Tubular Prosthesis Research Articles

A RARE CASE OF LOEYS–DIETZ SYNDROME: THE IMPORTANCE OF DIAGNOSIS IN PATIENTS UNDERGOING CARDIOVASCULAR SURGERY

Abstract Background Loeys–Dietz syndrome (LDS) is a rare autosomal dominant genetic disorder of connective tissue, characterised by a broad spectrum of craniofacial, vascular (arterial tortuosity and aneurysms) and skeletal clinical signs. Four subtypes have been described, related to mutations in genes encoding for components of the transforming growth factor beta signalling pathway (TGFBR1, TGFBR2, SMAD2, SMAD3, TGFB2 and TGFB3). Diagnosis is based on the evaluation of clinical manifestations and family history. Therefore, many radiologists remain unfamiliar with the imaging and clinical findings in LDS. The Case 75–year–old woman, history of surgery for ruptured gastric a. aneurysm and ectasia of visceral arterial vessels. One year onset of worsening dyspnoea and asthenia, at echocardiography (ECOCG) severe aortic insufficiency has been detected and patient underwent aortic valve replacement with bioprosthesis. Cardiac surgery was complicated by aortic dissection (Stanford A; DeBakey I type) treated with replacement of ascending aorta and anterior hemiarch with tubular prosthesis. On that occasion a family diagnosis of SMAD3 gene mutation was made (both sister and nephew typed), compatible with Loeys–Dietz syndrome type 3. At the control angioTC evidence of proximal and distal anastomosis in order, in the absence of signs of periprosthetic leak. At ECOCG (FE 55%), thickened septum with marked postcardiac dyskinesia. No abnormality detected on ECG. Due to persistence of dyspnoea on mild exertion (NYHA class III) and reduced tolerance to orthostatism, cardiac rehabilitation program was undertaken on an outpatient basis for three months, providing an improvement in exertion tolerance (NYHA II) and a benefit on functional autonomy. LDS is a multisystem connective tissue disorder that is associated with a high burden of complications, a correct diagnosis will allow clinicians to appropriately establish the best therapeutic strategy, especially in cardiac surgery, taking into account the intraoperative and perioperative potential risks.

A Giant Left Common Iliac Artery Aneurysm with Endovascular Repair: A Case Report

Common iliac artery aneurysm (CIAA) is a very rare entity, but with potentially disastrous evolution, aneurysm rupture or distal embolization. A specific management, surgical or endovascular procedure, is required. We present a case with a huge distal left common iliac artery aneurysm, in which the diagnosis was made incidentally during a weekly ultrasound examination, in spite of impressive dimensions, 9 cm diameter. The patient was then examined by 128- Slices computed tomography and angio-coronarography. Despite the attractive anatomy for direct surgery with resection of the aneurysm and restoration of the iliac tract through the interposition of a tubular prosthesis, due to the previous pathology of the patient with necrotizing fasciitis in the left lower limb and abdominal wall, endovascular intervention was decided. Because, the big size of the left common iliac artery aneurysm, located distally, with tortuosity of the left common iliac artery as well external iliac artery (EIA), permeable left internal iliac artery (IIA), extensive intra-aneurysmal thrombosis, endovascular procedure was complex and particular. The peculiarities of the case and the complex endovascular technique, with the placement of a stent graft on the infrarenal abdominal aorta, extended on both common iliac arteries, embolization of the left internal iliac artery and extension of the left arm on the external iliac artery, are described in this presentation.

495 STANFORD TYPE-A ACUTE AORTIC DISSECTION: A LIFE-THREATENING EMERGENCY

Abstract Stanford type A acute aortic dissection is a life-threatening cardiological emergency which occurs when an intimal tear in the ascending aorta creates a false lumen within the media refilled by pulsatile blood flow. Some investigators report the immediate mortality to be as high as 40%. Both congenital and acquired conditions can be the cause of an instability of the aortic wall that can lead to dissection. Diagnosis, which requires a high level of suspicion, is usually made with aortic angio-CT. The case we present involves a 62-years old man with a history of hypertension, parossistic atrial fibrillation and familiarity for type B aortic dissection. He called 911 complaining of sudden onset dorsal pain that then irradiated anteriorly to the chest and upwardly to the neck, associated with profuse sweating. An EKG performed at patient's home showed ST elevation in V1 meaningful of right ventricle infarction. Arrived at the Emergency Ward of our hospital arterial pressure was 80/50 mmHg with an HR of 44 bpm. Rapidly, because of the suspect of aortic dissection, an angio-TC was performed showing a type A aortic dissection starting from Valsalva sinuses and extending till common right iliac artery and external left iliac artery including left subclavian artery ostium. The left renal artery originated from false lumen, but patient had a so-called horseshoe kidney. For this reason, the patient was transferred immediately to the cardiac surgery room with indication for Bentall procedure (aortic valve plus ascending aorta replacement with home-made valved Dacron tubular prosthesis), aortic arch repair with supra-aortic vessels debranching and reimplantation and saphenous graft on right coronary artery. During surgery was evident that intimal tear was located immediately after left common carotid artery and right coronary sinus was involved in the dissection thus explaining why right ventricle free wall was visibly hypokinetic. Surgery went without complication and patient entered ICU with circulation supported by a low dose of epinephrine and norepinephrine; respiratory weaning took place in day 1 post-operation. The following days patient developed circumferential pericardial effusion which needed percutaneous subxiphoid drainage despite not being hemodynamically relevant. Echocardiography before discharge showed aortic valve prosthesis and ascending aorta prosthesis well positioned, bi-ventricular normal dimensions and function and organized residual pericardial effusion with fibrin strands. Stanford type A is the most common type of aortic dissection and requires immediate surgical treatment. The Bentall procedure is considered the gold standard for patients needing ascending aorta plus aortic valve replacement. Even though mortality rates remain high for Stanford type A acute aortic dissection, this case shows how is possible to survive from such a life-threatening condition if a prompt and correct diagnosis is made and thanks to flawless surgical operation.

TNF-mimetic peptide mixed with fibrin glue improves peripheral nerve regeneration

Surgical intervention is necessary following nerve trauma. Tubular prostheses can guide growing axons and inserting substances within these prostheses can be positive for the regeneration, making it an alternative for the current standard tools for nerve repair. Our aim was to investigate the effects of fibrin glue BthTL when combined with a synthetic TNF mimetic-action peptide on nerve regeneration. Male Wistar rats suffered left sciatic nerve transection. For repairing, we used empty silicon tubes (n = 10), tubes filled with fibrin glue BthTL (Tube + Glue group, n = 10) or tubes filled with fibrin glue BThTL mixed with TNF mimetic peptide (Tube + Glue + Pep group, n = 10). Animals were euthanized after 45 days. We collected nerves to perform immunostaining (neurofilament, GAP43, S100-β, NGFRp75 and Iba-1), light and transmission electron microscopy (for counting myelinated, unmyelinated and degenerated fibers; and for the evaluation of morphometric aspects of regenerated fibers) and collagen staining. All procedures were approved by local ethics committee (protocol 063/17). Tube + Glue + Pep group showed intense inflammatory infiltrate, higher Iba-1 expression, increased immunostaining for NGFRp75 receptor (which characterizes Schwann cell regenerative phenotype), higher myelin thickness and fiber diameter and more type III collagen deposition. Tube + Glue group showed intermediate results between empty tube and Tube + Glue + Pep groups for anti-NGFRp75 immunostaining, inflammation and collagen; on fiber counts, this group showed more degenerate fibers and fewer unmyelinated axons than others. Empty tube group showed superiority only in GAP43 immunostaining. A combination of BthTL glue and TNF mimetic peptide induced greater axonal regrowth and remyelination.

Intermediate-Term Outcomes After Aortic Valve Replacement With the Medtronic 3F Stentless Prosthesis

This study evaluated the early and intermediate-term clinical and hemodynamic results after implant of the Medtronic 3F (Minneapolis, MN) stentless aortic valve. Between March 2007 and August 2015, 226 consecutive patients affected by aortic valve disease received a 3F valve at our unit by a single surgeon. The valve in 30 patients was included in a tubular prosthesis for a Bentall procedure. Size ranged between 21 and 29, age at operation was 74.17 ± 8.58 years, mean logistic European System for Cardiac Operative Risk Evaluation was 9.73 ± 6.00, and 51.3% of patients received a concomitant procedure. For isolated valve replacement, mean extracorporeal circulation time was 92 ± 17 minutes, and cross-clamp time was 73 ± 11 minutes. Follow-up was 100% complete and was a mean of 63 ± 2.4 months (range, 6-138 months). Primary end points were early and late mortality, freedom from endocarditis, freedom from structural valve deterioration, and freedom from valve-related reoperation. Early mortality after isolated aortic valve replacement was 1.7%. Of the 59 (25.3%) late overall deaths, 15 (6.6%) were cardiac-related, and survival rate was 93% at 10 years. At follow-up, 97% of patients were in New York Heart Association class I or II. Actuarial freedom from reoperation due to structural deterioration was 100% at 5 years and 96% at 10 years. Freedom from endocarditis at 10 years was 97%. Mean aortic pressure gradient measured by echocardiography was 11.5 mm Hgat hospital discharge and 10.4 mm Hg at the last follow-up. The 3F valve is a user-friendly third-generation stentless aortic prosthesis with proven durability and remarkable hemodynamic performance preserved over time. The 3F is particularly useful in cases of expected patient/prosthesis mismatch.

Matching Static and Dynamic Compliance of Small‐Diameter Arteries, with Poly(lactide‐co‐caprolactone) Copolymers: In Vitro and In Vivo Studies

Mechanical mismatch between vascular grafts and blood vessels is a major cause of smaller diameter vascular graft failure. To minimize this mismatch, several poly-l-lactide-co-ε-caprolactone (PLC) copolymers are evaluated as candidate materials to fabricate a small diameter graft. Using these materials, tubular prostheses of 4 mm inner diameter are fabricated by dip-coating. In vitro static and dynamic compliance tests are conducted, using custom-built apparatus featuring a closed flow system with water at 37 °C. Grafts of PLC monomer ratio of 50:50 are the most compliant (1.56% ± 0.31∙mm Hg-2 ), close to that of porcine aortic branch arteries (1.56% ± 0.43∙mm Hg-2 ), but underwent high continuous dilatation (87 µm min-1 ). Better matching is achieved by optimizing the thickness of a tubular conduit made from 70:30 PLC grafts. In vivo implantation and function of a PLC 70:30 conduit of 150 µm wall-thickness (WT) are tested as a rabbit aorta bypass. An implanted 150 µm WT PLC 70:30 prosthesis is observed over 3 h. The recorded angiogram shows continuous blood flow, no aneurysmal dilatation, leaks, or acute thrombosis during the in vivo test, indicating the potential for clinical applications.

Surgical Treatment Methods of Post-coarctation Aneurysms of Aorta

Introduction. Aortal coarctation is one of the most studied conditions of heart congenital defects, which comprises from 7% to 10% of all congenital heart defects.
 During many years the various treatment strategies were used. Open surgical reconstructive intervention was first de-scribed in 1945, and this was, as a rule, resection of aortal narrowed portion.
 Although the treatment of coarctation is usually successful in a short-term perspective, there is a well-known fact of de-velopment of complications at the later stages, especially after surgical reconstruction, such as post-coarctation aneurysms.
 Objective. To analyze surgical methods of correction of coarctation.
 Materials and methods.in the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine during the period 1960–2017, 4245 patients were operated with native coarctation of aorta.
 Selective patients’ choice for this work was restricted only by such cases of aneurysm of descending aorta, for which the data were reliable. Considering the above, we will be limited by the period of observation, starting from 1995.
 Totally, 91 cases with aneurysm of descending aorta were included in this work, 85 (93.4%) of patients were re-operated, 6 (6.6%) of patients were not operated due to various reasons. The patient distribution by age and gender at the moment of correction of aortal coarctation showed that they included 68 (74.7%) males and 23 (25.3%) females in the ratio 2.9:1. The average patient age by that time was 14.7, ranging from 1 to 38 years.
 By the moment of discovery of post-coarctation aneurysm the patients’ age increased to an average 38.1, ranging from 21 to 60 years. The average time interval between the surgery of aortal coarctation and diagnosis of aneurysm of descending aorta was 22 years, ranging from 1 month to 45 years.
 The frequency of complications of aneurysm of descending aorta after surgery of aortal coarctation was different for various surgical methods. Among the aneurysms, which developed after coarctation correction, the most frequent were aneurysms after implantation of synthetic patch – 61(88.5%). The less frequent were aneurysms in 6 (8.7%) patients after implantation of tubular prostheses, and in 2 (2.8%) patients – after end-to-end anastomosis.
 Results and discussion. Till recent time the standard treatment practice was open surgical operation with direct access to proximal part of descending aorta by left-sided lateral.
 In our Department 85 surgical interventions were performed, including 69 surgeries by the traditional surgical method. From these patients, 7(10.1%) were operated two times, and 2(2.9%) – three times. In all 69(81.2%) cases, operated by open traditional surgical method, we performed vascular prosthesis implantation.
 Such operations require highly qualified anesthetic support with obligatory differential endobronchial intubation, cor-rection of disorders of respiratory and kidney functions, and compensation of present and possible blood loss [4]. Consider-ing high probability of uncontrolled hemorrhage at the stage of aneurysm mobilization, we installed temporary bypass graft – 75.3% or CPB pump – 24.7%, from ascending aorta or left atrium to descending aorta or femoral artery.
 Hospital mortality in this patient cohort was 5.9%.The use of endovascular treatment of thoracic aorta aneurysm increased considerably since Dake et al. in 1994 implanted the first stent-graft into thoracic aorta.
 In our Department, we performed 16(18.8%) of the procedures under general anesthesia with spinal drainage. For the patients, who require the covering of the zone of going of left subclavian artery or left common carotid artery, we perform extra-anatomic shunting 9(10.5%), or even subtotal debranching 2(0.2%), if there is no possibility to use individually pre-pared scalped stent-graft. The most common access is through common femoral artery by operative access 15(17.6%), or, more recently, by transcutaneous access 1(1.1%).

Right aortic arch with an aberrant left subclavian artery and aortic coarctation including a descending aortic aneurysm

BackroundThe right aortic arch and aortic coarctation are rare congenital anomalies with the incidence of 0.1% and 0.03–0.04%. We present a case report of a 51-year-old woman with the right aortic arch with aberrant left subclavian artery and coarctation of the aorta with post-stenotic aneurysm.Case presentationResection of the coarctation and aneurysm with replacement by tubular prosthesis was performed on partial cardiopulmonary bypass via femoral vessels.ConclusionPartial cardiopulmonary bypass is an applicable method for ensuring the perfusion of the distal part of the body and an aberrant left subclavian artery is not a contraindication of this technique.

Aortic flow after valve sparing root replacement with or without neosinuses reconstruction

ObjectivesThis study applied advanced 4-dimensional flow magnetic resonance imaging processing to assess differences in aortic flow dynamics after valve sparing root replacement, with and without reconstruction of the Valsalva sinuses. MethodsWe enrolled patients after valve sparing root replacement with a straight tubular prosthesis (n = 10) or with a prosthesis with Valsalva neosinuses (n = 10); age-matched subjects without cardiovascular diseases served as controls (n = 10). 4-Dimensional flow magnetic resonance imaging acquisitions were performed on a 3.0T magnetic resonance imaging unit. In-house processing was used to segment the aortic lumen and extract the volumetric 4-dimensional flow velocity field. Velocity flow streamlines were computed to compare the amount of rotational flow and wall shear stress. Occurrence of abnormal wall shear stress (WSS) was estimated within the descending aorta of each surgical group. ResultsPhysiologic-like sinus vortices were visible in the aortic root when using the prosthesis with neosinuses, whereas straight tubular graft revealed localized intrados malrotations (P = .003 for organized vortical structures vs neosinuses graft and P < .001 vs control). In the ascending aorta, recreation of the sinuses resulted in significantly lower velocity and WSS than in the straight tubular graft (P < .001) and controls (P < .001), these alterations were attenuated in the mid-descending aorta. Incidence of abnormal WSS was markedly higher in the straight tube grafts than neosinus of Valsalva grafts. ConclusionsRe-creation of the sinuses of Valsalva during valve-sparing root replacement is associated with more physiologic flow and significantly lower WSS in the aortic root. Lower WSSs in the distal thoracic aorta is a novel finding with potential implications on distal aortic remodeling.

Sciatic nerve repair using poly(ε-caprolactone) tubular prosthesis associated with nanoparticles of carbon and graphene.

IntroductionInjuries to peripheral nerves generate disconnection between spinal neurons and the target organ. Due to retraction of the nerve stumps, end‐to‐end neurorrhaphy is usually unfeasible. In such cases, autologous grafts are widely used, nonetheless with some disadvantages, such as mismatching of donor nerve dimensions and formation of painful neuromas at the donor area. Tubulization, using bioresorbable polymers, can potentially replace nerve grafting, although improvements are still necessary. Among promising bioresorbable synthetic polymers, poly(l‐lactic acid) (PLLA) and poly(ε‐caprolactone) (PCL) are the most studied. Carbon nanotubes and graphene sheets have been proposed, however, as adjuvants to improve mechanical and regenerative properties of tubular prostheses. Thus, the present work evaluated nerve tubulization repair following association of PCL with nanoparticles of carbon (NPC) and graphene (NPG).MethodsFor that, adult Lewis rats were subjected to unilateral sciatic nerve tubulization and allowed to survive for up to 8 and 12 weeks postsurgery.ResultsNanocomposites mechanical/chemical evaluation showed that nanoparticles do not alter PCL crystallinity, yet providing reinforcement of polymer matrix. Thus, there was a decrease in the enthalpy of melting when the mixture of PCL + NPC + NPG was used. Nanocomposites displayed positive changes in molecular mobility in the amorphous phase of the polymer. Also, the loss modulus (E”) and the glass transition exhibited highest values for PCL + NPC + NPG. Scanning electron microscopy analysis revealed that PCL + NPC + NPG prostheses showed improved cell adhesion as compared to PCL alone. Surgical procedures with PCL + NPC + NPG were facilitated due to improved flexibility of the prosthesis, resulting in better stump positioning accuracy. In turn, a twofold increased number of myelinated axons was found in such repaired nerves. Consistent with that, target muscle atrophy protection has been observed.ConclusionOverall, the present data show that nanocomposite PCL tubes facilitate nerve repair and result in a better regenerative outcome, what may, in turn, represent a new alternative to pure PCL or PLLA prostheses.

Pseudoaneurysm with Fistula in Metal Aortic Prosthesis and Tubular Prosthesis in Ascending Aorta:Contribution of 3D Echocardiography

Pseudoaneurysm with Fistula in Metal Aortic Prosthesis and Tubular Prosthesis in Ascending Aorta:Contribution of 3D Echocardiography

Echocardiographic diagnosis of acute aortic syndrome in the emergency department

An 82-year-old woman was admitted to our emergency department in hemodynamically stable condition, 12h after the beginning of severe retrosternal chest pain of 1h duration, not influenced by changes in body position, nor aggravated by breathing and no more repeated. The ECG showed a typical pattern of acute pericarditis with diffuse concave upward ST-segment elevation >1 mm. Cardiac troponin levels, 12h after chest pain, were in the normal range, excluding the diagnosis of acute coronary syndrome. Chest X-ray displayed significant mediastinal enlargement. Transthoracic echocardiography documented mild anterior pericardial effusion (10 mm) and severe aneurysmal dilatation of the ascending aorta (antero-posterior diameter of 7 cm, measured 5 cm above the aortic valve plane) with significant wall thickening and no evidence of intimal flap. In addition, both left and right ventricles showed normal morphology and systolic function; pulmonary artery systolic pressure was 28 mmHg. Transesophageal echocardiography confirmed the significant dilatation of the ascending aorta, with a typical pattern of aortic penetrating ulcer (observed 5 cm above the aortic valve plane) associated with an intramural hematoma of the anterior wall, extended from the level of the sino-tubular junction to 9 cm above the aortic valve plane (acute aortic syndrome, Svensson type II). A diagnosis of acute aortic syndrome was made and, considering the risk for acute aortic dissection or aortic rupture, the patient was quickly transferred to the nearest Cardiac Surgery Center. Computed tomography confirmed the echocardiographic findings and the patient underwent replacement of the ascending aorta with a tubular prosthesis. The present case underlines the great utility of portable echocardiography in the emergency department, for the clinical evaluation of patients with different patterns of chest pain and, particularly, in the differential diagnosis of acute aortic syndromes.

A new concentric double prosthesis for sutureless, magnetic-assisted aortic arch inclusion

Acute dissection of the ascending aorta is a life-threatening condition in which the aortic wall develops one or more tears of the intima associated with intramural rupture of the media layer with subsequent formation of a two lumina vessel. The remaining outer layer is just the adventitia, with high risk of complete rupture. Vital organs may be under-perfused. Mortality rate in this acute event is about 50% if an emergent surgical procedure is not performed as soon as possible to replace the tract affected by the primary rupture. Nevertheless, the emergent surgical procedure is affected by high risk of mortality or severe neurologic sequelae, due to the need for deep hypothermia and cardiocirculatory arrest and different methods of cerebral protection. If the patient survives the acute event, a frequent outcome is the establishment of a chronic aortic dissection in the remaining aorta and late chronic dissecting aneurysm, usually starting from the surgical suture itself. Traumatism of surgical stitches and of direct blood flow pressure on weak aortic wall can be important contributing factors of the chronic disease. In conclusions, the majority of these patients undergoes a high risk operation without a complete solution of the disease.We hypothesize that excluding the aortic layers from the blood direct flow and using an anastomotic technique which does not include surgical stitches could help to significantly reduce the recurrence of aortic dissection after the acute event and shorten hypothermic arrest duration. We devised a double tubular prosthesis consisting of two concentric artificial tubes between which the aortic wall is confined and excluded from direct blood flow. We also devised a magnetic assisted sutureless anastomotic technique that seals the aortic tissue between the two prostheses and avoids the perforation of the fragile aortic wall with surgical stitches. We are presenting here this new prototype and draw a few different models. Both acute and chronic diseases of the aorta could benefit from the proposed technique, although acute dissection is the ideal scenario for its use.

Mesenchymal stem cells engrafted in a fibrin scaffold stimulate Schwann cell reactivity and axonal regeneration following sciatic nerve tubulization.

The present study investigated the effectiveness of mesenchymal stem cells (MSCs) associated with a fibrin scaffold (FS) for the peripheral regenerative process after nerve tubulization. Adult female Lewis rats received a unilateral sciatic nerve transection followed by repair with a polycaprolactone (PCL)-based tubular prosthesis. Sixty days after injury, the regenerated nerves were studied by immunohistochemistry. Anti-p75NTR immunostaining was used to investigate the reactivity of the MSCs. Basal labeling, which was upregulated during the regenerative process, was detected in uninjured nerves and was significantly greater in the MSC-treated group. The presence of GFP-positive MSCs was detected in the nerves, indicating the long term survival of such cells. Moreover, there was co-localization between MSCs and BNDF immunoreactivity, showing a possible mechanism by which MSCs improve the reactivity of SCs. Myelinated axon counting and morphometric analyses showed that MSC engrafting led to a higher degree of fiber compaction combined with a trend of increased myelin sheath thickness, when compared with other groups. The functional result of MSC engrafting was that the animals showed higher motor function recovery at the seventh and eighth week after lesion. The findings herein show that MSC+FS therapy improves the nerve regeneration process by positively modulating the reactivity of SCs.

Biocompatible heterogeneous porous gel matrix NeuroGel(TM) promotes regeneration of rat sciatic nerve within tubular silicone prosthesis (experimental study).

The purpose of this study was to investigate the ability of NeuroGel™ to promote and enhance the regeneration of rat sciatic nerve within a 10-mm gap using silicone tubular prosthesis, and to evaluate and compare the regeneration outcomes versus autologous grafting. The 10-mm gap of rat sciatic nerve was bridged through silicone tubular prosthesis filled with dehydrated NeuroGel™, and NeuroGel™ saturated with rat NGF-B (NG30-NGG60, NGgfB30-NGgfB60). To assess the regeneration of the peripheral nerve we utilized three general and most commonly applied methods: electrophysiologic, hystomorphometric, and functional methods. The average M-wave amplitude (AMW index), or the intermediary index of the number of regenerated axons, in animal groups NGG60 and NGgfB60 60 days post-op was: 2.44 ± 0.57 mV and 1.87 ± 0.48 mV. These indices were statistically lower compared to the indices obtained after autologous grafting. The average impulse conduction velocity along motor fibers (VMF index), or the intermediary index of myelination rate, was: 13.3 mm/ms and 13.3 mm/ms, respectively, statistically equal to indices obtained after autologous grafting. The average density (D) of regenerated fibers (direct numerical indicator in contrast to intermediary AMW index) in animal groups NGG60 and NGgfB60 was: 4,920 ± 178.88 and 5,340 ± 150.33 per mm(2), respectively. These indices were statistically higher versus indices obtained after autologous grafting. Myelination rates of regenerated fibers in animal groups NGG60 and NGgfB60 were 73 and 86 %, respectively. They were also statistically higher. The average sciatic functional index (SFI) in NGG60 and NGgfB60 was: -25.57 ± 3.05 and -24.124 ± 4.8, respectively, which is statistically equal to indices obtained after autologous grafting. Neurogel™ strongly promotes the regeneration of rat sciatic nerve within silicone tubular prosthesis. After bridging a 10-mm gap through silicone prosthesis with Neurogel™ or Neurogel™ +NGF-B-modified intraluminal space, the myelination rate of regenerated axons of rat sciatic nerve appeared to be higher, and the axon count and functional recovery is similar to results seen with the autografting technique.

Enhanced peripheral nerve regeneration by the combination of a polycaprolactone tubular prosthesis and a scaffold of collagen with supramolecular organization

The purpose of this study was to investigate the influence of implanting collagen with a supramolecular organization on peripheral nerve regeneration, using the sciatic nerve tubulization technique. For this purpose, adult female Sprague Dawley rats were divided into five groups: (1) TP – sciatic nerve repaired with empty polyethylene tubular prothesis (n = 10), (2) TPCL – nerve repair with empty polycaprolactone (PCL) tubing (n = 8), (3) TPCLF – repair with PCL tubing filled with an implant of collagen with a supramolecular organization (n = 10), (4) AG – animals that received a peripheral nerve autograft (n = 8), and (5) Normal nerves (n = 8). The results were assessed by quantification of the regenerated fibers, nerve morphometry, and transmission electron microscopy, 60 days after surgery. Immunohistochemistry and polarization microscopy were also used to analyze the regenerated nerve structure and cellular elements. The results showed that the AG group presented a larger number of regenerated axons. However, the TPCL and TPCLF groups presented more compact regenerated fibers with a morphometric profile closer to normal, both at the tube midpoint and 2 mm distal to the prosthesis. These findings were reinforced by polarization microscopy, which indicated a better collagen/axons suprastructural organization in the TPCLF derived samples. In addition, the immunohistochemical results obtained using the antibody anti-p75NTR as a Schwann cell reactivity marker demonstrated that the Schwann cells were more reactive during the regenerative process in the TPCLF group as compared to the TPCL group and the normal sciatic nerve. Altogether, the results of this study indicated that the implant of collagen with a supramolecular organization positively influenced and stimulated the regeneration process through the nerve gap, resulting in the formation of a better morphologically arranged tissue.

What Is the Optimum Cover Factor?

When fabricating a small diameter arterial prosthesis, the performance requirements include controlling dimensions, maintaining a uniform structure, ensuring superior mechanical properties as well as excellent biocompatibility. Material selection and fabricating methods can influence these factors. In this study, three 100% polyester prostheses, three bicomponent polyester/silk prostheses and three 100% silk prostheses were woven into seamless tubular prototype prostheses with three different basic weaves. After degumming/scouring they met the target inner diameter of 3.83 ± 0.30 mm which demonstrates that weaving is a precise and accurate way to manufacture small caliber arterial prostheses. In conclusion, the woven samples had a uniform wall structure along their strength and a range of low water permeability values and probe bursting strengths depending on their cover factor.

Extended replacement of a calcified ascending aorta in adulthood sporadic, diffuse type, supravalvular aortic stenosis

The diffuse variant of supravalvular aortic stenosis (SVAS) is one of the most rare congenital vascular pathological conditions of adulthood. Due to its rarity, surgical treatment of this clinical entity is still a matter of debate because of the variable degree of aortic narrowing, presence of multilevel obstruction, and age at presentation, all factors that strongly influence the disease prognosis. We report a case of an adult patient with an extremely calcified diffuse SVAS who underwent successful replacement of the ascending aorta through the interposition of a tubular prosthesis. Six months' follow-up showed complete relief of the aortic gradient and an improvement in clinical performance.

Alternative Approach for Endovascular Treatment of Aortic Aneurysms

Endovascular treatment of thoracic aortic aneurysms is limited in patients with small or calcified femoral arteries, with the most serious complication being rupture at the insertion site or distal sections of the artery. To overcome this, an iliac conduit is normally created by surgical exposure. We used an original access in a patient with a thoracoabdominal aortic aneurysm and narrow femoral artery to introduce the endovascular prosthesis directly into the surgically exposed iliac artery by a small laparotomy and abdominal wall tunnel without iliac conduit. The endoprosthesis was easily implanted, and complete hemostasis was achieved with minimal blood loss.

Aortoesophageal fistula, a catastrophic complication soon after successful repair of an aortic dissection type A

A 66-year-old man with a history of arterial hypertension underwent emergency cardiac surgery for aortic dissection type A, diagnosed by a computed tomographic scan ( Panel A ) after abdominal pain and syncope. The lesion was repaired with a Dacron tubular prosthesis. In the postoperative period, he improved his condition slowly under mechanical …