Double polytetrafluoroethylene patch repair for diaphragmatic defect caused by diaphragmatic rupture following diaphragmatic resection with endostapler.

A 41-year-old man developed phrenic nerve palsy after the resection of anterior mediastinal tumor, who underwent diaphragmatic resection with an endostapler. After the surgery, the surgical stump ruptured, resulting in a large diaphragmatic defect with the liver prolapsing into the thoracic cavity. Then, the diaphragmatic defect was closed with a polytetrafluoroethylene (PTFE) patch. The diaphragm was reconstructed using a second PTFE patch overlaying the diaphragmatic defect that had been closed by the first PTFE patch, because solely patching the diaphragmatic defect had a risk of recurrence of diaphragmatic elevation due to remaining original diaphragm and the presence of phrenic nerve palsy. The second PTFE patch was fixed to the lower ribs by non-absorbable suture. The postoperative course was favorable. After 3 months, his symptoms and pulmonary function improved. We underwent double PTFE patch repair in a patient with both huge diaphragmatic defect and phrenic nerve palsy.

A Comparison of Two Arthroscopic Techniques for Interpositional Polytetrafluoroethylene Patch Repair for Massive Irreparable Rotator Cuff Tears: Speed and Biomechanics.

BACKGROUND: Interpositional synthetic patch repairs are a novel method of treating massive irreparable rotator cuff tears. However, surgeons experience difficulty in the arthroscopic insertion of these patches. QUESTIONS/PURPOSES: We compared two methods of arthroscopic interpositional synthetic patch repair: the newly devised slide-and-grip technique, using pre-loaded sliding knots and no arthroscopic knots, and the weave technique, using less arthroscopic knot tying than the earlier mattress technique. Study questions were as follows: (1) Would the slide-and-grip technique take less time than the weave technique? (2) Would the biomechanical strength of the two methods be comparable? METHODS: Fourteen paired ovine infraspinatus tendon ex vivo models of the degenerative human rotator cuff underwent timed repair with a synthetic polytetrafluoroethylene (PTFE) patch, using either the weave technique (n = 7) or the slide-and-grip technique (n = 7). Each was pulled to failure using a tensile testing machine, the Instron 8874. RESULTS: The time to complete the slide-and-grip repairs was shorter (12 ± 0.9 min) than that of the weave repairs (23 ± 1 min). Ultimate load to failure was comparable for the slide-and-grip and weave techniques (211 ± 27 N vs. 295 ± 35 N, respectively), and the slide-and-grip was less stiff (14 ± 1 N/mm vs. 19 ± 1 N/mm). CONCLUSIONS: The slide-and-grip technique took less time than the weave technique for the interpositional patch repair of massive irreparable rotator cuff tears and when correctly performed had comparable biomechanical strength.

Computational Pre-surgical Planning of Arterial Patch Reconstruction: Parametric Limits and In Vitro Validation.

Surgical treatment of congenital heart disease (CHD) involves complex vascular reconstructions utilizing artificial and native surgical materials. A successful surgical reconstruction achieves an optimal hemodynamic profile through the graft in spite of the complex post-operative vessel growth pattern and the altered pressure loading. This paper proposes a new in silico patient-specific pre-surgical planning framework for patch reconstruction and investigates its computational feasibility. The proposed protocol is applied to the patch repair of main pulmonary artery (MPA) stenosis in the Tetralogy of Fallot CHD template. The effects of stenosis grade, the three-dimensional (3D) shape of the surgical incision and material properties of the artificial patch are investigated. The release of residual stresses due to the surgical incision and the extra opening of the incision gap for patch implantation are simulated through a quasi-static finite-element vascular model with shell elements. Implantation of different unloaded patch shapes is simulated. The patched PA configuration is pressurized to the physiological post-operative blood pressure levels of 25 and 45 mmHg and the consequent post-operative stress distributions and patched artery shapes are computed. Stress-strain data obtained in-house, through the biaxial tensile tests for the mechanical properties of common surgical patch materials, Dacron, Polytetrafluoroethylene, human pericardium and porcine xenopericardium, are employed to represent the mechanical behavior of the patch material. Finite-element model is experimentally validated through the actual patch surgery reconstructions performed on the 3D printed anatomical stenosis replicas. The post-operative recovery of the initially narrowed lumen area and post-op tortuosity are quantified for all modeled cases. A computational fluid dynamics solver is used to evaluate post-operative pressure drop through the patch-reconstructed outflow tract. According to our findings, the shorter incisions made at the throat result in relatively low local peak stress values compared to other patch design alternatives. Longer cut and double patch cases are the most effective in repairing the initial stenosis level. After the patch insertion, the pressure drop in the artery due to blood flow decreases from 9.8 to 1.35 mmHg in the conventional surgical configuration. These results are in line with the clinical experience where a pressure gradient at or above 50 mmHg through the MPA can be an indication to intervene. The main strength of the proposed pre-surgical planning framework is its capability to predict the intra-operative and post-operative 3D vascular shape changes due to intramural pressure, cut length and configuration, for both artificial and native patch materials.

Biomechanical comparison of expanded polytetrafluoroethylene (ePTFE) and PTFE interpositional patches and direct tendon-to-bone repair for massive rotator cuff tears in an ovine model.

BACKGROUND: Massive irreparable rotator cuff tears are a difficult problem. Modalities such as irrigation and debridement, partial repair, tendon transfer and grafts have been utilized with high failure rates and mixed results. Synthetic interpositional patch repairs are a novel and increasingly used approach. The present study aimed to examine the biomechanical properties of common synthetic materials for interpositional repairs in contrast to native tendon. METHODS: Six ovine tendons, six polytetrafluoroethylene (PTFE) felt sections and six expanded PTFE (ePTFE) patch sections were pulled-to-failure to analyze their biomechanical and material properties. Six direct tendon-to-bone surgical method repairs, six interpositional PTFE felt patch repairs and six interpositional ePTFE patch repairs were also constructed in ovine shoulders and pulled-to-failure to examine the biomechanical properties of each repair construct. RESULTS: Ovine tendon had higher load-to-failure (591 N) and had greater stiffness (108 N/mm) than either PTFE felt (296 N, 28 N/mm) or ePTFE patch sections (323 N, 34 N/mm). Both PTFE felt and ePTFE repair techniques required greater load-to-failure (225 N and 177 N, respectively) than direct tendon-to-bone surgical repairs (147 N) in ovine models. CONCLUSIONS: Synthetic materials lacked several biomechanical properties, including strength and stiffness, compared to ovine tendon. Interpositional surgical repair models with these materials were significantly stronger than direct tendon-to-bone model repairs.

Use of PTFE patch for pericardial closure after minimal invasive LVAD implantation.

The left ventricular assist device (LVAD) is now a routine therapy for advanced heart failure. The thoracotomy approach for LVAD implantation, in which the left ventricle is approached through a pericardial rent, is becoming popular. We demonstrate closure of the pericardial rent with a polytetrafluoroethylene (PTFE) patch and its advantages.

Role of PTFE Patch Saphenoplasty in Reducing Neovascularization and Recurrence in Varicose Veins.

Varicose veins have a high recurrence rate following surgery. Besides poor surgical technique, majority of these recurrences are attributable to neovascularization after both primary and repeat surgery. Authors have studied the effectiveness of a polytetrafluoroethylene (PTFE) patch interposition between the ligated vein stump and the overlying soft tissue at saphenofemoral junction in decreasing recurrence of varicose veins after initial surgery. Study was conducted on 50 patients of varicose veins with saphenofemoral junction incompetence. Patients were randomly divided into two groups, group A and group B alternately. In group A, standard surgical procedure was done followed by PTFE patch application. In group B, same surgical procedure was applied as in group A, with the exception of PTFE patch application. Patients in both groups were given similar postoperative care. A full venous duplex ultrasound assessment was performed in all the patients postoperatively. Neovascularization was observed in five patients (20 %) of group B, while it was not seen in any of the patients in group A at 1-year follow-up. This difference in neovascularization across the two groups was found to be statistically significant with a p value of 0.0251. Hence, authors concluded that patch saphenoplasty helps in reducing recurrence in varicose veins by decreasing neovascularization at saphenofemoral junction.

Reconstruction of Lateral Capsular Ligament of Temporomandibular Joint with E-PTFE(Gore-tex(R)) Patch

The lateral capsular ligament of temporomandibular joint(TMJ) prevents mandibular condyle from lateral displacement in case of fractures related with condyle. When the condylar fracture with lateral extracapsular displacement occurs, open reduction and reconstruction of capsular ligament must be considered. However, many patients exhibit limitation of functional movements of the TMJ after such surgery. This may be a result of myositis, myospasm, fibrosis of bilaminar zone, adhesion of TMJ capsule. When the joint problem occurs, non surgical treatment must be attempted firstly. But if it fails, the surgical reconstruction must be considered. We reconstructed the lateral capsular ligament of TMJ with E- PTFE(Expanded Polytetrafluoroethylene, Gore-tex(R)) patch after removing scar tissues and adhesions. This surgical method showed improvements in movement as well as the pain of the joint. No side effect has detected from occlusion for about 2 years. There was no foreign body reaction or irritation to the capsule, since E-PTFE was biologically inert. We believe that the E-PTFE patch could be used as primary material of capsular ligament of TMJ reconstruction, insertion material in high tensioned capsule and reinforcement material in weakened capsule.