Morphological Evaluation of the Tissue Reaction to Subcutaneous Implantation of Decellularized Matrices

Based on the data of morphological analysis, we performed histological evaluation of rat tissue reaction to subcutaneous implantation of decellularized matrices of intrathoracic organs and tissues. Cell composition of the inflammatory infiltrate was analyzed, and the dynamics of macrophage and T and B lymphocyte content was assessed on days 7 and 14 of the experiment. It was found that the reaction to implantation depended not only on the quality of decellularization and efficiency of removal of antigen molecules, but also on the original histological structure and quality of preimplantation processing of the transplant.

Reconstruction of thoracic esophagus with pediculated diaphragmatic flap in dogs

PURPOSE

To verify whether pediculated diaphragmatic flaps were suitable to correct iatrogenic wounds in dog's esophagus injuries.

METHODS

Seven dogs were submitted to resection of a segment of the esophageal wall, which was then corrected by suturing a pediculated diaphragm flap. Endoscopic evaluation of the esophageal wall was done forty days after the surgical procedure.

RESULTS

Three animals died, one due to implant ischemia, caused by strangulation of the phrenic artery; other due to wound infection; and the last, due to mediastinitis. Scar retraction was observed, however, there was no stenosis, allowing the passage of a 9,8 mm probe with no difficulty. The limits between the implants and the native esophagus were indistinguishable, and the implant was covered by esophageal mucosa.

CONCLUSION

The diaphragmatic flaps are suitable on the restoring of continuity in dog's thoracic esophagus.

Creation of Coronary Sinus Using Left Atrial Diaphragm in the Patient With Cor Triatriatum and Unroofed Coronary Sinus

Surgical correction of cor triatriatum with unroofed coronary sinus consisted of creation of the coronary sinus using the left atrial diaphragm and closure of the atrial septal defect in an adult patient. No materials other than intracardiac components were used to repair all anomalies.

The diaphragmatic flap: A multiuse material in thoracic surgery

BACKGROUND

The use of diaphragmatic pedicle flaps for reconstructive procedures in thoracic surgery is not very popular. Nevertheless, it provides considerable advantages.

METHODS

Our experience covers 10 years (1987-1997) with a total of 25 patients in whom the diaphragmatic flap was used for different purposes. In 6 patients we used the diaphragmatic flap to protect the bronchopleural fistula at its early onset, which was not beyond 12 hours from the clinical diagnosis. We performed prophylactic suture protection after neoadjuvant therapy in 9 high-risk patients who underwent pneumonectomy and in 2 who underwent sleeve lobectomy. Postpneumonectomy pericardial defect repair was performed in 4 patients. In another 4 patients the diaphragmatic flap was used after spontaneous (n = 2) and iatrogenic (n = 2) lesions of the esophagus after 24 to 72 hours.

RESULTS

No perioperative mortality was recorded. Complications were mainly related to the severe preoperative conditions of the patients: arrhythmia, respiratory insufficiency, and empyema. We report only 2 cases of minimal persistent bleeding from the chest tube, which spontaneously ceased. For those patients who survived for more than 1 year (n = 11), no diaphragmatic hernias were recorded. Bronchopleural fistulas and pericardial defects healed in all instances. The diaphragmatic flap was also effective in bronchopleural fistula. A late fistula caused by cancer relapse at the bronchial stump developed in only one patient. Excellent repair was achieved in all patients with esophageal lesions.

CONCLUSIONS

We conclude that the diaphragmatic flap can be considered a practical, safe, and redundant material particularly indicated for defect or fistula closure and for suture line protection in the thoracic cavity.

Heterotopic neogenesis of skeletal muscle induced in the adult rat diaphragmatic peritoneum: ultrastructural and transplantation studies

During the course of a mild chemical peritonitis, new skeletal muscle fibers develop and persist over a twelve-month interval in the diaphragmatic peritoneum. Light and electron microscopic studies revealed that the ectopic fibers developed from myoblasts and myotubes to fully differentiated muscle cells in the same manner as normally situated skeletal muscle. The ectopic fibers were separated from the intrinsic muscle by dense connective tissue and an elastic lamina. Diaphragms taken from normal rats and transplanted to the omentum of isogeneic recipients also developed skeletal muscle neogenesis in the same ectopic location as in the normal diaphragm. Satellite cells, reactive fibroblasts in the peritoneum, mesenchymal stem cells or blood-borne myoblast precursor cells could be the source of these ectopic muscle fibers. The results of the present studies, however, cannot provide conclusive evidence for the origin of the new muscle fibers. Regardless of their source, the methods employed may represent a unique model for the development and prolonged maintenance of skeletal muscle fibers in a heterotopic location in vivo.

Comparison of omentum, pleura and diaphragm for tracheal autograft survival in rats

Pleura, diaphragm, pericardial fat pad, intercostal muscles and omentum can be used to protect and revascularize the bronchial suture line. To compare the efficiency of pleura, diaphragm and omentum, an experimental study was designed. Heterotopic tracheal autotransplantation was performed in 15 rats. Animals were divided into three groups; omentum, diaphragm and pleura. Tracheal Segment Necrosis Scoring System was used for pathologic examinations. Pleural and diaphragmatic groups showed the least necrosis and there was significant statistical difference among these groups and omental group (P < 0.05). Our study showed that pleura and diaphragm could be used as safely as omentum for protection and survival of bronchial suture lines.

Early closure of the postpneumonectomy bronchopleural fistula by pedicled diaphragmatic flaps

In the past, several methods for closure of postpneumonectomy bronchopleural fistula have been proposed. Herein we describe a technique to close a bronchopleural fistula using a mobilized diaphragmatic flap sutured directly to the fistula edges. This maneuver improves the blood supply to the bronchial stump and may reduce residual pleural cavity. To prevent bacterial contamination of the pleural space, the procedure should be performed immediately after the diagnosis.

The two stage tracheostomy as a safe technique in instances of severe coagulopathy

A simple two stage tracheostomy procedure is described for use in respirator-dependent patients in intensive care units. It is useful in patients in whom tracheostomy is indicated, but refractory coagulopathy is a deterrent.

Use of the diaphragm to reinforce anastomosis of the intestines

Use of a diaphragmatic flap to buttress and help secure persistent intestinal fistula is described. The potential for the use of muscle flaps in the management of recurrent intestinal fistula is presented.

[Cardiomyoplasty: a new alternative in chronic heart failure]

The technique of cardiomyoplasty to support the failing heart as applied in the first two patients in The Netherlands is reported. Indications are presented for the selection of patients who might benefit from a cardiomyoplasty procedure, considering its experimental nature.

Treatment of esophageal achalasia (cardiospasm) with diaphragmatic graft. Twenty-five years' experience

Long-term results are presented in 60 patients (4 to 50 years old) who underwent a diaphragmatic graft procedure for relief of cardiospasm (achalasia) from 1962 through 1987. The operative technique involves construction of a pedicle flap of diaphragm. The muscular defect on the lower segment of the esophagus and the transplanted diaphragmatic pedicle that is sutured to the defect must be the same size. Immediate operative results were good. Only one complication developed, a case of pneumonia that was cured. The patients were followed up from 11 months to 25 years. Two patients were lost to follow-up, 55 had excellent results, and three patients still had nausea and heartburn but were better than before the operation. This procedure has three advantages: (1) It prevents the development of fistulas and diverticula at the site of the esophageal muscular defect; (2) it effectively eliminates both restenosis resulting from scar tissue and reflux esophagitis; and (3) it allows the cardia to recover its normal function and the esophagus to return to normal size at the site of the operation.

Treatment of esophageal achalasia (cardiospasm) with diaphragmatic graft: report of 44 patients

Results with the use of a diaphragmatic graft in the surgical relief of achalasia are reported for 44 patients. The operative technique involves construction of a pedicle flap of diaphragm the size of the muscular defect on the lower segment of the esophagus and suture of the transplanted diaphragmatic pedicle to the site of the esophageal muscular defect. Immediate operative results were good; there was only one complication, a case of pneumonia that was cured. Patients were followed from 3 months to 19 years. Two patients were lost to follow-up. Excellent results were obtained in 39 patients; 3 patients still had nausea and heartburn, but were better than before operation. This procedure has three advantages: (1) it prevents occurrence of fistula and diverticulum at the site of the esophageal muscular defect; (2) it effectively eliminates formation of restenosis due to scar and reflux esophagitis; and (3) it allows the cardia to recover its normal function and the esophagus to return to normal size at the site of operation.

Effect of electrical stimulation on diaphragmatic muscle used to enlarge right ventricle

The effect of chronic electrical stimulation on muscle mass of pedicled diaphragmatic muscle grafts (DMGs) implanted into the right ventricle was studied in 21 dogs. Nineteen dogs, followed up to 70 days (mean, 34 days), were divided into three groups. In six dogs (control) the DMG was not stimulated. In six other dogs the DMG was stimulated at 50 stimuli/min with a fixed-rate unipolar pacemaker. In seven animals the graft was paced 1:1 with the dog's own rhythm with an R-wave synchronous pacemaker. Surface area of the DMG decreased 34% to 43% (P less than 0.05) in all dogs. DMG thickness increased in all dogs (P less than 0.05). The increase was 29% for control animals and 132% and 134% for the two paced groups. The volume of the DMG decreased 24% in the nonpaced animals but increased 29% and 51% in the two paced groups. Histologic studies showed some degree of muscle degeneration and atrophy in all grafts. However, morphometric studies showed relatively normal fiber diversity in paced grafts. Fiber size decreased in nonpaced grafts, indicating muscle atrophy. Perfusion studies with labeled microspheres and silicone injections demonstrated collateral circulation with the host ventricle as early as 28 days. However, total blood flow to DMGs implanted for 4 to 6 weeks averaged only 32% of the blood flow to normal ventricular myocardium. Chronic electrical stimulation of DMGs reduces muscle degeneration and atrophy and is associated with an increase in graft thickness and volume.

Replacement of ventricular myocardium with diaphragmatic skeletal muscle: short-term studies

A pedicled diaphragmatic skeletal muscle graft was used to replace a portion of resected right ventricle in 35 dogs. The graft contracted when electrically stimulated directly or via the phrenic nerve before and after insertion. The electrical pacing threshold was lower for phrenic nerve stimulation (0.9 +/- 0.20 mamp) than for direct graft stimulation (2.3 +/- 1.19 mamp). The heart could be captured and paced by stimulating the muscle graft with higher current (16.2 +/- 4.49 mamp). The delay from pacing stimulus to muscle graft contraction when the graft was paced directly was 10 msec. The epicardial activation time delay when the heart was paced through the muscle graft was 27.0 +/- 9.08 msec. When the muscle graft pedicle was transected, the graft lost its ability to contract. The heart, however, could still be captured electrically through the graft for up to 4 hours. Strain gauge studies of the nonstimulated muscle graft showed tension development during pre-ejection ventricular contraction identical to that of the right ventricle. In the ejection phase, muscle graft tension slowly declined. The stimulated muscle graft developed active tension and echographically demonstrated muscle thickening during contraction. This study demonstrates that a vascularized, neurally innervated diaphragmatic muscle graft can be placed into the right ventricle. The graft retains its ability to contract in response to direct or phrenic nerve stimulation. It can be made to contract during any phase of the cardiac cycle. Thus diaphragmatic muscle grafts may provide a method to augment ventricular cavity size with synchronously contracting muscle.

Diaphragmatic pedicle flap for treatment of Boerhaave's syndrome

A case of spontaneous perforation of the esophagus is described, which was managed by thoracotomy, primary closure, and reinforcement of the suture line with as diaphragmatic pedicle flap. The advantages of this technique are discussed.

Diaphragmatic muscle and cardiac surgery

Images