Elika Kashef

Advanced Catheter Technology: Is This the Answer to Overcoming the Long Learning Curve in Complex Endovascular Procedures

INTRODUCTION Advanced endovascular procedures require a high degree of skill with a long learning curve. We aimed to identify differential increases in endovascular skill acquisition in novices using conventional (CC), manually steerable (MSC) and robotic endovascular catheters (RC). MATERIALS/METHODS 10 novices cannulated all vessels within a CT-reconstructed pulsatile-flow arch phantom in the Simulated Endovascular Suite. Subjects were randomly assigned to conventional/manually-steerable/robotic techniques as the first procedure undertaken. The operators repeated the task weekly for 5 weeks. Quantitative (cannulation times, wire/catheter-tip movements, vessel wall hits) and qualitative metrics (validated rating scale (IC3ST)) were compared. RESULTS Subjects exhibited statistically significant differences when comparing initial to final performance for total procedure times and catheter-tip movements with all catheter types. Sequential non-parametric comparisons identified learning curve plateau levels at weeks 2 or 3(RCs, MSCs), and at week 4(CCs) for the majority of metrics. There were significantly fewer catheter-tip movements using advanced catheter technology after training (Week 5: CC 74 IQR(59-89) versus MSC 62(44-81); p = 0.028, and RC 33 (28-44); p = 0.012). RCs virtually eliminated wall hits at the arch (CC 29(28-76) versus RC 8(6-9); p = 0.005) and produced significantly higher overall performance scores (p < 0.02). CONCLUSION Advanced endovascular catheters, although more intricate, do not seem to take longer to master and in some areas offer clear advantages with regards to positional control, at a faster rate. RCs seem to be the most intuitive and advanced skill acquisition occurs with minimal training. Robotic endovascular technology may have a significantly shorter path to proficiency allowing an increased number of trainees to attempt more complex endovascular procedures earlier and with a greater degree of safety.

Reducing Error and Improving Efficiency during Vascular Interventional Radiology: Implementation of a Preprocedural Team Rehearsal

PURPOSE To determine the type and frequency of errors during vascular interventional radiology (VIR) and design and implement an intervention to reduce error and improve efficiency in this setting. MATERIALS AND METHODS Ethical guidance was sought from the Research Services Department at Imperial College London. Informed consent was not obtained. Field notes were recorded during 55 VIR procedures by a single observer. Two blinded assessors identified failures from field notes and categorized them into one or more errors by using a 22-part classification system. The potential to cause harm, disruption to procedural flow, and preventability of each failure was determined. A preprocedural team rehearsal (PPTR) was then designed and implemented to target frequent preventable potential failures. Thirty-three procedures were observed subsequently to determine the efficacy of the PPTR. Nonparametric statistical analysis was used to determine the effect of intervention on potential failure rates, potential to cause harm and procedural flow disruption scores (Mann-Whitney U test), and number of preventable failures (Fisher exact test). RESULTS Before intervention, 1197 potential failures were recorded, of which 54.6% were preventable. A total of 2040 errors were deemed to have occurred to produce these failures. Planning error (19.7%), staff absence (16.2%), equipment unavailability (12.2%), communication error (11.2%), and lack of safety consciousness (6.1%) were the most frequent errors, accounting for 65.4% of the total. After intervention, 352 potential failures were recorded. Classification resulted in 477 errors. Preventable failures decreased from 54.6% to 27.3% (P < .001) with implementation of PPTR. Potential failure rates per hour decreased from 18.8 to 9.2 (P < .001), with no increase in potential to cause harm or procedural flow disruption per failure. CONCLUSION Failures during VIR procedures are largely because of ineffective planning, communication error, and equipment difficulties, rather than a result of technical or patient-related issues. Many of these potential failures are preventable. A PPTR is an effective means of targeting frequent preventable failures, reducing procedural delays and improving patient safety.

Endovascular Repair of an Acute, Mycotic, Ascending Aortic Pseudoaneurysm

This report describes endovascular stenting of an acute mycotic ascending aortic aneurysm. An eighty-three year old lady presented nine weeks after aortic valve surgery and subsequent thyroidectomy with sternal pain secondary to a mycotic ascending aortic pseudoaneurysm. The pseudoaneurysm was visible through the unhealed sternum. Open repair was considered too high a mortality risk. Endovascular stenting was performed using two covered infrarenal proximal extension devices (GORE Excluder Aortic Extender(®), W. L. Gore & Associates, Flagstaff, Arizona, USA) deployed from a right axillary approach utilising overdrive cardiac pacing. Post procedure imaging revealed shrinkage of the pseudoaneurysm sac.

Endovascular treatment of thoracic aortic aneurysms with a short proximal landing zone using scalloped endografts

BACKGROUND The suitability of the proximal landing zone remains one of the main limitations to thoracic endovascular aortic repair (TEVAR). The advent of custom-made scalloped stent grafts widens the endovascular options for patients with challenging anatomy. The objective of this study was to present our early and midterm results of custom-made scalloped thoracic stent grafts. METHODS Prospectively acquired data relating to patient demographics, procedure details, clinical outcome, and complications were analyzed. In addition, we analyzed preoperative and postoperative computed tomography scans to evaluate aneurysm morphology, graft placement, side-vessel patency, and endoleaks. RESULTS Twenty-one patients with a median age of 71 years (range, 35-81 years) underwent custom-made scalloped TEVAR, eight of whom had a concomitant hybrid repair. Procedural success was achieved in all cases. Proximal seal was achieved in all cases, with no type I endoleaks. There were no cases of retrograde dissection and no conversions to open repair. The median follow-up period was 36 weeks (range, 3-183 weeks). Two patients died in the hospital. Three patients suffered a stroke. Three patients had a type II endoleak, one of whom had significant sac enlargement requiring reintervention. One patient had a type III endoleak requiring reintervention. There were no cases of graft migration. CONCLUSIONS Our midterm results show that custom-made scalloped TEVAR is an acceptable treatment of thoracic aortic aneurysms with a short proximal landing zone. Longer term outcome data are required to establish wider use of scalloped thoracic endografts.

Scalloped Thoracic Stent-Graft for Treatment of Aortic Arch Aneurysms With Unfavourable Landing Zones

Endovascular treatments are limited in cases of thoracic aortic aneurysms extending up or proximal to the origin of the left subclavian artery (LSCA). In such cases, the LSCA is usually either occluded or revascularised. We report our first experience of four patients who underwent thoracic aneursym treatment with new custom-made grafts with a scallop in situ for the LSCA. The graft is tailor made per case, and a re-enforced scallop is positioned proximally allowing for the stent to be deployed beyond the origin of the LSCA; the origin of the LSCA remains patent, thus negating the need for revascularisation of the head and neck vessels on the left. The stent contains markers for identifying the scallop and are located along the midline to ensure correct alignment. All of the patients who underwent this procedure had technical success with flow through the LSCA both immediately after stent deployment and on follow-up imaging. This new stent has further expanded endovascular treatment options for patients with thoracic aneurysms extending up to and beyond the LSCA, which can play a part in improving outcome and decreasing mortality rates because surgery for revascularization will not be needed.

New-generation stent grafts for endovascular management of thoracic pseudoaneurysms after aortic coarctation repair

OBJECTIVE Late thoracic aneurysms develop in 5% to 12% of patients having undergone open repair for coarctation of the aorta (CoA). We report our early results for thoracic endovascular aortic repair for pseudoaneurysms after CoA repair. METHODS From 2008 to 2013, data regarding demographics, aneurysm morphology, procedure, and follow-up were collected prospectively on all patients treated for pseudoaneurysms after CoA repair. Retrospective analysis of identified patients was then performed. RESULTS Thirteen patients (six men, seven women) were treated. Patients were a median age, 45 years (interquartile range (IQR), 39-56; range, 27-66 years, and the median time after CoA repair to aneurysm treatment was 34 years (IQR, 24-40 years). All patients had saccular pseudoaneurysms of the aortic arch, with a median aneurysm size of 4.1 cm (IQR, 3.4-5.1 cm). The left subclavian artery (LSCA) was involved in 10 patients and was occluded at presentation in three. Four patients had concurrent LSCA revascularization with carotid-subclavian bypass, one had aortic arch hybrid repair, and the LSCA was intentionally covered in two patients. Patients underwent thoracic endovascular aortic repair using the conformable TAG (6 of 13; W. L. Gore & Associates, Flagstaff, Ariz), Valiant device (4 of 13; Medtronic, Minneapolis, Minn), and a custom-made Relay endograft with LSCA scallop (4 of 13; Bolton Medical, Barcelona, Spain). Technical success was 100%, with satisfactory deployment of the stent grafts in all patients. There was no 30-day mortality, stroke, or paraplegia. Median follow-up was 15 months (IQR, 9-19 months; range, 1-67 months). Two type II endoleaks from an intercostal artery were managed conservatively, and one type Ib endoleak was treated successfully with distal stent extension. CONCLUSIONS In this cohort, new-generation stent grafts have good early clinical and radiologic outcomes, avoiding the need for redo open surgery. Management of the LSCA can be tailored to individual patients with new stent graft technology. Long-term follow-up of these patients is crucial to understanding whether endovascular management of this cohort is acceptable.

The Midterm Experience of Tapered Stent Grafts in the Endovascular Management of Iliac Artery Aneurysms With Unfavorable Anatomy

We report our experience and the midterm results of a modern technique for endovascular management of isolated iliac artery aneurysms (IAAs) with unfavorable neck anatomy, which involves the inversion of an iliac leg of a Zenith stent graft. Patients who underwent endovascular IAA repair from 2002 to 2010 were reviewed. A total of 12 patients, with a mean age of 77.6 years, underwent endovascular repair of 13 IAAs. Mean size of the aneurysms was 54.6 mm (range 34-133 mm). Mean proximal neck diameter was 18 mm (range 15-22 mm). In 7 patients, the length of the proximal neck was <15 mm (10-14 mm). Only 1 patient developed thrombosis of the stent graft immediately after the operation. Patients were followed up for a mean of 31.5 months (range 18-72 months). Our midterm results demonstrate the durability of this technique in the management of iliac aneurysms with unfavorable anatomy.

Use of advanced imaging techniques during visits to emergency departments--implications, costs, patient benefits/risks.

25 years ago, on a Friday evening at 9 pm, the emergency department (ED) was full of patients with a wide range of clinical problems. Their investigations included plain radiographs, but no other imaging was included until the next working day. At present, many patients are receiving advanced imaging such as ultrasound, CT and MRI, often delivered out of hours--an obvious advance for patients or sometimes an unnecessary development? In this article, we will consider how to assess patient benefits and whether increased use of advanced imaging is an overall advance for patients. We will address the general implications for healthcare services which come with greater use of advanced imaging. We will then address the effect of advanced imaging on individual fictional ED patients with a variety of complaints.

Staged open, endovascular, and hybrid repair of concomitant mycotic aneurysms.

Primary mycotic aneurysms of the aorta are a rare but life-threatening condition. A 59-year-old woman developed a back abscess secondary to an insect bite. A computed tomography scan revealed 3 concomitant mycotic aneurysms, including a rupture. Staged repair was undertaken: immediate open repair for contained rupture of a type IV thoracoabdominal aortic aneurysm, followed by endovascular repair of a descending thoracic aneurysm 3 weeks later and finally an aortic arch hybrid repair of a left subclavian artery aneurysm 16 months later. She remains well postoperatively. There is currently no consensus on the timing of repair or modality of treatment of mycotic aneurysms. Each patient should be treated individually based on aneurysm location, rupture, and comorbidities, as shown by this case.

Trauma in the elderly patient

Major Trauma Centres and Emergency Departments are treating an increasing number of elderly trauma patients in the UK. Elderly patients, defined as those over the age of 65 years, are more susceptible to injury from lesser mechanisms of trauma than younger adults. The number of elderly trauma cases is rising yearly, accounting for >25% of all major trauma nationally. The elderly have different physiological reserves and a different response to trauma due to premorbid frailty, co-existing conditions and prescribed medication. These factors need to be appreciated in trauma triaging, radiological assessment and clinical management. A lower threshold for trauma-call activation is recommended, including a lower threshold for advanced imaging. We will review general principles of trauma in the elderly, outline injury patterns in this age group and illustrate the radiological features per anatomical site, from head to pelvis and the extremities. We advocate using contrast-enhanced computed tomography as the primary diagnostic imaging modality as concern about intravenous contrast agent-induced nephropathy is relatively minor. Prompt investigation and diagnosis leads to timely appropriate treatment, therefore the radiologist can discerningly improve morbidity and mortality in this vulnerable group.