Bypass Creation Research Articles

Low-flow extra-intracranial bypass in acute carotid and vertebrobasilar ischemic stroke (literature review)

Introduction. The effectiveness of the method of revascularization of the brain using extra‑intracranial bypass in chronic insufficiency of blood supply to the brain has been studied in several randomized multicenter studies. The analysis of available publications devoted to this technique for 10 years with acute strokes in the carotid basin and for 20 years with ischemic strokes in the vertebrobasilar basin was carried out.Aim. To improve the results of treatment of ischemic strokes with the help of emergency extra‑intracranial low‑flow bypasses in the acute and acute period. In 12 publications over the past 10 years, selected from the PubMed search engine, 194 cases of the use of emergency extra‑intracranial microbypasses in the acute and acute period of ischemic stroke in the carotid basin were identified, 127 cases of emergency extra‑intracranial bypass were found in 6 articles during the last 20 years in the acute phase of vertebra‑basilar area stroke. Middle patient age in carotid group was 61.9 years, and 65 years in vertebral patient’s group. The male / female ratio was 3 / 1. The main indications for the bypass creation were: worsening of neurologic deficit from 4 and more according to the Stroke Severity Scale of the US National Institutes of Health, mini mal or not significant computed tomography (CT) or diffusion‑weighted magnetic resonance imaging (DW‑MRI) ischemia brain changes (not lower than 8 points on the scale of assessment of initial changes in the computed tomographic (CT) examination for stroke Alberta Stroke Program Early CT Score, ASPECTS), signs of significant brachiocephalic arteries atherosclerotic stenosis. In 83 carotid group cases perfusion‑diffusion mismatch was distinguished before bypass creation. In 111 carotid cases and in priority of vertebra‑basilar cases clinic‑diffusion mismatch was the only indication for emergency extra‑intracranial bypass creation. During the first 24 hours 65 % of carotid group bypass were performed, in other 35 % of cases bypasses were performed during 1 week after the stroke onset. There were 78 % of good results (<2 on the Rankin outcome scale, mRS) and 22 % of poor (mRS >2) in carotid stroke group. Mortality was 3 %. In vertebral group, coma was not contraindication for emergence extra‑intracranial bypass creation. In most cases, 70 % of bypass were performed between superficial temporal artery and superior cerebellar artery. Mortality in vertebral stroke group was 5 %, mostly because of somatic pathology worsening. Good results were achieved in76 % of cases.Conclusion. In some cases of atherosclerotic carotid and vertebrobasilar ischemic stroke, results of recovery can be approved greatly with use of emergency low‑flow extra‑intracranial bypass, if intravenous thrombolysis and endovascular tromboextraction were failed.

Endoscopic entero-enteral bypass to treat postsurgical benign complications of hepatico-jejunostomy: Update of a 7-year single-center experience

Background and study aims Since 2014, we have been using a new endoscopic approach to improve management of biliary adverse events (BAEs) after bilio-digestive anastomosis. We provide an update about our experience at 7 years. Patients and methods Patients with BAEs on hepatico-jejunostomy underwent entero-enteral endoscopic by-pass (EEEB) creation between the duodenal/gastric wall and the biliary jejunal loop. Evaluation of results during our seven-year experience was performed. Results Eighty consecutive patients (32 patients from Jan 2014 to Dec 2017 and 48 patients from Jan 2018 to Jan 2021) underwent EEEB, which was successful in all but one patient. The cumulative AEs rate was 32 %. Endoscopic retrograde cholangiography (ERC) through the EEEB successfully treated all types of BAEs in these patients. Cumulative disease recurrence was 3.8 % (three patients) and was retreated through the EEEB. Conclusions The update of our experience with EEEB confirmed that in patients with BAEs after bilio-digestive anastomosis, EEEB allows successful long-term treatment of different BAEs in a tertiary referral center with an acceptable rate of related AEs.

Human Thrombin–Gelatin Matrix With Rifampin: Novel Technique for Treating Vascular Graft Infections

Approximately 1% to 6% of prosthetic vascular grafts will be complicated by infections. However, the mortality rates range from 17% to 40%, and morbidity is also high, including reinfection rates reported at 18% and limb loss close to 11%. Early aggressive surgical management, including graft excision and wide wound debridement with extra-anatomic bypass creation is the reference standard. Graft preservation techniques have been increasingly used, with high cure rates. Muscle flap, coverage, and antibiotic-coated absorbable and nonabsorbable beads have been reported to provide high cure rates but, owing to the associated technical difficulties, with suboptimal graft salvage rates.

Human Thrombin–Gelatin Matrix With Rifampin: A Novel Technique for Treating Vascular Graft Infections

Approximately 1% to 6% of prosthetic vascular grafts will be complicated by infection. However, the mortality rates have ranged from 17% to 40%, and the morbidity is also high, including reinfection rates reported at 18% and limb loss close to 11%. Early aggressive surgical management, including graft excision and wide wound debridement with extra-anatomic bypass creation is the reference standard. Graft preservation techniques have been increasingly used, with high cure rates. Muscle flap, coverage, and antibiotic-coated absorbable and nonabsorbable beads have been reported to provide high cure rates but with associated technical difficulties and suboptimal graft salvage rates. We implemented a novel technique for localized antibiotic therapy using a human thrombin–gelatin matrix with rifampin (HTGM+R) at our institution for the past 5 years (Figs 1 and 2). We have described the rates of graft salvage, reintervention, limb salvage, and infection recurrence. We performed a retrospective cohort study of patients who had presented with prosthetic vascular graft infection from January 2016 through June 2021 and had been treated using our novel technique. Statistical analysis included descriptive frequencies of the demographic variables and outcomes of interest. A total number of 16 patients with a total of 32 interventions were included in the present study. Approximately 76.5% had required two or more interventions. HGTM+R was used for 15 interventions (46.9%) in 14 patients. Thrombectomy was the second most common intervention (n = 11; 34.4%). The mean age was 65.2 years, and the mean body mass index was 26.7 kg/m2. The common comorbidities are shown in the Table. The graft salvage rate was 80%, the limb salvage rate was 93.3%, and the freedom from infection rate was 86.7% for HGTM+R. However, the reintervention rate was 28.6%. Only four patients had required graft excision at an average follow-up of 12 months. Hypertension was the most common comorbidity, followed by diabetes and steroid use. Finally, no association with specific bacteria was seen. To date and to the best of our knowledge, the present study is the only study to describe this novel technique for treating prosthetic vascular graft infections. Moreover, it is the only study to describe the outcomes of HGTM+R in the treatment of prosthetic vascular graft infection.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Are Small Popliteal Aneurysm so Innocent?

We recently recorded 5 lower limb ischemia related to a small (diameter≤20 mm) popliteal artery aneurysm (PAA) thrombosis hence we performed a retrospective data analysis on small symptomatic PAA management from our database. We performed a retrospective cohort study on 48 acute leg ischemia from aneurysm's thrombosis. All of them underwent surgical distal thrombectomy and bypass creation. Patients were divided into 2 different cohorts: GROUP A (diameter ≥20 mm) and GROUP B (diameter ≤20 mm). Differences in terms of the limb salvage (end-point: the amputation rate) was analyzed and considered significative for P ≤ 0.05. Secondary objectives were: vessel runoff recovery and patency rate. Adverse events were collected at 12 and 24 months postoperative. Two-year overall amputation rate was: 22.9% (11/48); 21.8% (7/32) in GROUP A and 25% (4/16) in GROUP B (RR:0.87, CI:0.29-2.55, p.80). The mean age was 68 ± 13 years, No statistically significant differences were identified in term of primary and secondary patency (RR:0.95, CI:0.55-1.6, p.85 and (RR:0.95, CI:0.53-1.7, p.88 respectively) no differences were found in terms of comorbidities. Patients' follow-up ranged from 8 to 36 months. In 90% of those amputated patients, the length of ischemia exceeded 4 days. Amputation rate was correlated with one runoff vessel recovery, only. s According these results small PAA are not as innocent as it is often presumed and was associated with not negligible incidence of limb loss due to thrombosis or distal embolizations also if compared to larger aneurysm. The immediate surgery is mandatory also when the ischemia exceeds 2 days.

Percutaneous embolization of a ruptured mycotic visceral aortic aneurysm stump hemorrhage

Introduction and Objective Managing infected endovascular aortic stent grafts is difficult and often has morbid consequences. We report a complicated case of endovascular aortic stent graft infection treated through complex surgical and endovascular management. A standard attempt at open surgical correction was made, however, due to the complex nature of the patient's condition; much of the treatment accomplishedvia endovascular techniques for ultimate resolution. Case Report Graphical AbstractA) CTA maximum intensity projection after initial surgical repair demonstrating an axillary-femoral and femoral-femoral bypass creation (star), distal aortic and bilateral artery ligation (asterisks). B) Sagittal abdominal CTA 2 weeks after initial surgery demonstrating contrast extravasation from the aortic stump (arrow). View Large Image Figure Viewer Download Hi-res image Graphical AbstractA) Posterior projection of a volume rendered CTA after the second surgical repair demonstrating distal thoracic aorta ligation (open arrow), previous ligations (asterisks), bypass grafts from the distal thoracic aorta to the SMA (white arrow), splenic artery (open arrowhead), and left renal artery (white arrowhead). B) Sagittal abdominal CTA demonstrating recurrent hemorrhage in the visceral aorta (arrow), with themultiple ligations (asterisks) of the aorta and SMA, as well as the celiac bypass (arrowhead). View Large Image Figure Viewer Download Hi-res image Graphical AbstractA) Oblique image of the aortic stump access using an 18-gauge Hawkins needle (Cook, Bloomington, IN) (white arrowheads) shows inflow at the celiac ostium as a contrast void (white circle), opacification of the replaced right hepatic (black arrow), right renal artery (black arrowhead), and visceral aorta with extravasation of contrast (white arrow). B) SOS 2 catheter (Cook, Bloomington, IN) selection of the celiac artery (white arrow head) with retrograde flow in to the aortic lumen (white circle), inflow from the splenic artery stump bypass (black arrowhead), and antegrade flow into the common hepatic artery (black arrow). View Large Image Figure Viewer Download Hi-res image Graphical AbstractThe ostia of the celiac artery, right renal artery, and direct aortic origin right hepatic celiacartery origin were embolized using multiple techniques. A) A 0.24 microcatheter (white arrowhead) was advanced into the splenic artery and used to place an Amplatz IV (6 × 11mm) (St. Jude Medical, St. Paul, MN) (black arrowhead) into the ostium of the celiac artery to exclude the aortic stump but preserve hepatic arterial supply. Direction of blood flow from the splenic bypass towards the celiac ostium and into the common hepatic artery is demarcated with open arrows. B) The replaced right hepatic artery was embolized with multiple 0.018 6mm and 4mm detachable coils (Boston Scientific S Interlock, Marlboro, MA) (arrow). C) The visceral aortic lumen and right renal artery were embolized with 0.035 and 0.018 detachable coils (Boston Scientific S Interlock, Marlboro, MA), a 0.035 Benson wire with removed mandrel (Cook,Bloomington, IN) and n-BCA glue (TruFill Johnson and Johnson, Miami, FL). The aortic access track was then closed with an 8mm Amplatz plug and n-BCA glue (arrowhead). View Large Image Figure Viewer Download Hi-res image Graphical AbstractA) 3-year post-operative follow up 3D rendered image showing patents bypasses to the SMA (white arrow), splenic artery (open arrowhead), and left renal artery (white arrowhead), stable ligation of the distal thoracic aorta and embolized visceral abdominal aorta. B) 3-year post-operative sagittal CT showing absence of perfusion to the visceral aortic (arrow). View Large Image Figure Viewer Download Hi-res image Discussion Complex aortic surgery is challenging especially in the presence of recurrent infection. This case was a unique situation in which a less invasive endovascular correction was successful for a patient with multiple recent aortic surgeries in which perioperative mortality for any additional surgeries was likely. Managing infected endovascular aortic stent grafts is difficult and often has morbid consequences. We report a complicated case of endovascular aortic stent graft infection treated through complex surgical and endovascular management. A standard attempt at open surgical correction was made, however, due to the complex nature of the patient's condition; much of the treatment accomplishedvia endovascular techniques for ultimate resolution. Complex aortic surgery is challenging especially in the presence of recurrent infection. This case was a unique situation in which a less invasive endovascular correction was successful for a patient with multiple recent aortic surgeries in which perioperative mortality for any additional surgeries was likely.

Feasibility and Outcomes of Femoral Vein Harvest for Dialysis Access and Arterial Reconstruction

BackgroundWe describe the feasibility and long-term outcomes of using femoral vein (FV) for arteriovenous fistula (AVF) and lower extremity bypass (LEB) creation. MethodsAll patients undergoing AVF or LEB using autogenous FV by a single surgeon (April 2006 to September 2013) were reviewed. Perioperative (30-d) complications and long-term outcomes are described. ResultsForty-four patients underwent vascular reconstruction with FV (AVF = 27 and LEB = 17). Perioperative morbidity was 43.2%, including harvest site infection and or seroma in 15.9%. No patients suffered from compartment syndrome or venous thromboembolic event. At median follow-up of 50.0 mon, overall patency was 70.4% for AVF (primary = 37.0% and secondary = 70.3%) and 76.5% for LEB (primary = 70.6% and secondary = 76.5%). Long-term lower extremity swelling occurred in 18.2% of patients. ConclusionsPerioperative morbidity following FV harvest is high, but long-term patency rates are excellent. FV harvest is feasible and should be considered as a valid conduit in patients without useable great saphenous vein or other more commonly used sources of autogenous vein.

Preclinical success but clinical failure of the sutureless excimer laser-assisted non-occlusive anastomosis (SELANA) slide

BackgroundThe excimer laser-assisted non-occlusive anastomosis (ELANA) has been developed for intracranial bypass without the need for temporary recipient occlusion. We designed and tested a sutureless variant of the ELANA—the SELANA slide (SEsl).ObjectiveThis study aims to evaluate the SEsl preclinical results and describe its first clinical application.MethodsFirst, in a cadaver study, 28 SEsl anastomoses were compared with 28 ELANA anastomoses. Second, in an acute rabbit model, 90 SEsl anastomoses were compared with 30 ELANA anastomoses. Finally, in a surviving pig model, 38 SEsl bypasses were created. To evaluate the clinical efficacy of the SEsl, we then treated one patient with a giant, right-sided middle cerebral artery (MCA) aneurysm with an intracranial–intracranial SEsl bypass and parent vessel occlusion.ResultsIn preclinical studies, the SEsl anastomosis was shown to be equivalent or superior to the ELANA in terms of associated ease, patency, and bleeding complications. However, clinical application in rigid and arteriosclerotic receiving arteries was problematic. Although bypass creation and aneurysm occlusion were technically successful and the patient was postoperatively well, a pseudoaneurysm formed postoperatively at the internal carotid artery anastomosis and bled. Subsequent treatment failed and the patient did not survive.ConclusionThe SEsl showed promising preclinical results across three models. However, in its present form, it is not suitable for clinical application.Trial numberIRB UMCU 10/154.

EXPERIENCE OF EXTRACRANIAL-INTRACRANIAL BYPASS WITH USING MAXILLARY ARTERY

Objective is to present the first experience of creating extracranial-intracranial (EC-IC) bypass using the maxillary artery (MA) as an arterial donor for treatment of giant intracranial aneurysms (GIA), as well as for treatment of internal carotid artery (ICA) occlusion. Materials and methods. We performed EC-IC bypasses using MA at 4 patients: at 3 patients with GIA of the anterior part of the Willis circle (giant fusiform aneurysm of the М1 segment of middle cerebral artery (MCA), giant fusiform aneurysm of the supraclinoid part of ICA, giant ICA bifurcation aneurysm) and at patient with ICA occlusion. All patients with aneurysms had tumor-like clinical manifestation. Patient with ICA occlusion had crescendo ipsilateral MCA transient ischemic attacks. Creation of the traditional EC-IC bypass was impossible because of superficial temporal artery injury as result of prior surgery in other hospital. Results. We used transzygomatic pterional craniotomy, MA as a donor artery, M2 segment of MCA as a recipient artery and radial artery as an interposition graft in all cases. At patient with ICA occlusion surgical treatment included bypass creation, at all patients with GIA after bypass creation we performed aneurysm trapping (distal clipping of М1 segment at patient with MCA aneurysm, cervical ICA ligation at patient with supraclinoid ICA GIA, temporary trapping, thrombectomy and aneurysm clipping at patient with bifurcation ICA GIA). We confirmed bypass patency by intraoperative Doppler sonography and flowmetry and computed tomography or magnetic resonance imaging in postoperative period. In all cases bypasses were patent with flow 33–57 ml per min. Patient with ICA bifurcation GIA suffered from contralateral hemiparesis due to ischemia in anterior choroid artery territory in early postoperative period, which partially regressed at discharge. In other cases there were not any complications. Conclusion. EC-IC bypasses with using MA as a donor and radial artery as an interposition graft can provide sufficient replacement blood flow in the MCA territory in cases of giant cerebral aneurysms and in patients with occlusion of the ICA. This type of bypasses is less traumatic compared with high-flow bypasses. Given the shorter length and less tortuosity of the graft, its more secure localization, we can assume a lower risk of bypass thrombosis in the early and late postoperative periods and higher patency of the graft.

Survivable automatic hidden bypasses in Software-Defined Networks

The paper focuses on the problem of effective and resilient network resources management under condition of increasing Internet traffic. Multilayer automatic optical networks are considered as a solution usually indicated as the most appropriate for the future Internet. In this paper, we propose a Survivable Automatic Hidden Bypasses approach to enhance resource utilization and reliability in multilayer optical networks. Our solution uses the Software-Defined Networking concept to automatically create or remove hidden bypasses which are not visible at the network layer. We propose a novel survivability metric which is applied during optical bypass creation in order to handle network failures in a proactive manner. Such an approach contrasts with the most common one where bypasses are considered as a mechanism to handle network failures. We combine the metric with different restoration schemas and investigate the proposed mechanism under three failure scenarios. The mechanism of hidden bypasses increases throughput and reduces transmission delays while novel proactive survivability mechanisms neutralize negative impact of network failures.

Minimally invasive entero-enteral dual-path bypass using self-assembling magnets.

A minimally invasive method of entero-enteral bypass may be desirable for treatment of obstruction, obesity, or metabolic syndrome. We have developed a technology based on miniature self-assembling magnets which create large-caliber anastomoses (incisionless anastomosis system or IAS). The aim of this study was to assess (a) procedural characteristics of IAS deployment and (b) long-term integrity and patency of the resulting jejuno-ileal dual-path bypass. Endoscopic jejuno-ileal bypass creation using IAS magnets was performed in 8 Yorkshire pigs survived 3months. The jejunal magnet was endoscopically deployed. However, the ileal magnet required surgical delivery given restraints of porcine anatomy. A 5-mm enterotomy was created through which the ileal magnet was inserted using a modified laparoscopic delivery tool. Magnets were manually coupled. Pigs underwent serial endoscopies for anastomosis assessment. Three-month necropsies were performed, followed by pressure testing of anastomoses and histological analysis. Jejuno-ileal bypass creation using self-assembling IAS magnets was successful in all 8 pigs (100%). Patent, leak-free bypasses formed in all animals by day 10. All IAS magnets were expelled by day 12. Anastomoses were widely patent at 3months, with mean maximal diameter of 30mm. At necropsy, adhesions were minimal. Pressure testing confirmed superior integrity of anastomotic tissue. Histology showed full epithelialization across the anastomosis with no evidence of submucosal fibrosis or inflammation. Entero-enteral bypass using self-assembling IAS magnets is safe and technically feasible in the porcine model. IAS magnets can be rapidly delivered endoscopically or through a modified laparoscopic device. Expulsion of fused magnets avoids retention of prosthetic material. Anastomoses are widely patent and fully re-epithelialized. Three-month pressure testing reveals anastomotic tissue to be as robust as native tissue, while necropsy and histology suggests minimal/absent tissue inflammation. In human anatomy, a fully endoscopic jejuno-ileal bypass using IAS magnets may be feasible.

Endoscopic intestinal bypass creation by using self-assembling magnets in a porcine model

A purely endoluminal method of GI bypass would be desirable for the treatment of obstruction, obesity, or metabolic syndrome. We have developed a technology based on miniature self-assembling magnets that create large-caliber anastomoses (Incisionless Anastomosis System [IAS]). The aim of this study was to evaluate procedural characteristics of IAS deployment and long-term anastomotic integrity and patency. We performed a 3-month survival study of Yorkshire pigs (5 interventions, 3 controls). Intervention pigs underwent simultaneous enteroscopy/colonoscopy performed with the animals under intravenous sedation. The IAS magnets were deployed and coupled with reciprocal magnets under fluoroscopy. Every 3 to 6 days pigs underwent endoscopy until jejunocolonic anastomosis (dual-path bypass) creation and magnet expulsion. Necropsies and histological evaluation were performed. The primary endpoints were technical success; secondary endpoints of anastomosis integrity, patency, and histological characteristics were weight trends. Under intravenous sedation, endoscopic bypass creation by using IAS magnets was successfully performed in 5 of 5 pigs (100%). Given porcine anatomy, the easiest dual-path bypass to create was between the proximal jejunum and colon. The mean procedure time was 14.7 minutes. Patent, leak-free anastomoses formed by day 4. All IAS magnets were expelled by day 12. All anastomoses were fully patent at 3 months with a mean diameter of 3.5 cm. The mean 3-month weight was 45 kg in bypass pigs and 78 kg in controls (P = .01). At necropsy, adhesions were absent. Histology showed full re-epithelialization across the anastomosis without fibrosis or inflammation. Large-caliber, leak-free, foreign body-free endoscopic intestinal bypass by using IAS magnets can be safely and rapidly performed in the porcine by model using only intravenous sedation.

Abstract 199: Adipose-Derived Stem Cells from Diabetic Patients Undergo Endothelial Differentiation for Use in the Creation of a Tissue-Engineered Vascular Graft

INTRODUCTION: Surgical bypass and dialysis access creation are common procedures performed in diabetic patients. Only 55% of patients have autologous vascular tissue available for use as a conduit in these operations. We have developed an alternative conduit composed of a vascular scaffold seeded with autologous adipose-derived stem cells (ASC) differentiated into endothelial cells (EC) to create a non-thrombogenic lumen. OBJECTIVE: To examine ASC from diabetic (DM) versus non-diabetic (NDM) patients in terms of isolation efficiency, proliferation, commitment towards EC lineage, and seeding onto a vascular scaffold. METHODS: ASC were isolated from peri-umbilical liposuction specimens by collagenase dispersion (DM n=53; NDM n=145). Isolation efficiency was defined by number of ASC isolated per gram of adipose tissue. Proliferation was assessed by constructing growth curves over 14d. ASC were differentiated in endothelial growth medium for 3wk. Differentiation was determined by measuring EC-specific gene expression (CD31, vWF) using qPCR. Lastly, ASC were seeded onto decellularized vein, flow conditioned from 0-9 dynes over 5d, and examined using confocal microscopy. RESULTS: ASC isolation efficiency did not differ between DM and NDM patients (224,028 cells/gm vs. 259,345 cells/gm, respectively; P=0.21). The growth curves for DM (n=6) and NDM (n=6) ASC also appeared similar, with no significant differences observed in cells counts between days 1-14. After 1, 2, and 3wk in culture, no significant difference in CD31 or vWF expression between DM (n=6) and NDM (n=6) cells was observed. Finally, retention of ASC to vascular scaffolds under physiological shear stress was similar between the two groups. CONCLUSIONS: ASC are isolated from DM in quantities similar to those observed in NDM. These cells grow at rates similar to NDM ASC, exhibit differentiation into an EC phenotype, and line the lumen of a tissue engineered vascular graft. These results suggest that adipose tissue may prove to be a more reliable source of autologous stem cells than blood or bone marrow, where the presence of diabetes and other co-morbidities significantly decrease the availability of stem cells for use in regenerative therapies.

Bronchoskopische Lungenvolumenreduktion bei fortgeschrittenem Lungenemphysem: Zukunftsmusik oder viel Lärm um nichts?

Bronchoscopic lung volume reduction (BLVR) is a rapidly developing area and at present it is being intensively evaluated and discussed. There is a great interest in developing new treatment modalities that can reduce lung volume and air trapping without the risk of a surgical intervention. The different techniques of BLVR are characterised by lower morbidity and mortality, but by a more limited effect too. The placement of valves leads to blockade of the airway and sometimes to absorption atelectasis. The valves have been most intensively evaluated and are frequently applied. Beside the blocking devices there are partially blocking or deforming devices available as coils that are introduced in heterogeneous emphysema. Irreversible procedures such as polymeric lung volume reduction or thermal vapour ablation are used too. The creation of airway bypasses to allow trapped air to escape is mainly employed in homogenous emphysema. Following such by-pass creation there is an increase of lung function tests and a reduction of dyspnea, but only for a limited time. The bypass procedure has disappeared from bronchoscopy units completely. We give a review of the recent developments regarding BLVR and the state of the art.

ViPS (Viabahn Padova Sutureless) Technique: Preliminary Results in the Treatment of Peripheral Arterial Disease

To describe early results of a novel technique (ViPS, Viabahn Padova Sutureless) that connects a vascular prosthetic graft to a target artery in a sutureless fashion. A consecutive series of five patients with peripheral arterial occlusive disease (Rutherford class IV and V) underwent six ViPS procedures (one bilateral) for limb revascularization. Angiography in all cases demonstrated complete superficial femoral artery (SFA) occlusion with reconstitution of a circumferentially calcified above-knee popliteal artery. Ultrasonography revealed no adequate vein for autogenous bypass creation. In all cases,a previous attempt of SFA endovascular recanalization was unsuccessful. A Viabahn (W.L. Gore, Flagstaff, AZ) endoprosthesis was partially deployed, and its proximal end was sutured to a polytetrafluoroethylene graft. After surgical exposure, the circumferentially calcified popliteal artery, which could not be safely sutured, was transected and the undeployed distal portion of the Viabahn was inserted into the popliteal artery supported by a stiff guidewire. The distal portion of the Viabahn graft was then deployed 2.5 cm into the popliteal artery with optimal apposition. The proximal end of the polytetrafluoroethylene graft was then sutured to the common femoral artery. The distal portion of the Viabahn was ballooned to ensure apposition with the popliteal artery. The mean time for surgical modification of the device was 6.6 minutes with a mean time for ViPS anastomosis deployment of 7 seconds. Mean operative time for ViPS procedure was 61 minutes (range: 48-74). Completion angiogram in all cases demonstrated a patent graft with no sign of dissection. The patients' symptoms resolved in all cases, with complete ulcer healing occurring in five patients within 3 weeks. Follow-up imaging (mean = 2.6 months, range: 1-5) with eco-color-Doppler and computed tomography angiogram demonstrated a patent graft with no loss of device integrity in all cases. The ViPS technique is simple, easily performed, and provides an alternative for bypass creation, particularly in cases where challenging arterial anastomoses are required. Furthermore, this technique has the potential to reduce operative time and is accomplished using common commercially available devices.

ViPS technique as a novel concept for a sutureless vascular anastomosis

To describe a novel technique (Viabhan Padova Sutureless [ViPS]) that connects a vascular prosthetic graft to a target artery in a sutureless fashion. The patient was a 74-year-old male with complete superficial femoral artery (FA) occlusion and reconstitution of a circumferentially calcified above-knee popliteal artery (ANPA). The proximal end of a surgeon-modified 7-mm Viabahn endoprosthesis was sutured to a 7-mm polytetrafluoroethylene graft (PTFEg). After surgical exposure, the ANPA was transected, and the undeployed distal portion of the Viabahn was inserted, supported by a stiff guidewire. The distal portion of the Viabahn graft was then deployed and ballooned with optimal apposition. Finally, the proximal end of the PTFEg was sutured to the common FA. Operative time was 60 minutes. Completion angiogram and the computed tomography angiogram at 6 months demonstrated a patent graft. The ViPS technique provides an alternative for bypass creation when challenging arterial anastomoses are required.

Percutaneous bypass creation between hollow organs by modified gun-sight approach

This animal study investigated the feasibility of creating a bypass between two hollow organs, using a modified gun-sight approach with a pull-through string and pull-through tow wire. Ten procedures (femoral arteriovenous shunt, n = 4; portacaval shunt, n = 4; cholangiogastrostomy, n = 2) were performed in six adult swine. Snares were inserted into the two hollow organs through the sheath and deployed at the site of bypass creation. When snares overlapped on fluoroscopy, a needle was inserted to pass through both snares. The string was inserted through the needle, with only the needle then withdrawn. The snare furthest from the skin was closed to capture the string and was then withdrawn. The other snare was withdrawn without closing. The string thus served as a pull-through string penetrating both hollow organs. This string was then attached to a pull-through tow wire, withdrawn, and exchanged for the pull-through tow wire. By withdrawing the pull-through tow wire, the delivery sheath connected to the pull-through tow wire was towed through the site of the bypass, and the stent was placed. In all cases, bypass creation was achieved. Percutaneous bypass creation using a modified gun-sight approach with a pull-through string and pull-through tow wire is feasible between two hollow organs.

Femoral - internal iliac bypass in aortoiliac aneurysms endovascular repair.

The authors describe femoral - internal iliac bypass creation to remove ischemic complications in aortoiliac aneurysm endovascular repair. Based on a good experience with bypass in 6 patients they recommend its preventive indication when both internal iliac arteries are overstented.