Polytetrafluoroethylene Patch Research Articles

Subacute cardiac rupture: Repair with a sutureless technique

Thirteen patients with ages between 53 and 74 years had development of free wall left ventricular rupture after a myocardial infarction (mean interval, 3.8 days). All patients showed clinical signs of cardiac tamponade. Diagnosis was established by bedside multiple pressure monitoring and echocardiography, which showed pericardial effusion with compression of the right ventricle. Cardiac catheterization was not performed. A new surgical technique was employed for the repair. After the pericardium was opened and cardiac tamponade was relieved, the myocardial tear was identified. A Teflon patch was applied over the area and glued to the heart surface with a surgical glue (cyanoacrylate). Cardiopulmonary bypass was not used except in a patient with a posterior tear. The method was consistently effective in controlling bleeding from the myocardial tear. All patients survived the operation and were discharged from the hospital a mean of 15 days after the operation. Follow-up extending up to 5 years (mean, 26 months) shows a 100% survival, 11 asymptomatic patients, and 2 patients with mild exertional angina. The technique is a simple, effective, and safe method for repair of subacute cardiac rupture and obviates the need for suturing on an infarcted ventricle.

Hemodynamic Effects of Primary Closure Versus Patch Angioplasty of the Carotid Artery

This study evaluated the hemodynamic changes associated with patch angioplasty compared to primary closure of the canine carotid artery. A standard arteriotomy was closed either primarily, with a 5x28 mm expanded polytetrafluoroethylene (ePTFE) patch, or with a 10x28 mm ePTFE patch. Measurements for the primary closure group showed a systolic pressure gradient of 17 mmHg across the closure and a peak systolic velocity increase of 58% at mid-closure compared to proximal inflows. Flow turbulence increased at mid-closure in the 10 mm patch group, with the percent spectral window lowered from 0.50 to 0.36. These data show that primary vessel closure creates a mild local stenosis with flow acceleration but no flow turbulence. No significant hemodynamic disturbances are caused by a moderate sized patch; however, a large patch relative to native vessel dimensions creates marked flow disturbances throughout the cardiac cycle. As turbulence and flow separation are felt to contribute to restenosis, care should be taken in the selection of patch size when used following carotid endarterectomy.

Left main coronary trunk compression by dilated main pulmonary artery in atrial septal defect

Narrowing of the left main coronary trunk, which was compressed by the dilated pulmonary artery, was associated with atrial septal defect in three adults. One of them had severe pulmonary hypertension. Coronary angiograms revealed localized narrowing of the left main coronary trunk, and the left main coronary trunk had a concave shape. No stenosis of other coronary arteries was observed. In all patients the atrial septal defect was closed with a polytetrafluoroethylene patch. In the patient with 75% narrowing of the left main coronary trunk, aorta-coronary bypass was performed; it was not performed in the two with 50% narrowing. In two survivors postoperative coronary angiograms showed that the narrowing of the left main coronary trunk improved or disappeared. These results suggest that markedly dilated pulmonary arteries easily compress the left main coronary trunk and cause narrowing, which improves after atrial septal defect closure.

The use of polytetrafluoroethylene for particular augmentation of the nasal dorsum

In 24 cases scutiform polytetrafluoroethylene patches were implanted to correct saddle malformation and irregularities of the nasal dorsum. For smaller tissue defects of the nasal bone and cartilage, the patches are very suitable in rhinosurgery. One of the advantages of the implant is that it makes the reconstructed area appear as natural as possible.

Improved tissue ingrowth and anchorage of expanded polytetrafluoroethylene by perforation: an experimental study in the rat

Although an explaned polytetrafluoroethylene patch is a suitable synthetic material to repair large abdominal wall defects, lack of tissue ingrowth into the patch may give rise to herniation at the fasciapatch interface. This study was undertaken to determine whether perforations and/or ethanol pretreatment improved tissue ingrowth into the polytetrafluorethylene patch. Patches were implanted subcutaneously in 12 rats and evaluated 6 wk ( n = 4) or 12 wk ( n = 8) after implantation. Tissue ingrowth was only demonstrated into perforated patches. Stress-strain measurements showed that perforation caused a 25% decrease in the mechanical strength of the material. It was concluded that perforation might improve the anchorage of the polytetrafluoroethylene patch to the adjacent aponeurosis and thereby prevent herniation when the polytetrafluoroethylene soft tissue patch was used for the repair of abdominal wall defects.

The Effects of Shear Stress on Endothelial Cell Retention and Function on Expanded Polytetrafluoroethylene

We evaluated the adherence of indium 111-radiolabeled endothelial cells to fibronectin-treated expanded polytetrafluoroethylene surfaces exposed to high (437 s-1) vs low (218 s-1) shear and the influence of shear on prostacyclin production. Canine jugular vein factor VIII-positive endothelial cells in passages 3 through 6 were incubated with 111Indium-oxine, and labeled cells were seeded onto fibronectin-treated expanded polytetrafluoroethylene patches. Patches with confluent cells were exposed to shear in a Weissenberg rheogoniometer for intervals ranging up to 60 minutes. Percent endothelial cell retention was determined by gamma counting of patches and media and by histologic evaluation. Prostacyclin production (tritiated radioimmunoassay of 6-keto-prostaglandin F1 alpha) was assayed on perfusing media. Results showed no differences in 6-keto-prostaglandin F1 alpha production between shear rates or time periods. Endothelial cell retention did not differ between the shear rates. Rotational shear caused persistent cell loss over time in either high- or low-shear conditions. This persistent cell loss in response to steady rotational shear differs from that in response to identical rates of pulsatile linear shear in our laboratory where cell loss approached zero after 15 minutes.

Superior lumbar hernia associated with the lumbocostovertebral syndrome

A child with a superior lumbar hernia associated with the lumbocostovertebral syndrome is described. Congenital lumbar hernias are uncommon, with only 34 reported cases. Because of the difficulty of finding adequate tissue to repair these defects, we performed a prosthetic repair with a polytetrafluoroethylene (Gore-Tex) patch.

Carotid patch angioplasty: Immediate and long-term results

To determine the benefit of carotid patch angioplasty, a retrospective study of 1000 consecutive carotid endarterectomies was done. Based on the type of carotid endarterectomy closure, patients were divided into four groups: 250 had primary closure, 250 had expanded polytetrafluoroethylene patch, 250 had Dacron patch, and 250 had saphenous vein patch. On the basis of operative technique or type of carotid artery closure, no statistical difference was found in the incidence of postoperative stroke (p > 0.25): primary closure 1.6% (4), expanded polytetrafluoroethylene 2.0% (5), Dacron patch 1.6% (4), and saphenous vein patch (0). Postoperative carotid patency was determined by B-mode ultrasonography, and 717 patients were evaluated in follow-up extending to 6 years (mean 37.8 months). Based on the method of carotid endarterectomy closure, no significant difference (p > 0.25) was found in the incidence of significant restenosis (>50% diameter reduction): primary closure 4.0% (7), expanded polytetrafluoroethylene 4.0% (6), Dacron 5.4% (9), and saphenous vein 1.0% (2). Significant restenosis was most frequent in habitual smokers (93%, 2528) and females (78%, 2228) despite the method of carotid endarterectomy closure. No statistical difference was found in the incidence of late ipsilateral stroke either (p > 0.25): primary closure 2.9% (5), expanded polytetrafluoroethylene 2% (3), Dacron 5% (3), and saphenous vein 0%. These results indicate that the incidence of postoperative stroke, regardless of method of arterial closure, was not statistically different. The method of carotid closure did not appear to affect the occurrence of late ipsilateral stroke or restenosis; however, patch angioplasty with saphenous vein appears appropriate in habitual smokers, and likely in patients with small internal carotid arteries.

Autopsy finding 14 years after septation for single ventricle

The autopsy finding of a patient who survived 14 years after ventricular septation for single ventricle are reported. Although the patient had been well for years, she suddenly died at 22 years of age. Her ventricular free walls had grown normally, but the ventricular septum did not. A crevice was found in the apex, and the ventricular septum consisted of only the Teflon patch. Microscopically, fibrosis was found only in the right atrium.

Direct tricuspid closure versus atrial partitioning in Fontan operation for complex lesions

Thirty-three patients with complex lesions undergoing the Fontan operation needed either direct tricuspid closure (group 1, 14 patients) or atrial partitioning (group 2, 19 patients). In group 1, the tricuspid patch was sutured to the annulus leaving the coronary sinus draining to the systemic venous atrium. In group 2, atrial partitioning was accomplished with either a Dacron or a polytetrafluoroethylene patch, leaving the coronary sinus draining to the pulmonary venous atrium. Intraoperative distention of the left side was used to check for residual defects. In group 1, complete heart block developed in 5 patients (36%) and patch disruption, in 4 patients (29%). There were 3 late deaths (21%), which were due to sudden death, sepsis caused by Candida, and liver failure. In group 2, no patient had heart block, and patch disruption developed in 1 patient (5%). There was 1 early death (5%) and 2 late deaths (11%), which were due to sepsis caused by Candida and renal failure. Our experience suggests that atrial partitioning is a better approach than direct tricuspid patch closure in patients with complex lesions undergoing the Fontan operation.

Comparison of saphenous vein patch, polytetrafluoroethylene patch, and direct arteriotomy closure after carotid endarterectomy. Part I. Perioperative results

To evaluate the perioperative outcomes and the immediate increases in size after patch closure, 140 carotid endarterectomies were randomized into one of three groups: direct no-patch closure, saphenous vein patch closure, and polytetrafluoroethylene patch closure. Seven patients (4.4%) experienced signs of cerebral ischemia in the immediate postoperative period. In three cases this was transient and reversible. In the other four reexploration was undertaken and carotid thrombosis was corrected by thrombectomy. The condition of one of these patients deteriorated to a permanent stroke, whereas the other patients made a complete recovery. Neurologic complications were more frequent in the no-patch group, but the differences between the groups were not significant. The incidence of perioperative internal carotid stenosis, aneurysmal dilatation, and other morphologic abnormalities was assessed in 131 intravenous digital subtraction angiograms taken before the patient was discharged from the hospital. Eight (17.0%) of the endarterectomies in the no-patch group were narrowed by 30% to 50% diameter stenosis, whereas none of the patched arteries had more than 30% stenosis. In contrast, dilatation of the common or internal carotid artery to more than twice the measured diameter was absent in nonpatched arteries but was present in seven (17.0%) saphenous patch closures and four (9.23%) polytetrafluoroethylene patch closures. We conclude that patch closure after carotid endarterectomy is less likely to cause stenosis in the perioperative period. Polytetrafluoroethylene patches resist dilatation better than do saphenous vein patches and are less likely to become aneurysmal.

Comparison of saphenous vein patch, polytetrafluoroethylene patch, and direct arteriotomy closure after carotid endarterectomy. Part I. Perioperative results

Comparison of saphenous vein patch, polytetrafluoroethylene patch, and direct arteriotomy closure after carotid endarterectomy. Part I. Perioperative results

Biomechanical evaluation of rotator cuff fixation methods.

Initial fixation strength and failure mode for various rotator cuff reattachment techniques (variations of the McLaughlin technique) were evaluated. Repair methods included standard suture (control), reinforced suture [expanded polytetrafluoroethylene (PTFE) patch and polydioxanone (PDS) tape augmentation] and stapling (nonarthroscopic and arthroscopic soft-tissue staples). The average strength of intact rotator cuff tissue (supraspinatus tendon) was also determined. The different rotator cuff repairs, including at least one control, were performed on fresh-frozen human cadaver shoulder pairs. Repairs were tested to failure in pure tension with the shoulder fixed in 60 degrees of abduction. Load and displacement data were normalized to controls, grouped according to failure modes, and statistically analyzed. The two basic failure modes observed were 1) bone failure, or suture tearing through the bone (indicating weak bone stock) and 2) tendon failure, or suture tearing of the rotator cuff. Gross comparisons between intact and repaired tendons indicated that the intact tendon was two to three times stronger than the repaired tendon. Based on the mode of failure and lack of increased strength after repair, the use of staples for cuff attachment is discouraged. PDS tape suture reinforcement did not increase fixation strength. In contrast, PTFE patch suture augmentation demonstrated statistically higher initial failure loads than did the control and was of specific benefit for shoulders with weak bone stock.

Prosthetic reconstruction of the trachea

Tracheal reconstruction has been a difficult and challenging problem over the years, mainly because of graft infection and extrusion. A small segment of the trachea can be resected and primary anastomosis can be performed easily with satisfactory results. The problem is always complex when a substantial portion of the trachea must be resected. A variety of prosthetic materials have been used, both in experimental animals and human subjects, with limited short-term success. This study describes an experiment using polytetrafluoroethylene (PTFE) grafts in dogs. PTFE patch and interposition grafts were used for tracheal reconstruction with very satisfactory results. Inflammatory reaction near the grafts and nonincorporation of long graft segments continue to be problems, but despite this, prosthetic reconstruction of the trachea using PTFE provided very satisfactory results in our experimental study.

Adhesion formation and peritoneal healing on prosthetic materials

Abdominal wall defects were repaired in 75 Sprague-Dawley rats with either Marlex mesh (25 rats), expanded polytetrafluoroethylene (PTFE) patch or polyglycolic acid (PGA) mesh (25 rats). Adhesion formation and peritoneal healing on these materials were serially investigated from one to 22 weeks after implantation. Adhesions to expanded PTFE were significantly less dense than to either Marlex or PGA mesh ( p<0.05). A further 30 rats underwent abdominal wall repair with Marlex mesh (15 rats) or expanded PTFE patch (15 rats) in the presence of a staphylococcus aureus wound infection. One week after implantation, adhesions to expanded PTFE patch were significantly less than to Marlex mesh ( p<0.05), but thereafter maximum adhesions were seen on both materials. Peritoneal healing was complete on expanded PTFE patch, but was scanty on Marlex and PGE meshes and was inhibited in the presence of a wound infection.

Repair of Large Abdominal Wall Defects with Expanded Polytetrafluoroethylene (PTFE)

Most abdominal wall incisional hernias can be repaired by primary closure. However, where the defect is large or there is tension on the closure, the use of a prosthetic material is indicated. Expanded polytetrafluoroethylene (PTFE) patches were used to repair incisional hernias in 28 patients between November 1983 and December 1986. Twelve of these patients (43%) had a prior failure of a primary repair. Reherniation occurred in three patients (10.7%). Wound infections developed in two patients (7.1%), both of whom had existing intestinal stomas, one with an intercurrent pelvic abscess. The prosthetic patch was removed in the patient with the abscess, but the infection was resolved in the other without sequelae. Septic complications did not occur after any operations performed in uncontaminated fields. None of the patients exhibited any undue discomfort, wound pain, erythema, or induration. Complications related to adhesions, erosion of the patch material into the viscera, bowel obstruction, or fistula formation did not occur. Based on this clinical experience, the authors believe that the PTFE patch appears to represent an advance in synthetic abdominal wall substitutes.

Pathogenesis of aneurysm formation opposite prosthetic patches used for coarctation repair: An experimental study

Patch graft angioplasty for coarctation repair has been associated with late aneurysm formation opposite the prosthetic patch in some patients. Etiologic possibilities for this aneurysm formation include congenital abnormality of the aortic wall, surgical interruption of the vasa vasorum, intimal disruption because of extensive excision of the coarctation web, and rigidity of the prosthetic patch. To assess the effect of extensive intimal excision on the development of aneurysms, we operated on 12 dogs, performing a left thoracotomy and aortoplasty with Dacron (n = 6) or polytetrafluoroethylene patches (n = 6) and concomitant intimal excision opposite the patch. Ten control dogs underwent angioplasty with Dacron (n = 5) and polytetrafluoroethylene patches (n = 5) without excision of the intima. Serial aortograms of all animals showed aneurysm formation of the aorta opposite the patch in eight of the 12 dogs undergoing intimal excision. In contrast, no aneurysms developed in the control dogs (p less than 0.001). An additional five dogs underwent longitudinal aortotomy, intimal excision, and primary closure. Three dogs in this group demonstrated an aneurysm angiographically (p less than 0.02). Histologic analysis of the aneurysms and the control aortas revealed hyperplastic ingrowth of the intima over the denuded surface in the animals undergoing intimal excision. The elastic fibers in the media were intact and organized except in two aneurysmal specimens. We conclude that extensive resection of the intima with or without patch angioplasty predisposes aneurysm formation opposite the aortotomy and should be avoided during coarctation repair.

Surgical management of post–myocardial infarction ventricular tachyarrhythmia by myocardial debulking, septal isolation, and myocardial revascularization

Sustained ventricular tachycardia or ventricular fibrillation, associated with severely depressed left ventricular function after myocardial infarction, carries a poor prognosis. We have used an extensive surgical procedure in 18 patients (15 men and three women) with a mean age of 63 years who had more than three episodes of recurrent, hemodynamically significant ventricular tachycardia or fibrillation and congestive heart failure. The operation consisted of complete myocardial revascularization and myocardial debulking by extensive infarctectomy with unguided endocardial resection and septal isolation with support of the necrotic wall with a Teflon patch. Implantable defibrillator patches were placed in eight patients. Blood cardioplegia and intra-aortic balloon assist (12 patients) were used for perioperative myocardial preservation. Postoperative studies demonstrated a significant increase in ejection fraction (n = 16) and a decline in pulmonary wedge pressure. Hospital mortality was 16% (three patients). Two deaths were due to congestive heart failure and one to arrhythmia. During postoperative electrophysiologic studies, ventricular tachycardia was not inducible in six of eight patients (75%). During a mean follow-up of 24 months, 11 of 15 patients who survived operation are alive and are in New York Heart Association Class I or II. Three of four late deaths were due to congestive heart failure and drug toxicity and one was arrhythmia related. This procedure is effective for preventing recurrent ventricular tachycardia or fibrillation in a majority of patients who cannot have intraoperative mapping.

“Tire Patch” Angioplasty: A New Method of Arterial Repair

A method of controlling a problematic aortotomy suture line using an onlay patch of polytetrafluoroethylene (Gore-Tex) is described. This method has been used successfully in several instances with good control of bleeding and no complications.

Staged surgical treatment of early bacterial endocarditis after surgical repair of tetralogy of Fallot and discrete subaortic stenosis: Report of a case

An unconventional method of managing infection of the interventricular Teflon patch in a patient with tetralogy of Fallot is reported. The patch was initially replaced by a new patch. After reinfection, however, removal of the patch and pulmonary banding eradicated the infection, and at a later stage the defect was re-repaired successfully.