Polytetrafluoroethylene Prosthesis Research Articles

Three-Dimensional Morphological Study on the Effectiveness of Expanded Polytetrafluoroethylene Prosthesis in the Paranasal Augmentation.

The paranasal depression is a common facial feature of Oriental populations. One of the most wildly used method to improve it was paranasal augmentation using expanded polytetrafluoroethylene (ePTFE). The effectiveness of it should be tested by three-dimensional morphological measurements. Patients who underwent paranasal augmentation using ePTFE between January 2017 and December 2022 were recruited in the study. The preoperative and postoperative clinical variables and three-dimensional measurement of patients were also collected. The satisfaction outcome were assessed. By establishing a coordinate system based on the Frankfurt plane, 16 landmarks including nasal alar crest, subnasal point, upper lip, pogonion, glabella, sub-cheek, orbitale, tragion in left and right side of faces were marked. Five segments, 4 ratios, and 3 angles were measured based on it. The significant increase of segments, ratios, and angles indicated that paranasal augmentation could increase the protrusion of paranasal area, both in absolute value and relative proportion. The significant decrease of other data indicated that the protrusion difference between paranasal base and upper lip, forehead, and chin, respectively, were shortened after surgery. The average size of implant was 6.54 ± 1.02mm, and the average increase of paranasal height was 4.38 ± 1.04mm postoperatively. This indicates that two-thirds of its height will ultimately be reflected effectively in the sagittal elevation of the paranasal base. Paranasal augmentation using ePTFE could effectively increase paranasal height and improve subunits relationships, and the ePTFE prosthesis should be designed and carve considering the 1/3 loss of height after implantation. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A clinical case of surgical treatment of a child with aneurysms of the abdominal aorta and aortic bifurcation, superior mesenteric artery and multiple aneurysms of the main arteries

A brief literature review on abdominal aortic aneurysms in children and our own observation of surgical treatment of a 5-year-old child with an aneurysm of the abdominal aorta and aortic bifurcation, an aneurysm of the superior mesenteric artery, and multiple aneurysms of the arteries of the lower extremities has been presented in the paper. Staged replacement of the aortic aneurysm and superior mesenteric artery with synthetic polytetrafluoroethylene prostheses was performed. The features of surgical interventions, difficulties and complications that the authors encountered during the treatment of the child are described.

Encasement Of Popliteal Vascular Bundle Due Local Osteosarcoma Recurrence Treated With Wide Resection And Vascular Reconstruction.

Osteosarcoma is the most common primary bone malignancy. The prognosis of patients after local recurrence is generally poor and management of the locally recurrent disease is not well defined, especially in patients who have undergone limb-sparing surgery. A 20-year-old male presented a local recurrence of conventional osteosarcoma at the popliteal fossa with encasement of popliteal vascular bundle after previous tumor-wide resection and reconstruction with proximal tibia endoprosthesis. A wide resection "en bloc" of the lesion included part of the popliteal vessel. A bypass of both popliteal vessels, the vein with polytetrafluoroethylene (PTFE) prosthesis, and the artery with contralateral saphenous vein were performed to allow a limb salvage surgery. Local management of recurrent osteosarcoma in a previously reconstructed limb is highly individualized. This case confirms that preservation of lower limb function is possible using reconstruction techniques of bone and vessels in the sarcoma of the musculoskeletal system.

A study of outcome of ossiculoplasty using autologous cartilage, refashioned incus, and polytetrafluoroethylene (Teflon) prosthesis in patients of chronic suppurative otitis media

AimTo find out the mean air conduction thresholds (ACT) and air–bone gap (ABG) closure across the treatment groups at the end of 3 and 6 months of follow-up.Material and methodsSixty patients diagnosed with COM with conductive hearing loss were included in the study. Air conduction threshold (ACT) and air–bone gap were calculated and recorded pre-operatively. Surgery was done with clearance of disease followed by reconstruction of hearing in single-stage operation using autologous conchal cartilage, refashioned incus, and polytetrafluoroethylene (Teflon) prosthesis (PORP, TORP) depending upon the intraoperative findings during surgery. Patients were followed for up to 6 months for assessing the hearing outcome in terms of the mean air conduction threshold and mean air–bone gap closure for each group separately.ResultsThe outcome of each ossiculoplasty material was calculated in terms of mean air conduction threshold and mean AB gap closure. Preoperative and postoperative air conduction threshold (ACT) at 3 months and 6 months follow-up of each group was as follows: for the autologous conchal cartilage group, 41.3 (± SD 6.69), 29.2 (± SD 5.39), and 21 (± SD 4.66); for autologous refashioned incus group, 40.4 (± SD 5.43), 28.4 (± SD 6.73), and 20.8 (± SD 4.33); for the Teflon PORP group, 42.9 (± SD 5.68), 31.4 (± SD 6.86), and 34.9 (± SD 6.37); and for the Teflon TORP group, 43.1 (± SD 5.40), 32.5 (± SD 5.91), and 36.2 (± SD 5.31). The mean air–bone gap preoperatively and postoperatively at 3 months and 6 months respectively were as follows: for autologous conchal cartilage, 40.6 (± SD 4.57), 23.7 (± SD 4.48), and 20 (± SD 5.28); for autologous refashioned incus, 39.3(± SD 4.92), 21.9 (± SD 5.61), and 19.4 (± SD 5.82); for Teflon PORP 43.0 (± SD 4.48), 32.8 (± SD 4.84), and 36.3 (± SD 5.56); and for Teflon TORP, 44.5 (± SD 5.56), 33.2 (± SD 5.53), and 35.2 (± SD 5.10).ConclusionThe hearing outcome of ossiculoplasty varies with the type of ossiculoplasty material used. Most favorable results were obtained with refashioned autologous incus followed by autologous conchal cartilage. Teflon prosthesis has a significant improvement in hearing outcomes although the results are less favorable.

Anterior and posterior tracheopexy for severe tracheomalacia.

Congenital tracheomalacia can be the cause of respiratory failure in young children. Although the indication for surgical treatment has already been discussed vigorously, no clear guidelines about the modality are available. Through a sternotomy approach, a combination of posterior pexy and anterior tracheopexy using a tailored ringed polytetrafluoroethylene prosthesis is performed. Patient demographic characteristics, as well as operative details and postoperative outcomes, are included in the analysis. Between 2018 and 2022, 9 children underwent the operation under review. All patients showed severe clinical symptoms of tracheomalacia, which was confirmed on bronchoscopy. The median age was 9months. There was no operative mortality. Eight patients could be weaned from the ventilator. One patient died because of interstitial lung disease with bronchomalacia and concomitant severe cardiac disease. The longest follow-up now is 4years, and shows overall excellent clinical results, without any reintervention. Surgical treatment of tracheomalacia through a combination of posterior and anterior pexy is feasible, with acceptable short- and midterm results.

Treatment for cephalic arch stenosis with cephalic vein to external jugular vein bridging graft.

Percutaneous transluminal angioplasty or cephalic vein transposition to the axillary vein is mainly used for treatment of cephalic arch stenosis, a common complication of brachiocephalic fistulas. However, the results of such interventions have been disappointing. We used a polytetrafluoroethylene prosthesis with a 6 mm diameter to bridge the cephalic vein and the ipsilateral external jugular vein, and successfully created a new drainage outlet and established immediate restoration of flow through brachiocephalic fistulas. This surgery allowed the cephalic venous arch and subclavian vein, which are vulnerable to stenosis, to be bypassed altogether and the puncture segment could be elongated by about 20 cm. It is a safe and effective alternative to traditional methods of treatment for cephalic arche stenosis.

Swine Models of Aneurysmal Diseases for Training and Research.

Large animal models, specifically swine, are widely used to research cardiovascular diseases and therapies, as well as for training purposes. This paper describes two different aneurysmal swine models that may help researchers to study new therapies for aneurysmal diseases. These aneurysmal models are created by surgically adding a pouch of tissue to carotid arteries in swine. When the model is used for research, the pouch must be autologous; for training purposes, a synthetic pouch suffices. First, the right external jugular vein (EJV) and right common carotid artery (CCA) must be surgically exposed. The EJV is ligated and a vein pouch fashioned from a short segment. This pouch is then sutured to an elliptical arteriotomy performed in the CCA. Animals must be kept heparinized during model creation, and local vasodilators may be used to decrease vasospasms. Once the suture is completed, correct blood flow should be inspected, checking for bleeding from the suture line and vessel patency. Finally, the surgical incision is closed by layers and an angiography performed to image the aneurysmal model. A simplification of this aneurysmal carotid model that decreases invasiveness and surgical time is the use of a synthetic, rather than venous, pouch. For this purpose, a pouch is tailored in advance with a segment of a polytetrafluoroethylene (PTFE) prosthesis, one end of which is sutured close using polypropylene vascular suture and sterilized prior to surgery. This "sac" is then attached to an arteriotomy performed in the CCA as described. Although these models do not reproduce many of the physiopathological events related to aneurysm formation, they are hemodynamically similar to the situation found in the clinical setting. Therefore, they can be used for research or training purposes, allowing physicians to learn and practice different endovascular techniques in animal models that are close to the human system.

Treatment of Gut Haemorrhage by Superior Vena Cava Reconstruction in Behçet’s Disease

A 35 year old man with Behçet’s disease, on warfarin, was treated for significant repeated haematemesis. Additional investigations revealed downhill, grade III upper oesophageal varices, without portal hypertension, caused by superior vena cava (SVC) thrombosis and development of a large bypassing azygos vein. He was treated by replacing the fibrotic SVC with a polytetrafluoroethylene prosthesis (20 mm; W.L. Gore and Associates, Flagstaff, AZ, USA) via sternotomy (A). Ligation of the azygos vein was performed after well tolerated clamping of the right atrium. (B) At 24 months post-operatively, a computed tomography angiogram confirmed graft patency (arrow) without recurrence of oesophageal varices.Image 1

Primary stapedotomy: Influence of prosthesis diameter on hearing outcome

ObjectivesTo evaluate the success rate of primary stapedotomy and to investigate the influence of prosthesis diameter on hearing outcome. Material and methodsRetrospective medical chart review of 125 cases who underwent primary small fenestra stapedotomy, from January 2001 to December 2018. The study population was divided in two groups based on Teflon prosthesis diameter – .6mm (60%, N=75) and .4mm (40%, N=50). Pre- and postoperative (≥12 months) air-conduction (AC), bone conduction (BC) and air-bone gap (ABG) thresholds were compared. ResultsPostoperative ABG≤10dB and ≤20dB was achieved by 65.7% and 90% of the patients. A functional hearing (PTA-AC≤30dB) was achieved by 59.2% of patients. Sensorineural hearing loss (SNHL, worsening in BC-PTA>10dB) was identified in 7.2% of patients. Comparison of the .6mm- and .4mm-groups, revealed no differences regarding improvements in AC-PTA (22.4 vs. 20.7dB, p=.56), BC-PTA (3.4 vs. 2.3dB, p=.54) and ABG-PTA (19.1 vs. 18.4dB, p=.77). Hearing outcome evaluation identified similar postoperative success rate (.6mm, 79.7% vs. .4mm, 62%, p=.336) and comparable functional hearing (.6mm, 64% vs. .4mm, 52%; p=.197). The incidence of postoperative SNHL was similar between the two pistons (.6m, 5.3% vs. .4mm, 10%, p=.481). ConclusionPrimary small fenestra stapedotomy is an effective and safe procedure. A postoperative ABG within 10dB was achieved in 67.2% of patients and there was a reduced incidence of sensorineural hearing loss. Hearing outcome was not influenced by diameter of the selected prosthesis. Postoperative bone conduction hearing thresholds did not differ between the groups, which revealed no significant inner ear trauma caused by the larger piston. Although we did not find evidence to suggest one piston over the other, our results showed a trend toward better results with the larger prosthesis.

Comparative study between Teflon and Robinson stainless steel Prostheses in ototsclerosis surgery

BACKGROUND: The main cause of conductive hearing loss in the presence of a completely normal tympanic membrane is otosclerosis. There are different types of prostheses that could be used in the operation with different materials, designs, and shapes. The prostheses utilized in this study including both Teflon and Robinson are assessed. The aim of our work is to match and determine the surgical steps, postoperative results, and surgical complications of both Teflon piston and Robinson titanium prosthesis in line with the improvement in hearing and therefore the ability to decrease the air-bone gap.Results: stapedotomy done for 40 patients with Teflon piston and Robinson stainless steel piston prosthesis, 20 patients for each type. Both groups were matched based on age and preoperative bone-conduction scores. Follow up for all patients were done up to 6 months postoperatively. We have excluded all revision cases. A comparison between both prostheses was assessed by differences in the Air Bone (AB) Gap and surgical difficulties and complications. Both groups showed no significant difference either in hearing improvement or postoperative decrease of an air-bone gap. The Robison titanium piston needs more surgical skills than Teflon one. Both groups had no surgical complications.Conclusions: There is an equal benefit to patients with the use either of Teflon piston or Robinson protheses and there is no statistically significant difference between both of them. We need a long time of follow up the results to be analyzed.Keywords: Teflon prosthesis, Robinson prostheses, otosclerosis, stapedectomy.

Hydroxyapatite Prostheses in Endoscopic Transcanal Stapes Surgery for Otosclerosis Cases.

Hydroxyapatite is a commonly used material for medical applications due to its excellent biocompatibility. We use hydroxyapatite prosthesis for the reconstruction of the ossicular chain in stapes surgery. In this study, we report a case series of endoscopic ear surgery using a basket-type hydroxyapatite prosthesis. We retrospectively examined 8 cases of endoscopic transcanal stapes surgery using hydroxyapatite prostheses. We evaluated the postoperative results and complications. The average postoperative air-bone gaps were within 10 dB in all cases. Postoperative sensorineural hearing loss was not observed in any case. There was an intraoperative complication with the chorda tympani in 1 patient. We were able to preserve the chorda tympani of all patients, including this case. Postoperative transient dizziness and transient taste disorder were observed in 50% of cases. No other complications, including facial nerve palsy, tympanic membrane perforation, or postoperative infection, were observed. The postoperative results and complications were comparable to those of surgery under a microscope. The hydroxyapatite prosthesis could be a possible alternative for the piston-type titanium or polytetrafluoroethylene prosthesis.

Safety of limb-salvaging surgery for sarcomas compromising major vessels: A 15-year single-centre outcomes study.

Limb-threatening sarcomas invading major vessels present an oncological and reconstructive challenge. Curative resection involves either performing an amputation or an immediate reconstruction of the invaded vessels. We present our 15-year experience of these cases at the North of England Bone and Soft Tissue Tumour Service. A Strengthening the Reporting of Observational studies in Epidemiology (STROBE) compliant retrospective review of our prospective database was performed including patients who required major vessel reconstruction following sarcoma excision from 2003 until 2018. Patient demographic data along with tumour and histological subtypes, treatment modality, complications and outcomes were inquired. Autologous and prosthetic vessel reconstruction approaches were compared. Nineteen patients were identified with the most common tumour locations being the thigh and groin areas. Five cases involved recurrent tumours. Clear resection margins were obtained in 15 cases. Autologous vein grafts were preferred over polytetrafluoroethylene (PTFE) prosthesis in 17 cases. A pedicled flap or free flap was required to achieve adequate soft tissue cover in six patients, while the rest underwent primary closure. Five patients lost the patency of the reconstructed vessels with one of these requiring an amputation. The estimated disease-specific survival at 5 years was 58%. Limb-preservation surgery in the context of vessel compromise is not only safe, but also a functionally and psychosocially beneficial means of avoiding an amputation. We believe that careful pre-operative planning and discussion in a multidisciplinary setting is key for obtaining positive outcomes.

Hearing Outcome in Ossiculoplasty With Autologous Incus and Teflon Prosthesis in Chronic Otitis Media: a Comparative Study.

To observe and compare the functional outcome in term of hearing gain in ossiculoplasty with autologous incus and Teflon made TORP/PORP in cases of chronic otitis media (COM) with ossicular disruption. 60 patients of COM between age of 11-50years who had ossicular disruption were included in the study. They were divided into two groups of 30 patients/ group: group 1 included those patients who had mucosal COM and group 2 included those who had squamous COM. They were further subdivided into 3 subgroups each as per the ossiculoplasty material used. Pre-operative pure tone audiometry (PTA) was done. They all were followed-up at 3months after surgery and at that time PTA was done. Pre-and post-operative hearing was compared and hearing improvement was calculated in term of air-bone gap (ABG). Out of 60 cases, 16 cases marked as failure of ossicular reconstruction as post-operative A-B gap was > 30dB. Among these 16 cases, 7 were those patients whom ossiculoplasty was done using autologous incus and in rest 9 patients PORP/TORP was used. Success rate of ossiculoplasty using refashioned incus was 76.66% whereas Teflon TORP/PORP had success rate of 70.00%. We conclude that hearing improvement after ossiculoplasty with autologous incus is better as compare with that obtained by Teflon TORP/PORP. Also, it is a cost-effective method.

Primary stapedotomy: Influence of prosthesis diameter on hearing outcome

ObjectivesTo evaluate the success rate of primary stapedotomy and to investigate the influence of prosthesis diameter on hearing outcome. Material and methodsRetrospective medical chart review of 125 cases who underwent primary small fenestra stapedotomy, from January 2001 to December 2018. The study population was divided in two groups based on Teflon prosthesis diameter – .6mm (60%, N=75) and .4mm (40%, N=50). Pre- and postoperative (≥12 months) air-conduction (AC), bone conduction (BC) and air-bone gap (ABG) thresholds were compared. ResultsPostoperative ABG≤10dB and ≤20dB was achieved by 65.7% and 90% of the patients. A functional hearing (PTA-AC≤30dB) was achieved by 59.2% of patients. Sensorineural hearing loss (SNHL, worsening in BC-PTA>10dB) was identified in 7.2% of patients. Comparison of the .6mm- and .4mm-groups, revealed no differences regarding improvements in AC-PTA (22.4 vs. 20.7dB, p=.56), BC-PTA (3.4 vs. 2.3dB, p=.54) and ABG-PTA (19.1 vs. 18.4dB, p=.77). Hearing outcome evaluation identified similar postoperative success rate (.6mm, 79.7% vs. .4mm, 62%, p=.336) and comparable functional hearing (.6mm, 64% vs. .4mm, 52%; p=.197). The incidence of postoperative SNHL was similar between the two pistons (.6m, 5.3% vs. .4mm, 10%, p=.481). ConclusionPrimary small fenestra stapedotomy is an effective and safe procedure. A postoperative ABG within 10dB was achieved in 67.2% of patients and there was a reduced incidence of sensorineural hearing loss. Hearing outcome was not influenced by diameter of the selected prosthesis. Postoperative bone conduction hearing thresholds did not differ between the groups, which revealed no significant inner ear trauma caused by the larger piston. Although we did not find evidence to suggest one piston over the other, our results showed a trend toward better results with the larger prosthesis.

Long-term results of polytetrafluoroethylene versus saphenous vein repair of degenerative carotid artery aneurysm

ObjectiveTo compare the results of polytetrafluoroethylene (PTFE) and great saphenous vein (GSV) bypass after resection of a degenerative aneurysm of the carotid artery. MethodsFrom January 1994 to November 2017, 37 patients (27 men) with a mean age of 58 years (range, 39-82 years) with a degenerative aneurysm of the carotid artery (median diameter, 28 mm; range, 19-42 mm), underwent resection of the aneurysm followed by a bypass with either a GSV (n = 10) or a PTFE prosthesis (n = 27). Although 31 patients were asymptomatic, 6 patients were symptomatic: transient ischemic attack (n = 4), minor stroke (n = 1), and compression of the hypoglossal nerve (n = 1). The preoperative workup included duplex ultrasound examination of the arteries to the head, and angiography or computed tomography angiography. All patients were operated under general anesthesia and six were intubated through the nose. Sixteen patients were monitored through transcutaneous oximetry. No shunt was used in this series. In 10 patients receiving a PTFE graft, the external carotid artery was implanted in the prosthesis. Mean follow-up was 16.9 ± 2 years (95% confidence interval, 14.5-19.3 years). Primary end points were the 30-day combined stroke/death rate, graft infection, late graft patency, and late stroke-free survival. Secondary end points were cranial nerve injury and length of postoperative hospital stay. ResultsPostoperative mortality was nil in both groups. One postoperative stroke was observed in the PTFE group, whereas none occurred in the GSV group (P = .84). No graft infection was observed in either group. At 10 years, survival in the GSV group was 80 ± 12%, and survival in the PTFE group was 76 ± 8% (log-rank [Mantel-Cox], P = .85). In the GSV group, graft patency at 7 and 10 years was 85 ± 13%. In the PTFE group B, graft patency was 100% (log-rank [Mantel-Cox], P = .12). No late stroke was observed. Two transient cranial nerve injuries were observed in the GSV group (20%) and two in the PTFE group (8%) (P = .97). Length of hospital stay was comparable in both groups (GSV group, 6 days; PTFE group, 5 days; P = .12). ConclusionsThis study suggests that, after resection of a degenerative aneurysm of the carotid artery, bypass with a PTFE prosthesis gives comparable results to those obtained with the GSV. We recommend sparing the GSV and instead using a PTFE prosthesis in patients with a degenerative aneurysm of the carotid artery.

Outcomes of type III tympanoplasty: our experience

<p class="abstract"><strong>Background:</strong> Type III tympanoplasty involves complete disease clearance from middle ear cleft and retaining or improving the serviceable hearing by ossiculoplasty. Various auto and allografts have been used with variable outcomes. The objective of the study was to evaluate hearing improvement and healing of cavity in patients who underwent type III tympanoplasty.</p><p class="abstract"><strong>Methods:</strong> A retrospective chart review of 21 patients who underwent type III tympanoplasty at Bowring and Lady Curzon Hospital from January 2018 to December 2018 was done. In 7 patients autologous incus, 6 tragal cartilage and 8 teflon prosthesis was used for ossiculoplasty. Intra and postoperative events were assessed. Pure tone audiograms done after 3 and 6 months were compared. </p><p class="abstract"><strong>Results:</strong> 15 patients who underwent canal wall down procedure (CWDP) had a mean hearing gain of 20.33 dB and 26.67 dB while in 5 patients of canal wall up procedure (CWUP) group mean hearing gain was 22.5 dB and 27.5 dB at 3 and 6 months after surgery respectively. Hearing gain was similar in both groups irrespective of the prosthesis used. Autologous materials were used in most of the CWUP with intact stapes and teflon prosthesis was used in majority of CWDP where only mobile stapes foot plate was present. Prosthesis extrusion was not encountered in any of our cases so far in this series.</p><p class="abstract"><strong>Conclusions:</strong> The post-operative hearing gain with autologous incus, tragal cartilage and teflon middle ear prosthesis are similar. Teflon prosthesis is an effective material for ossiculoplasty, especially useful when incus and stapes are absent while autologous incus or tragal cartilage are preferred in cases with intact stapes head.</p>

Teflon implants vs titanium implants in stapedotomy - A comparative study

Objective: This study compares two types of implants- a Teflon piston and a titanium piston, used in stapes surgery for otosclerosis. Study Design: A non-randomised prospective study conducted on 40 patients, in 2 groups of 20 each, undergoing stapedotomy in a tertiary care hospital. Pure tone audiometry results were noted preoperatively and 3 weeks post-operatively.Results: Both Teflon and titanium prostheses provided almost equal benefits to patients in terms of Air-Bone gap closure.Conclusion: While there is statistically no significant difference in the results observed, surgical skill of the operating surgeon plays an important role in hearing improvement and long-term results would require long term evaluation.

Creation of Arteriovenous Fistulas and Grafts Concomitantly with Endovascular Correction of Outflow Veins: A Hybrid Procedure

Achieving well-functioning dialysis fistulas is a common problem in dialyzed patients, and it is mainly caused by the pathologies of vessels used for fistula creation. Hybrid therapies, combining surgical and endovascular procedures, potentially enable the creation of functional dialysis fistulas in patients with vessels that are otherwise unsuitable for vascular access. Between January 1, 2014 and June 30, 2018, we created dialysis fistulas simultaneously with endovascular correction of outflow pathologies in 15 patients. The included patients had a long history of dialysis (median 10.5years, range 3-22) and many previous dialysis access procedures (mean 5.3 procedures, range 2-9). In 13 patients (86.7%), the fistula was created on the upper arm; in 5 patients (33.3%), it was arteriovenous graft done with polytetrafluoroethylene (PTFE) prosthesis (in an additional 3 patients, a PTFE prosthesis was used to extend the vein), and 7 patients had native vessel fistulas (46.7%). Endovascular procedures, in some cases performed on more than 1 vein, were applied for correction of the subclavian vein (8 patients, 53.3%); brachiocephalic vein (6 patients, 40.0%); cephalic, basilic, and axillary veins (2 patients each, 13.3%); and superior cava vein (1 patient, 6.7%). Access for the endovascular procedure was achieved through a dissected vein used for arteriovenous anastomosis. The fistula function was monitored, and all complications of dialysis access were noted. The median follow-up in the observed group was 18months. We compared the patency of dialysis fistula creation combined with endovascular correction of outflow vein pathology to our results of standard dialysis fistula operations: radiocephalic dialysis fistula creation (RCAVF group, 65 patients) and dialysis fistula stenosis angioplasty (PTA group, 30 patients). The 12- and 24-month primary patency rates of dialysis fistulas created in hybrid procedures with simultaneous outflow vein pathology correction were 72.7% and 63.6%, respectively. No early complications related to endovascular or open procedures were observed. A hybrid procedure for the creation of a dialysis fistula with the simultaneous correction of outflow pathologies enables a properly functioning dialysis fistula to be obtained. This procedure can be performed in patients with complicated vascular situations, enabling the creation of dialysis fistulas. Our results of hybrid procedures, involving simultaneous endovascular correction of the outflow vein with dialysis fistula creation, showed the efficiency and good results.

Reaction of connective tissue of arterial and venous walls to implantation of synthetic and biological grafts

30% of patients in the remote period appear to develop restenosis of the anastomoses formed during reconstructive-restorative operations on vessels. Two major causes of restenosis have been determined: intimal hyperplasia and smooth muscle cell proliferation. The reaction of connective-tissue elements of vascular walls in response to implantation of grafts remains unstudied. The study was undertaken to examine the reaction of connective tissue of the arterial and venous walls to implantation of synthetic and biological grafts. We analysed the results of an experimental study performed on a total of 60 rabbits divided into 4 groups each consisting of 15 animals: in the first 2 groups we examined tissue reaction to implantation of synthetic and biological grafts on the wall of an artery and in the remaining 2 groups - on the wall of a vein. The synthetic grafts were made of polytetrafluoroethylene, with the biological ones made of bovine internal thoracic arteries. The portions of the vessels along with the implanted grafts were subjected to histological examination on postoperative days 14, 21 and 30. The specimens were studied by means of light microscopy after haematoxylin-eosin staining. We also carried out a morphometric study consisting in determining the quantitative ratio of the cellular composition of connective tissue. After implantation on the arterial wall, the connective-tissue capsule under the synthetic prosthesis was 1.8 times thicker than under the biological one, with predominance of the cellular component over fibrous one, which deformed the zone of implantation. Under the biological prosthesis, the capsule on the arterial wall was presented by fibrous structures with no deformation of the zone of implantation. The reparative reaction of the venous wall to implantation of the synthetic prosthesis was represented by a thin fibrous connective-tissue capsule. The reaction of the venous wall to the biological transplant was at all terms of the experiment characterised by significant inflammatory alterations with granulomatosis and immunomorphological shifts with formation of lymphoid follicles on the border with the transplant. Implantation of the synthetic polytetrafluoroethylene prosthesis on the arterial wall induced a hyperplastic reaction of the elements of connective tissue, and a normoplasic one on the venous wall. Implantation of the biological prosthesis on the arterial wall did not induce proliferation of connective-tissue elements, and on the venous wall - granulomatous inflammation.

Aortic aneurysm: A life-threatening condition in a low-resource nation

Background: Aortic aneurysm is said to be uncommon in the black population; however, with the modification in lifestyle of the dark-skinned people, and improved diagnostic facilities in Sub-Saharan African nations, a surge in its presentation is more likely. If undiagnosed, aortic aneurysm can be catastrophic. We determined the epidemiology pattern and outcome of aortic aneurysm at our institution. Materials and Methods: This is a retrospective analysis of patients who presented with aortic aneurysm from 2000 to 2017. A pro forma was designed to analyze the bio data, characteristics of the aneurysms, clinical manifestation, treatment, and outcome. The Crawford, Stanford, and DeBakey criteria were used to classify the aortic aneurysm. The surgical management of the aneurysm was resection and its replacement with synthetic polytetrafluoroethylene prosthesis with antibiotic prophylaxis under general anesthesia. Results: A total of 17 patients were recruited, with a mean age of 62.75 ± 20.92 years. A high proportion were above 65 years, i.e., 7 (41.2%), and male gender, i.e., 10 (58.8%). The most common location of aortic aneurysm using Crawford criteria was Type IV followed by Type I, with Stanford criteria being Stanford Type B (13) and with DeBakey being Type III (3). Five operated were fusiform in shape. A higher proportion of patients, i.e., 14 (82.4%), had coexisting hypertension, and a positive history of smoking, i.e., 7 (41.2%). The 30-day mortality was 64.7%, the operative mortality was 35.3%, and three patients (17.6%) were loss to follow-up. A positive history of smoking increased the risk of dead, relative risk 3.375, 95% confidence interval 0.677–5.909, P = 0.04. Conclusion: Aortic aneurysm, though uncommon, is not a rare disease among cardiovascular disorders in a low-resource environment. The most common shape and location were fusiform and Stanford Type B or DeBakey Type III, respectively. There was associated high 30-day mortality (64.7%).