks. Furthermore, those with severe BPD or death had signs of RV dysfunction (despite similar SPAP estimate), indicating that the effect of BPD on pulmonary vascular remodelling and cardiac function may be underestimated.

Pulmonary Hypertension with Prolonged Patency of the Ductus Arteriosus in Preterm Infants.

There continues to be a reluctance to close the patent ductus arteriosus (PDA) in premature infants. The debate on whether the short-term outcomes translate to a difference in long-term benefits remains. This article intends to review the pulmonary vasculature changes that can occur with a chronic hemodynamically significant PDA in a preterm infant. It also explains the rationale and decision-making involved in a diagnostic cardiac catheterization and transcatheter PDA closure in these preterm infants.

Folfirinox chemotherapy prolongs stent patency in patients with malignant biliary obstruction due to unresectable pancreatic cancer

Background: Stent insertion for biliary decompression to relieve jaundice and subsequent biliary infection is necessary for patients with biliary obstruction caused by pancreatic cancer, and it is important to keep the stent patent as long as possible. However, few studies have compared stent patency in terms of chemotherapy in patients with pancreatic cancer. This study aimed to evaluate the differences in stent patency in terms of recently evolving chemotherapy.Methods: Between January 2015 and May 2017, 161 patients with pancreatic cancer who had undergone biliary stent insertion with a metal stent were retrospectively analyzed. The relationship between chemotherapy and stent patency was assessed. Additionally, overall survival according to the treatment, risk factors for stent patency, and long-term adverse events were evaluated.Results: Median stent patency was 42 days for patients with the best supportive care and 217 days for patients with chemotherapy (conventional gemcitabine-based chemotherapy and folfirinox) (P < 0.001). Furthermore, the folfirinox group showed the longest median stent patency and overall survival, with 283 days and 466 days, respectively (P < 0.001) despite higher adverse events rate. Patients who underwent folfirinox chemotherapy after stent insertion had better stent patency in multivariate analysis (HR = 0.26; 95% CI: 0.12–0.60; P = 0.001).Conclusions: Compared with patients who received best supportive care only, patients who underwent chemotherapy after stent insertion had better stent patency. More prolonged stent patency can be expected for patients with folfirinox than conventional gemcitabine-based chemotherapy.

The chondrocranial key: Development of the sphenoid bone in primates

It has been hypothesized that the human sphenoid bone is uniquely truncated, which in turn contributes to a reduction of forward midfacial growth. If so, the perinatal fusion of the intrasphenoidal synchondrosis (ISS) in humans may contribute to midfacial reduction. However, there is a lack of detailed knowledge on sphenoid development of non‐human primates. In this study, orientation and direction of growth of basicranial interface with the midface of late prenatal and early postnatal sphenoid development was examined in ontogenetic samples of primates including three species of monkeys (n = 25) and four species of lemurs and bushbabies (strepsirrhines; n= 28). Micro‐computed tomographic (CT) and histological methods were used to track cross‐sectional age changes in the sphenoid bone. In monkeys (Saguinus spp.), histological findings indicated the number of proliferating chondrocytes is reduced across age leading to a reduction in absolute anteroposterior length of the proliferating zone. Preliminary data from micro‐CT reconstructions suggest that absolute length of the ISS decreases more rapidly in monkeys than in strepsirrhines. Measurements of presphenoid (PS) and basisphenoid (BS) length indicate that in strepsirrhines, these bones grow similarly to one another as cranial length increases. In contrast, in monkeys, the PS increases at a faster pace (i.e. higher linear regression line slopes) than the BS. However, unlike humans, the monkeys studied have prolonged postnatal patency of the ISS. Thus, the reduced midfacial projection in humans and these monkeys cannot be explained by the timing of ISS fusion alone. Dichotomous growth patterns of the cranial base and midface among primates suggest different patterns of regional integration of the cranium. In particular, our results suggest that in monkeys, integration of the midface is stronger with the anterior compared to the posterior portion of the sphenoid bone. In strepsirrhines by comparison, growth of the midface progressively deviates from that of the sphenoid bone over time.Support or Funding InformationNSF; grant numbers BCS‐1830894, BCS‐1830919, BCS‐0959438