Drag Forces after Thoracic Endovascular Aortic Repair. General Review of the Literature.

BACKGROUND: Despite the great evolution of endograft devices for thoracic endovascular aortic repair (TEVAR), threatening related complication such as graft migration and endoleaks still occur during follow up. The Drag Forces (DF), that is the displacement forces that play a role in graft migration and endoleaks caused by the blood flow against the thoracic graft, can be studied by means of Computational Fluid Dynamics (CFD). METHOD: A general review of papers found in current literature was performed. CFD studies available on the topic of thoracic aortic diseases and DF were analyzed. All anatomic, hemodynamics or graft related factors which could have an impact on DF were reported. RESULTS: Different factors deeply influence DF magnitude in the different site of the Ishimaru's zones classification: angulation, tortuosity and length of the landing zone, graft diameter, length and deployment position, blood pressure, pulse waveform, blood viscosity and patient heart rate have been related to the magnitude of DF. Moreover, also the three-dimensional orientation of DF is emerging as a fundamental issue from CFD studies. DF can be divided in sideways and upward components. The former, even of higher magnitude in zone 0, maintain always an orthogonal orientation and does not change in any type of aortic arch; the latter result strictly related to the anatomic complexity of the aortic arch with values up to four times higher in zone 3. CONCLUSION: Different DF magnitude and orientation could explain how TEVAR have higher rate of migration and endoleaks when we face with more complex aortic anatomies. All these aspects should be foreseen during the planning of TEVAR procedure. In this field, collaboration between physicians and engineers is crucial, as both parts have a primary role in understanding and describing hidden aspects involved in TEVAR procedures.

Another Use for EUS: Removal of a Transesophageal-Migrated Mediastinal Foreign Body.

Removal of foreign bodies from the upper gastrointestinal tract, though a common occurrence, can be technically challenging and risky. We report the case of a young man that, after eating a pizza cooked in a wood-burning oven, reported a sense of foreign body. Though the first evaluation by fiberoptic laryngoscopy found no foreign body, after a few weeks, the patient was readmitted from the ER for worsening symptoms and fever. A CT scan showed a metallic mediastinal foreign body inside a large fluid collection. After multidisciplinary evaluation, an endoscopic removal was attempted by accessing the mediastinal collection through EUS-guided positioning of a Hot Axios™ stent. The cavity was drained by naso-esophageal suction. The foreign body was a fragment of the brush used to clean the oven. The patient is now doing well after 7 months.

Successful repositioning of apically tethered transcatheter mitral valve replacement in the off-bypass, beating heart.

A 73-year-old man with severe, symptomatic secondary mitral regurgitation (MR) underwent successful transcatheter mitral valve replacement using the Tendyne™ mitral valve system. The device was deployed from the left ventricular (LV) apex and secured in position by a tether attached to an epicardial pad. Three days postoperatively, the patient developed hemolytic anemia and a paravalvular leak (PVL) associated with indentation of the LV apex. Adjustment of the tether tension and placement of an epicardial disc under the pad resulted in reduction in the PVL, and resolution of the hemolytic anemia.

Migration of hem-o-lock clips and stitches into the duodenum after laparoscopic hepatectomy and cholecystectomy: A case report.

RATIONALE: Migration of endoclips and stitches into the duodenum after laparoscopic hepatectomy is incredibly rare with a poorly understood mechanism. PATIENT CONCERNS: A 56-year-old woman who underwent laparoscopic left hepatectomy and cholecystectomy in August 2016 was admitted to our hospital with nausea and vomiting in December 2017. DIAGNOSES: Abdominal computed tomography (CT) scan showed high density shades in duodenal ampulla. Esophagogastroduodenoscopy showed deformation of the duodenal ampulla into two lumens; hem-o-lock clips and stitches were detected in the upper lumen. Contrast enhanced CT scan revealed gastric cancer with liver metastasis (GCLM). INTERVENTIONS: The hem-o-lock clips and stitches were present in the wall of the duodenum; therefore, no attempt was made to remove them. High quality liquid diet, partial parenteral nutrition, and chemotherapy were administered to the patient. OUTCOMES: In September 2018, the patient died of hepatic failure caused by GCLM. LESSONS: This rare complication of the migration of endoclips and stitches into the duodenum after laparoscopic hepatectomy can cause epigastric pain and duodenal obstruction. The complication could be potentially avoided using absorbable endoclips and stitches or by performing of ultrasonic dissection by a skilled operator.

Impact of the Bird-Beak Configuration on Postoperative Outcome After Thoracic Endovascular Aortic Repair: A Meta-analysis.

Purpose: To investigate the association between the bird-beak configuration (BBC), a wedge-shaped gap between the undersurface of a thoracic endograft and the lesser curvature of the arch after thoracic endovascular aortic repair (TEVAR), and postoperative outcome after TEVAR. Methods: The study was performed according to the PRISMA guidelines. The PubMed, EMBASE, and Cochrane databases were searched to identify all case series reporting BBC after TEVAR between 2006 and April 2018. Data analysis was performed considering the difference in the risk of complications for presence vs absence of BBC. After screening 1633 articles, 21 studies were identified that matched the selection criteria; 12 of these reported detailed information to investigate the postoperative outcome using proportion meta-analysis with a random effects model. The pooled risk difference is reported with the 95% confidence interval (CI). Heterogeneity of the included studies was assessed with the I2 statistic (low 25%, medium 50%, high 75%). Results: Complications occurred within a range of 0 to 72 months in 14.7% (95% CI 7.4% to 27.3%) of patients with BBC and in 6.3% (95% CI 2.5% to 15.4%) of patients without BBC. A cumulative incidence could not be assessed. The summary risk difference was 11.1% (95% CI -0.1% to 22.3%, p=0.052). There was significant heterogeneity (I2=85.6%). The Egger test did not show evidence of publication bias (p=0.975). When specifically considering type Ia endoleak and endograft migration, the risk difference between BBC and non-BBC patients was 8.2% (95% CI 0.3% to 16.1%, p=0.042; I2=69.0%). The specific risk difference for endograft collapse/infolding and thrombosis was 3.7% (95% CI -3.5% to 11.1%, p=0.308; I2=10.2%). Conclusion: At present the literature does not provide statistical evidence to establish an overall prognostic value of the BBC. Nevertheless, the BBC appears to be associated with a high risk of type Ia endoleak and endograft migration, which warrants specific and long-term surveillance. Clinically relevant values for BBC grading should be established to perhaps define indications for preemptive treatment based on the presence of BBC only.

Effect of Different EndoAnchor Configurations on Aortic Endograft Displacement Resistance: An Experimental Study.

Purpose: This study investigated the effect of different EndoAnchor configurations on aortic endograft displacement resistance in an in vitro model. Materials and Methods: An in vitro model was developed and validated to perform displacement force measurements on different EndoAnchor configurations within an endograft and silicone tube. Five EndoAnchor configurations were created: (1) 6 circumferentially deployed EndoAnchors, (2) 5 EndoAnchors within 120° of the circumference and 1 additional, contralateral EndoAnchor, (3) 4 circumferentially deployed EndoAnchors, (4) 2 rows of 4 circumferentially deployed EndoAnchors, and (5) a configuration of 2 columns of 3 EndoAnchors. An experienced vascular surgeon deployed EndoAnchors under C-arm guidance at the proximal sealing zone of the endograft. A constant force with increments of 1 newton (N) was applied to the distal end of the endograft. The force necessary to displace a part of the endograft by 3 mm was defined as the endograft displacement force (EDF). Two video cameras recorded the measurements. Videos were examined to determine the exact moment 3-mm migration had occurred at part of the endograft. Five measurements were performed after each deployed EndoAnchor for each configuration. Measurements are given as the median and interquartile range (IQR) Q1, Q3. Results: Baseline displacement force measurement of the endograft without EndoAnchors resulted in a median EDF of 5.1 N (IQR 4.8, 5.2). The circumferential distribution of 6 EndoAnchors resulted in a median EDF of 53.7 N (IQR 49.0, 59.0), whereas configurations 2 through 5 demonstrated substantially lower EDFs of 29.0 N (IQR 28.5, 30.1), 24.6 N (IQR 21.9, 27.2), 36.7 N, and 9.6 N (IQR 9.4, 10.0), respectively. Decreasing the distance between the EndoAnchors over the circumference of the endograft increased the displacement resistance. Conclusion: This in vitro study demonstrates the influence EndoAnchor configurations have on the displacement resistance of an aortic endograft. Parts of the endograft where no EndoAnchor has been deployed remain sensitive to migration. In the current model, the only configuration that rivaled a hand-sewn anastomosis was the one with 6 EndoAnchors. A circumferential distribution of EndoAnchors with small distances between EndoAnchors should be pursued, if possible. This study provides a quantification of different EndoAnchor configurations that clinicians may have to adopt in clinical practice, which can help them make a measured decision on where to deploy EndoAnchors to ensure good endograft fixation.

Computational Comparison Between a Classic Bifurcated Endograft and a Customized Model With "Dog Bone"-Shaped Limbs.

PURPOSE: To use computational simulations to compare the hemodynamic characteristics of a classic bifurcated stent-graft to an equally long endograft design with "dog bone"-shaped limbs (DB), which have large diameter proximal and distal ends and significant narrowing at the midsection to accommodate aneurysms with an extremely narrow bifurcation. MATERIALS AND METHODS: A 3-dimensional model was constructed using commercially available validated software. Inlet and outlet diameters were 28 and 14 mm, respectively. The total length of both models was kept constant to 180 mm, but the main body of the DB model was 20 mm shorter than the bifurcated endograft. The iliac limbs of the DB model had a 9-mm stenosis over a 30-mm segmental length in the midsection. Flow was quantified by time-averaged wall shear stress, oscillatory shear index (OSI), and relative residence time (RRT). The displacement forces in newtons (N) and maximum wall shear stress (WSS) in pascals (Pa) were compared during a cardiac cycle at 3 segments (main body, bifurcation, and iliac limbs) of both models with computational fluid dynamics analysis. RESULTS: The DB accommodation was associated with higher forces at the main body (range 3.15-4.9 Ν) compared with the classic configuration (1.56-2.34 N). On the contrary, the forces at the bifurcation (3.81-5.98 vs 3.76-5.54 N) and at the iliac limbs (0.34-0.85 vs 0.49-0.74 N) were comparable for both models. Accordingly, maximum WSS was detected at the iliac sites for both models throughout the cardiac cycle. The highest values were detected at peak systole and equaled 26.6 and 12 Pa for the DB and bifurcated configurations, respectively. The narrow segments in the DB model displayed high stress values but low OSI and very low RRT. CONCLUSION: The DB accommodation seems to correlate with higher displacement forces at the main body and higher stresses at the iliac limbs. Consequently, regular imaging follow-up of the DB design deems necessary to delineate its mid- and long-term clinical performance.

Odyssey of an accidently ingested sewing needle from mouth to mesentery of small bowel in a young female - Case Report.

Foreign body (FB) ingestion is one of the most common complaint in the emergency room and, extra-intestinal migration of penetrating sharp FBs is one of the most overlooked aspect of medical research. We report a case of accidental ingestion of a sewing needle which was recovered from the mesentery. The 28-year-old female presented to our hospital with abdominal pain and one-month's history of needle ingestion. Initially laparoscopy was performed, which was inconclusive. Afterward, through laparotomy, the needle was successfully removed from the mesentery of small bowel.

Exploring pyloric dynamics in stenting using a distensibility technique.

BACKGROUND: Perforated duodenal ulcers can be treated with a covered stent. Stent migration is a severe complication, sometimes requiring surgery. Pyloric physiology during stent treatment has not been studied and mechanisms for migration are unknown. The aim of this study was to investigate the pyloric response to distention, mimicking stent treatment, using the EndoFLIP. METHODS: A nonsurvival study in five pigs was carried out, followed by a pilot study in one volunteer. Animals were gastroscoped during anaesthesia and the EndoFLIP was placed straddling the pylorus. Baseline distensibility readings were performed at stepwise balloon distentions to 20, 30, 40, and 50 mL, measuring pyloric cross-sectional area and pressure. Measurements were repeated after administration of a prokinetic drug and after a liquid meal. In the human study, readings were performed in conscious sedation at baseline and after stimulation with metoclopramide. KEY RESULTS: During baseline readings, the pylorus was shown to open more with increasing distention together with higher amplitude motility waves. Reaching maximum distention-volume (50 mL), pyloric pressure increased significantly (P = 0.016), and motility waves disappeared. After prokinetic stimulation, the pressure decreased and the motility waves increased in frequency and amplitude. After food stimulation, the pressure stayed low and the motility showed increase in amplitude. During both tests, the pylorus showed higher pressure and lack of motility waves at maximum probe distention. CONCLUSIONS AND INFERENCES: The pylorus seems to act as a sphincter at low distention but when further dilated starts acting as a pump. Fully distended the pyloric motility disappears and the pressure remains high, suggesting that a stent with high-radial force might show less migration.

Calculation of iris-claw IOL power for correction of late in-the-bag IOL complex dislocation.

BACKGROUND: To assess the constants and formula for aphakia correction with iris-claw IOLs to achieve the best refractive status in cases of late in-the-bag IOL complex dislocation. METHODS: A literature search was performed. The following data were obtained: Iris-claw IOL model, Iridal or retroiridal enclavation, A-constant, ultrasound or optical biometry, formula employed and refractive outcomes. Acceptable emmetropia was considered if the resulting spherical equivalent (SE) was within ±1.00 D. RESULTS: The majority of the studies used SRK/T formula (66.6%). The 88.9% of the reports obtained a SE within ±1.00 D. Using A-115 for ultrasound biometry and A-115.7 for optical biometry and SRK/T formula, the emmetropia (±1.00 D) of SE, was able to get near 100% of reported cases over the pupil implantation. However, the emmetropia decreased to 80% when the enclavation is retropupilar using the same formula. The A-constant can vary from 116.7 to 117.5 for retropupilar enclavation. CONCLUSIONS: Using A-115 for ultrasound biometry and A-115.7 for optical biometry and SRK/T formula, ±1.00 D of SE, is able to get near 100% of cases. Nevertheless, ±1.00 D of SE decreased to 80% of the cases when the enclavation is retropupilar.

Transcatheter Aortic Valve Implantation as a Bailout Procedure for Acute Aortic Valve Regurgitation During Endovascular Arch Repair.

PURPOSE: To report emergent transcatheter aortic valve implantation (TAVI) to treat acute severe aortic regurgitation caused by valve cusp dysfunction following proximal migration of an endograft implanted in the ascending aorta during endovascular arch repair. CASE REPORT: A 65-year-old man had been previously treated with thoracic and fenestrated endografts in a 2-stage procedure for a chronic type B dissection. At 2-year follow-up, aneurysmal evolution of the distal arch led to development of a proximal type Ia endoleak. The patient was deemed unfit for open repair because of severe nonrevascularizable coronary artery disease. A custom-made endograft was designed consisting of a double inner branch arch endograft with a proximal component to reline the ascending aorta to avoid iatrogenic type A dissection. The first component was successfully deployed. However, this device migrated toward the aortic valve when the delivery system of the branch device was advanced through the aortic valve. Aortography and transesophageal echography showed acute aortic regurgitation due to obstruction of the left coronary valve cusp. An emergency bailout TAVI procedure was performed to successfully treat the aortic regurgitation. CONCLUSION: TAVI can be used as a bailout procedure for acute aortic valve dysfunction during endovascular arch or ascending aorta repair.

Fractured Superior Mesenteric Artery Stent With Stent Displacement Leading to Recurrent Symptoms of Superior Mesenteric Ischemia.

We report a case of a patient with recurrent symptoms of superior mesenteric ischemia 7 months after successful percutaneous angioplasty and implantation of a stent in the superior mesenteric artery (SMA). Stent fracture and stent displacement were observed. To the best of our knowledge, this is the first report of SMA stent fracture with stent displacement.

Asymptomatic migration of an AMPLATZER™ Amulet™ left atrial appendage occluder through the mitral valve.

An 84-year-old woman with a history of hemorrhagic stroke was admitted for a new cerebral ischemic event. While in hospital, she was diagnosed with paroxysmal atrial fibrillation. Owing to her high thromboembolic risk (CHA2 DS2 -VASc score of 6) we performed left atrial appendage (LAA) closure using a 22-mm AMPLATZER™ Amulet™. The procedure was successful. Systematic follow-up with transthoracic echocardiography 8 hr later revealed that the LAA occluder had migrated and become entrapped in the mitral subvalvular apparatus. At this time, the patient was asymptomatic. The device was recovered percutaneously using a loop-snare catheter, with no further complications. © 2016 Wiley Periodicals, Inc.

Changes in electromyographic amplitudes but not latencies occur with endotracheal tube malpositioning during intraoperative monitoring for thyroid surgery: Implications for guidelines.

OBJECTIVES/HYPOTHESIS: During intraoperative neural monitoring (IONM) in thyroid and parathyroid surgery, endotracheal (ET) tube migration can result in a decrease in vocalis electromyographic (EMG) amplitude without a concordant latency elevation during stimulation of the recurrent laryngeal nerve (RLN). STUDY DESIGN: Retrospective review. METHODS: Data were reviewed retrospectively for thyroid and parathyroid surgery patients with IONM of the laryngeal nerves from January 2015 to December 2015. Recordings of vocalis EMG amplitudes and latencies with RLN stimulation were obtained with the neuromonitoring ET tube surface electrodes in optimal baseline position, with vertical displacement away from the vocalis, and with rotational change away from baseline. RESULTS: ET tube surface electrode EMG recordings were obtained with stimulation of seven left and three right RLNs in a total of 10 patients. Mean vocalis EMG amplitudes were reduced with vertical displacement 1 and 2 cm both inferior and superior to baseline and with rotational change (45° and 90° clockwise and counterclockwise, 180°), although amplitude change with 45° clockwise and 180° rotation did not meet statistical significance. Mean EMG latency values did not change significantly from baseline with either rotation or vertical displacement of the ET tube. CONCLUSIONS: An isolated decrease in EMG amplitude without concordant latency elevation should warrant re-evaluation of ET tube position during thyroid and parathyroid surgery and is in contrast to a combined event, with both EMG amplitude decrease and concordant latency increase, which is more suggestive of a true neuropraxic injury. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2182-2188, 2017.