Dacron diaphragmatic grafts

Dacron

Diaphragrnatic

Grafts

CAPT. MARTIN L. DALTON, JR., MC, USAR, RALPH B. DIXON, B.S., AND CAPT. R. LEE WEST, MC, USAR, Washington, D. C.

From the Division of Clinical Surgery, W’alter Reed Army Institute of Research, Washington, D. C.

F

terial substitute seemed to fulfill all of these criteria. A porous loose weave was selected since others have suggested that such a weave leads to increased ingrowth of fibrous tissue through the wider interstices and an increased tissue incorporation. (Fig. 1.)

AILING to approximate the diaphragm with

sutures, the surgeon is faced with a problem which remains largely unsolved. Certainly a plethora of potential solutions have been suggested. Autologous tissues including skin grafts [I], fascia lata grafts [2,3], adjacent organs [4,5], and pedicled muscle flaps [G-8] have all been used with varying degrees of success. In addition to these, other operative maneuvers such as thoracoplasty [9], multiple rib resections [IO], and phrenic nerve crush [II] have been utilized. Prosthetic adjuncts which have been recommended in the past include Ivalon@ [12], nylon [13], Teflon@ [IS], Marlex@ mesh [15], sponge rubber [16], and tantalum mesh [17]. The existence of over a dozen different methods of treatment attests to the present unresolved status of this problem. Delineation of the problem into specific clinical entities lends some degree of clarity to the selection of a satisfactory method of management. From a review of the literature, it would seem that autologous tissue capable of growth, such as a pedicled muscle flap from the abdominal wall, should be considered the treatment of choice in an infant with a large hernia or absence of the diaphragm [18-201. In the adult, in the presence of conditions such as a large hiatal hernia, traumatic hernia or avulsion, or after resection for primary or metastatic malignancy, prostheses could be used with less difficulty and presumably with less morbidity. The present study, in which Dacron@ felt was used, represents a continuation of the effort to find a more nearly ideal prosthesis. Such a prosthesis should be readily available, easily sterilized, inert, and acceptable as a tissue substitute. Dacron, which serves so well as an ar-

MATERIALS AND METHODS Ten adult mongrel dogs weighing from 10 to 15 kg. were used in this study. The principles of laboratory animal care advocated by the National Society for Medical Research were observed. Using intravenous pentobarbital anesthesia and sterile technic, a left posterolateral thoracotomy was performed through the ninth intercostal space. A segment measuring 5 by 10 cm. of the left hemidiaphragm including the central tendon was excised and replaced by Dacron felt which had been sterilized by boiling in tap water for thirty minutes. The felt was 2 to 3 mm. thick and the individual fiber strength was 60,000 to 117,000 pounds per square inch with elongation between 10 and 40 per cent. The prosthesis was sutured in place after hemostasis was obtained. The initial suture was continuous No. 3-O chromic catgut and this was reinforced by interrupted sutures of No. 2-O silk. The chest was closed in layers and 600,000 units of penicillin was given intramuscularly daily for five days. After three to thirteen months of observation, all animals were sacrificed. After gross evaluation, the graft and the surrounding tissues were excised and hematoxylin and eosin- and Masson-stained sections were prepared for study. RESULTS There were no operative deaths and all dogs survived their individual observation periods. The results are summarized in Table I. There was no incidence of wound infection or empyema and no dog developed a diaphragmatic hernia despite the fact that one dog (A 299)

delivered a litter of six pups ten months after graft placement. Excellent healing was evident 668

American

Journal

of Surgery

Dacron Diaphagmatic

Grafts

1 FIG. 1. Dacrou felt; magnification

X 8 before reduction.

FIG. 2. Photomicrograph of three month old Dacron prosthesis. The circular areas in which arc tiny dark dots are the prosthesis fibers; between the fibers of the prosthesis are collagen fibers. Blood capillaries are near the center and at the lower left of the photornicrograph. Masson stain ; magnification X 110 before reduction.

grossly in each instance.

Intrathoracic adhesions were noted in seven dogs but were not severe in any animal. ,411prostheses were intact and only slight shrinkage had occurred despite a moderate loss of elasticity. Even though the phrenic nerve and its branches were carefully avoided in the original resection, four of the ten dogs were found to have paralysis and atrophy of a portion of the left hemidiaphragm, usually posterolaterally. Microscopic observations were made from four sections taken from each specimen. Since all specimens were of similar size and shape, sections from comparable areas could be taken for study. Three months after Dacron prosthesis placement very healthy ingrowth of connective tissue was evident. Fibroblasts had proliferated TABLE RESULTS

WITH

DACRON

I

DIAPHRAGMATIC

GRAFTS

Dog

Time of Sacrifice (months)

Intrathoracic Adhesions

Diaphragmatic Paralysis

B343 B430 A299 B337 A696 B013 B384 B124 B371 A963

3 11 11 12 12 12 12 13 13 13

None Few Moderate None Moderate Moderate Few None Few Few

Partial Partial i?Co NO Partial No No No Partial

Ii0

among the fibers of the prosthesis and had laid down a stroma of collagen fibers. (Fig. 2.) Numerous blood capillaries were present. No evidence of an inflammatory reaction was present about the individual fibers of the graft or at the periphery where it joined the muscle fibers of the diaphragm by a healthy union of scar tissue. Parietal pleura and peritoneum had completely covered both surfaces of the graft which was totally engulfed in morphologically normal scar tissue. At eleven to thirteen months morphologic changes within the prostheses were characterized by an intense chronic inflammatory reaction which resembled a response to a foreign body. The changes were qualitatively similar in all dogs with the more severe changes being present in the dogs sacrificed at thirteen months. Widespread degeneration of collagen fibers was noted. This inflammatory response began centrally and progressed toward the pleura and peritoneum resulting in a reduction of fibrous connective tissue centrally. The inflammatory exudate was composed of numerous mononuclear cells, lymphocytes, a few plasma cells, and an occasional eosinophil. These cells definitely tended to cluster about the fibers of the prosthesis. In many areas were numerous multinucleated giant cells which were virtually always in contact with a prosthesis fiber. Within the inflamed areas, the collagen fibers were degenerating. The size of the areas of degeneration varied considerably. The degenerating collagen was granular. amor

670

Dalton,

Dixon,

and West

FIG. 3. Thirteen month old Dacron prosthesis. An inflammatory reaction is present with the cells of the exudate tending to cluster about fibers of the prosthesis. Smudgy collagen fibers near the center and at the bottom of the photomicrograph. Masson stain; magnification X 160 before reduction.

FIG. 4. Inflammatory cellular exudate in an eleven month old prosthesis. ,4 multinucleated giant cell is adjacent to a prosthesis fiber. Large mononuclear cells, lymphocytes, and plasma cells are present; there are few collagen fibers. Hematoxylin and eosin; magnification X 475 before reduction.

phous, and eosinophilic. This, plus the exudate of plasma cells, lymphocytes and eosinophils, was mildly suggestive of an immune response to the graft. (Fig. 3 and 4.) Hyalinization had occurred in other areas but was not widespread. Mesothelial and connective tissue regrowth over the prosthesis remained intact. (Fig. 5.) COMMENTS

The use of plastic diaphragmatic grafts is neither original nor unique. Nylon was first used experimentally as a diaphragmatic prosthesis by Adler and Firme in 1957 [13]. They used nylon to avoid the use of tantalum mesh because of its potential rupturing into

FIG. 5. A layer of mesothelial cells covers the surface of a layer of fibrous tissue about a prosthesis. Hematoxylin and eosin; magnification X 160 before reduction.

such vital structures as the aorta or esophagus. Nylon net was preferred to woven material since tissue reaction was less. However, nylon proved to be undesirable because of 83 per cent loss of tensile strength six months after implantation -[21]. Harrison [14] in 1957 used Teflon to replace 80 per cent of the left hemidiaphragm in six dogs. Even though the lung and the abdominal viscera became adherent to the Teflon, only a minimal foreign body reaction was invoked. An open porous weave proved to be more satisfactory since it facilitated formation of a thin fibrous enclosure of the graft which was continuous through the graft interstices. Unfortunately, all dogs were sacrificed by eight months and long term results remain unknown. Ivalon has been used experimentally more than any other plastic material as a diaphragmatic prosthesis. It was first used by Cooley, Grindlay, and Clagett [ZZ] in 1957 in the repair of large experimental hiatal hernia in dogs. The results were characterized by fibrous encasement and infiltration through the graft interstices at six months. Wound healing and tensile strength were excellent. Malm, Sjostrom, and Sternby [23] reported in 1962 on the use of Ivalon in dogs sacrificed at intervals up to two years. Ivalon healed with only minimal foreign body reaction and fibrous tissue ingrowth was abundant. However, beyond nineteen months shrinkage and progressive calcification of the Amevican

Jouunal

of Surgery

Dacron Diaphagmatic prosthesis occurred. As early as 19.38 Pesek and Keeley [24] recommended clinical use of Ivalon as a diaphragmatic replacement, but to our knowledge Marlex mesh is the only plastic material to be successfully utilized clinically [15]. In this case, reported three years after implantation in an infant with congenital absence of the left hemidiaphragm, the results were excellent as judged by the physical appearance of the patient and the roentgenogram of the chest. In the present study, the experimental use of Dacron as a diaphragmatic replacement is reported. Previous implantation studies using squares of Dacron material of 1 cm. had demonstrated complete encapsulation by fibrous connective tissue at fourteen days [21]. If Dacron is properly stressed in production, it forms the strongest of all the synthetic fibers and wet strength is 100 per cent of dry strength [25]. Its resistance to weak acids and alkalies is good even at high temperatures. It is resistant to bacteria and is characterized by low moisture absorption [26]. The early results using Dacron were most encouraging in that excellent healing and healthy ingrowth of fibrous tissue occurred. Sacrificing of the entire group at four to six months would have led to considerably different conclusions than were reached after thirteen months of observation. At between eleven and thirteen months collagen degeneration and chronic inflammation were consistently present. These changes would appear to preclude a satisfactory end result using Dacron material. However, long-term studies of the order of three to four years must be done to ascertain the magnitude of these projected findings. Since loss of elasticity with incipient distortion of the esophageal, aortic, and vena caval openings in the diaphra,m has been mentioned as an indictment against the use of plastic grafts in infants [20], we have replaced the entire left hemidiaphragm of five puppies with Dacron felt. We plan to study these animals for several years prior to sacrifice. In this manner we can determine the degree of diaphragmatic distortion and also the ultimate judgment of Dacron grafts as diaphragmatic substitutes. This will be the subject of a future report. SUMMARY

The use of Dacron diaphragmatic grafts in dogs which were sacrificed at intervals up to Vol. 111, May 1966

Grafts

(ii1

thirteen months is described. From these studies it is apparent that Dacron is not totally satisfactory for this purpose. Other materials should be tested as they become available, and protracted studies using Dacron as well as Teflon and Ivalon should be accomplished. For the present, the use of pedicled abdominal muscle flap should be continued in the infant. The use of plastic materials cannot be recommended for application in human subjects until extremely long-term studies on animals have been completed. REFERENCES

1. GEEVER, E. D. and MERENDINO, K;. d. The repair of diaphragmatic defects with cutis grafts. .Surg. Gynec. & Obst., 95: 308, 1952. 2. SCHAIRER, A. E. and KEELEY, J. L. Experimental use of homologous fascia lata to repair diaphragmatic defects in dogs. Surg. Gynec. & Ohst., 105: 565, 1957. 3. LAUSTELA, E. and VIKKULA, L. A study of the use of synthetic grafts, skin, and fascia lata in the repair of diaphragmatic defects. dnn. chir. ct pvnaec. Fenniae. 52: 437. 1963. 4. W&XBERG, J. Diaphragmatic hernia in infants: surgical treatment with the use of renal fascia. Surgery, 3: 78, 1938. 5. NEVILLE, W. E. and CLOVES, G. H. A., JR. Congenital absence of hemidiaphragm and use of a lobe of liver in its surgical correction. .4rrh. Surg., 69 : 282, 1954. 6. CHISHOLM, T. C. Transthoracic repair of large diaphragmatic hernias. J. Thoraric &u-g., 16: 200, 1947. 7. MEEKER, I. A., JR. and SNYDER, W. H., JR. Surgical management of diaphragmatic defects in the new born infant. Ant. J. Surg., 104: 196, 1962. 8. HOLCOMB,G. W., JR. A new technique for repair of congenital diaphragmatic hernia with absence of the left hemidiaphragm. Surgery, 51: 534, 1962. 9. HEDBLOM, C. A. Diaphragmatic hernia. J.d .dl.A ,, 85: 947, 1925. 10. BIRD, C. E. Division of ribs as an aid in closing a diaphragmatic hernia. Ann. Surg., 104: 993, 1936. 11. ALIVASATOS, C. S., BONELLOS, C. H., AVLAA~IS, G. P., SARVIS, M. C., and RO~AXOS. .i. S. Traumatic closed rupture of the diaphragm. nis. Chest, 46: 435, 1964. 12. JONES, T. W., STEVENSON, J. I;.. JESSEPH, J. E., and HARKINS, H. N. A critical evaluation of polyvinyl sponge (Ivalon) as a vascular and tissue substitute. Am. Surgeon, 2-C: 401, 1958. 13. ADLER, R. H. and FIRME, C. N. The use of Xylon prosthesis for diaphragmatic defects. S&z. Gynec. b Obst., 104: 669. 1957. 14. HARRISON, J. H. A Teflon weave for replacing tissue defects. Surg. Gynec. & Obst., 104: 584, 1957. 15. BENJAMIN, H. B. Agenesis of the left hemidiaphragm. J. Thwack & Cardiovas. Swg., 46: 265, 1963. 16. BASS, M. M. The replacement of the diaphragmatic

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Dalton, Dixon, and West

defects with a rubber sponge. Eksp. khir. anest., 4: 47, 1959. MONAHAN, D. T. Eventration of the diaphragm repaired with Tantalum mesh. ~lr,e England J. Med., 244: 475, 1951. RAVITCH, M. M. and HANDELSMAN,J. C. Lesions of thoracic parietes in infants and children. S. Clin. North Anterica, 32: 1397, 1952. MEEKER, 1. A., JR. and NICHOLS, J. N. Congenital diaphragmatic hernia in the newborn ll’eest.J. Surg., 67: 42, 1959. ROSEXKRANTZ, J. G. and COTTON, E. K. Replacement of left hemidiaphragm by a pedicled abdominal muscular flap. J. Thoracic b Cardiooas. Surg., 48: 912, 1964. HARRISON, J. H., SWANSON, D. 8, and LINCOLN, A. F. A comparison of the tissue reactions to plastic materials. Arch. Surg., 74: 139, 1957.

22. COOLEY, J. C., GRINDLAY, J. H., and CLAGETT, 0. T. Esophageal hiatus hernia-anatomic and surgical concepts with special reference to the experimental use of an Ivalon prosthesis in the repair. Surgery, 41: 714, 1957. 23. MALM, A., SJBSTR~M,B., and STERNBY, N. H. Longterm experimental evaluation of Ivalon in repair of diaphragmatic defects, Acta chir. scandinao., 124: 114, 1962. 24. PESEK, I. G. and KEELEY, J. L. Polyvinyl formalinized (Ivalon) sponge in repair of diaphragmatic hernia. Arch. Surg., 77: 18, 1958. 25. SIMONDS, H. R. A Concise Guide to Plastics, pp. 61, 97. New York, 1957. Reinhold Publishing Corp. 26. GOLDING, B. Polymers and Resins, p. 285. Princeton, New Jersey, 1959. D. Van Nostrand Co., Inc.

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