Infection as a late complication in vascular grafting

Infection

as a Late

Complication Grafting*

EDWARD J. HELBING, JR.,M.D. AND ROBERT P. HOHF, From tbe Departments of Surgery, Northwestern University Medical School, Chicago, and the Evanston Hospital Association, Evanston, Illinois.

ASCULAR substitutes have been used occasionahy in traumatic surgery for many years but onIy recentIy their use has become widespread in the treatment of arterioscIerosis obliterans. In 1908, CarreI [I] reported on the then current status of bIood vesse1 surgery for traumatic lesions. He mentioned a few successfu1 resuIts and stressed the importance of carefu1 suturing of the vesse1 to prevent thrombosis in the graft. The current progress in this field was started by dos Santos [2] who described his initia1 attempts at arterial reconstruction for obIiterative arterioscIerosis in 1947. He used mainIy a method of curettement of the arteria1 Iumen which he caIIed thrombo-endarterectomy. The next advance in technic was the use of bypass grafts to carry bIood around the occIuded areas or to bridge the defects folIowing excision of the diseased arteries. The first grafts were arteria1 homografts preserved by chemicals or by freezing and drying. RecentIy, these have been repIaced by inert fabric grafts of nyIon, Dacron@ or Teflon.@ Since this fieId is new, reports are just being pubIished as to the long-term effects of these foreign bodies in both human beings and experimenta animaIs. The most frequent earIy compIication of vascuIar grafting has been thrombosis of the graft caused by inadequate runoff of bIood dista1 to the graft. This is caused by generaIized obIiterative disease of smaI1 dista1 vesseIs, such as the anterior and posterior tibia1 arteries in the Ieg, and is usuaIIy obvious when no puIses are paIpabIe and the Ieg is coId * Accepted 1962

Evanston, Illinois

tweIve to twenty-four hours after surgery. At reoperation, if adequate backflow cannot be obtained, eventua1 amputation may be necessary. Some Iimbs may be saIvaged by “extensive endarterectomy” as described by TrippeI et a1. [j] and others. Hemorrhage is occasionally found as an immediate compIication because of inadequate suturing or suturing into a weakened area of arterial waI1; however, this compIication is rare. Infection is a serious early compIication of vascuIar grafting and can lead to hemorrhage and possibIy thrombosis in both homografts and prostheses. Infection tends to destroy the eIastic fibers of the media in arteria1 homografts. This may Iead to aneurysm formation and rupture of the graft up to four months foIIowing surgery. Harrison [4] has shown in dogs that a11 Iayers of the graft necrose because of the acute inflammatory reaction. Even if the infection is successfuIIy combatted, the eIastic hbers are already destroyed, weakening the graft and making it more Iikely to rupture. Hemorrhage, however, is much more IikeIy because of separation at the suture Iines. Infection causes a softening of homografts with resuItant puIIing out of the sutures as we11 as enzymatic digestion of the fibrin seaI. The elastic layer of the adjacent artery is less effected by infection than that of the homograft. VascuIar prostheses of nyIon, Dacron@ or Teflon@ are much safer to use because they wiII not rupture in the face of infection. StiII, because of arteritis, sutures may puI1 out of the adjacent artery, Ieading to severe and often fata bleeding. SchrameI and Creech [T] report this compIication in three of six patients in whom infection deveIoped foIIowing insertion

V

American Journal of Surgery, Volume 103, May

M.D.,

in Vascular

for pubtication

544

December

18, 1961.

Infection

as a Late

CompIication

of arterial prostheses. In several instances, however, the grafts continued to transport blood even though exposed in the base of the wound. They call for early active treatment of’ kvound hematomas and abscesses. Foster, Bcrzins and Scott [6] compared survival rates in dogs in which nylon prostheses and arterial homografts were placed in the presence of infection. Thev found, discounting dogs dying of peritonitis, that twenty-six of thirty-one animals with arterial homografts died of hemorrhage, but that only six of twenty-two with nylon prostheses died in this manner. Harrison [J] has reported an increase in the incidence of thrombosis in arterial prostheses when the surrounding area is infected. He feels that a thicker fibrin lining is formed in the prosthesis as a reaction to the infection. This lining may Iater contract, causing irreguIarity or kinking of the prosthesis foIlowed by thrombosis. However, Foster, Berzins and Scott [h) found a similar percentage of thrombosis in their infected dogs and noninfected controls, and thus believe that infection does not increase the likelihood of thrombosis. This question still remains to be answered. Prostheses, then, have proved their superiority over homografts. They are easily sterilized and will conduct blood even without soft tissue support. They will not rupture in the face of infection as wilI a homograft. As a foreign body, however, they may resist al1 attempts to eradicate infection. Because the adjacent blood vessel is softened, a false aneurysm with leakage of blood resuIts. The Iong-term fate of prostheses is just beginning to be known. Edwards [7] reported that Teflon prostheses after several years become rigid so that the crimping does not prevent kinking in the area of joints. This may suddenly shut off the blood Aow causing thrombosis. Because of these objections, it appears that endarterectomy is again becoming the procedure of choice in vascular reconstruction, with the use of prostheses as a vaIuahle adjunct in selected patients. The following case reports illustrate experiences we have had with complications of vascular grafting secondary to infection. The first illustrates the d&cuIties in trying to eradicate infection about a nyIon arteriaI prostheses and stresses the importance of absolute sterility during the operative procedure. The second describes a spontaneous 545

in VascuIar

Grafting

secondary infection involving a nylon prosthesis one year following implantation; a complication not previously recorded. CASE I. W. Ii., a fifty-four year old white man, was admitted to the Evanston fIospital on August 22, 1957, with a seven year history of increasing intermittent claudication caused by obstruction at the aortic bifurcation. Bilateral femoral arteriograms performed through small groin incisions, because of the absence of femoral pulsations, revealed patent superficial femoral arteries in the thighs. Therefore, on August 29, 1957, a TappEdwards nyIon aortic bypass prosthesis was placed in the abdomen to circumvent the obstructed aorta. The previously made groin incisions w.crc’ utilized for the distal anastomoscs to the superficial femoral arteries. In spite of antibiotics, the groin incisions bccamc infected and several sudden hemorrhages ncccssitatcd returning the patient to surgery on Septcmber 5 for ligation of the distal prosthetic arms. Nylon extensions were passed through new incisions from the prosthesis to the distal superficial femorat arteries, bypassing the infected groin wounds. The known infective organism nonhemolytic Staphylococcus aureus was treated vigorously with antibiotics and local wound therapy for the next several months. Eventually, after several hemorrhagic episodes, the wounds appeared well healed and the patient was discharged afebrile on December 4, 1957, three and a half months after admission. He was readmitted December 28, 1957, with reappearance of wound infection and hemorrhage. All treatment was to no avaiI and hc died suddenIy with severe abdominal and back pain. Autopsy revealed a massive rctroperitonea1 hemorrhage secondary to two leaks at the proximal anastomosis. One was from a ruptured 2 cm. aneurysm at the suture line. (Fig. I.) The aorta proximal to the anastomosis was distinctIy in\,olved with arteriosclerotic plaques and aortitis; however, the graft and its lining wcrc in good condition. RecentIy, Smith and Szilagyi 181 have reported eleven patients with deep wound infection in conjunction with pIastic bypass prosthcscs. Six hemorrhaged, four fatally, in spite of local wound drainage, antibiotics and heat. In these situations, the suture Iines cannot advance to complete healing because the fibrin seal is Iysed by enzymes activated by the infection. Thus, a false aneurysm is formed at best, and usuaIIy fatal hemorrhage occurs. Smith and SziIagyi [X] believe that the graft acts as a sequestrum and, thus, must be removed at the first sign of a deep wound infection if the patient is to survive. However, they have never known of a patient to live following remova of an abdominal aortic graft, so in these patients

HeIbing, Jr. and Hohf

FIG. I. Photograph of the proximal suture Iine taken during the autopsy showing the aneurysma diIation and perforation. The opening of the renaI artery is just pro&a1 to this. the only treatment.

possibIe

hope

Iies

with

conservative

inserted to bypass the femora1 obstruction. He did we11 postoperativeIy with relief of symptoms; however, one year Iater thrombosis of the graft required insertion of a new prosthesis. In August, 1959, the patient had an episode of furuncuIosis of the left groin and scrotum which responded we11 to antibiotics and moist heat. One month later he deveIoped a soft, nontender, nonpuIsating mass 4 by 6 cm. in size which began in the right mid-thigh and extended aIong the femora1 cana to the knee. (Fig. 2.) An arteriogram reveaIed the femora1 graft and superficia1 femoral artery to be patent. Aspiration of the mass produced IO cc. of thick black fluid from which was cuItured coagulase positive StaphyIococcus albus; the same organism was discovered in numerous smaI1 furuncles present on the patient’s back. In spite of antibiotic therapy, the mass continued to enIarge, necessitating expIoration of the right thigh on October 13, 1959. A Iarge hematoma was found surrounding the patent and puIsating graft. (Fig. 3.) The artery, at the site of the distal anastomosis, was quite friabIe and seemed to be the source of bleeding. The graft was detached, and the femora1 artery was Iigated. HeaIing, thereafter, was without incident. Fortunately, the right foot remained viabIe, and the patient was abIe to resume waIking satisfactoriIy with one bIock cIaudication. It seems IikeIy in this patient that one year foIIowing insertion of the prosthetic graft a transitory bacteremia occurred during the episode of furuncuIosis. Organisms may have Iodged at the distal anastomosis because of eddies in the bIood fIow, much the same as occurs in subacute bacteria1 endocarditis. The resuIting arteritis and softening

Groin incisions are highIy susceptibIe to infection as the skin in this area is moist and diffIcuIt to cleanse. In our patient, the reopening of the groin incisions, when pIacing the graft, undoubtedIy Ied to the wound infections. Femoral cutdowns were done for the arteriograms because no femora1 puIses were paIpabIe, and it was unknown whether or not the arteries were patent. It was not anticipated preoperativeIy that it wouId be necessary to extend the graft ends as far distaIIy as the femoraIs; thus, the minor reaction and infection about the sutures were ignored. When it was apparent that femora1 extensions were required for a successful graft, the cut-down wounds were reopened with trepidation. In retrospect, new incisions distaIIy shouId have been made. Once the infection developed our onIy chance of saving the patient’s Iife was to utilize IocaI and systemic antibiotic treatment because compIete remova of the graft wouId have been surely fatal. Extension of the dista1 ends of the graft was ineffectua1 because the organisms stiI1 surrounded the nyIon graft and could migrate to the new suture Iines. The final retroperitonea1 hemorrhage at the proximal suture Iine was not expected and was caused by a rupture of a faIse aneurysm, formed at the suture Iine, secondary to the infection. CASE II. D. S., a forty-nine year old white man, entered the Evanston HospitaI JuIy z I, 1957, compIaining of intermittent claudication in the right Ieg of four months’ duration. A right femora1 arteriogram reveaIed a 5 cm. obstruction in the adductor cana with a good distal runoff; on JuIy 24 a Tapp-Edwards nyIon prosthesis was

546

Infection

as a Late

FIG. 2. Preoperative right thigh.

FIG. 3. Photograph taken at operation from the popliteat space to the left.

Complication

photograph

in Vascdar

Grafting

showing the mass at the inner aspect of the

showing the patent

nyIon prostheses

547

surrounded

by a hematoma

originating

HeIbing,

Jr.

of the vessel wail produced a Ieak which couId not be corrected without remova of the foreign materia1. There is apparently no way to sterilize nonliving subtances in vivo. The infection could have resuIted from contamination of the prosthesis when implanted. Staphylococcus can remain dormant for Iong periods of time before producing progressive infection. This has been the experience of neurosurgeons in connection with cranial prostheses. However, the culturing of a similar organism from the patient’s skin lesion favors the first possibility in our opinion. This complication has not been reported, as yet, with nylon arterial prostheses but certainly should occur as more prostheses are utilized. Almost all patients can be expected to have a transient bacteremia at some time and thus might be susceptibIe to infection around the graft. This raises the question as to whether or not prophyIactic antibiotics should be used in all patients who have arterial prostheses. Certainly all bacteria1 infections should be vigorousIy combatted earIy in their course and a cIose follow-up kept on al1 such patients.

and

Hohf

implantation of a nylon femoraI bypass graft. Such experiences may help to explain the recent repopularization of endarterectomy for arteriosclerotic lesions of the lower extremity. ADDENDUM

Bradham, Cordle and McIver have published the results of a recent experiment in the December, I 961, issue of Annals of Surgery. They produced a staphylococcus aureus bacteremia in dogs with Teflon aortic prostheses. Organisms were implanted spontaneousIy at the prosthetic suture Iines causing inffammation and in some cases thrombosis. This would support our contention that bacteremia is a serious condition in these patients and can lead to infection about the graft. REFERENCES I. CARREL, A. Results

These patients illustrate the fact that infection is a serious problem with arterial bypass grafts and will most IikeIy cause faiIure of the graft. These experiences, and others like them in other centers, have provided impetus to a swing back to endarterectomy for arteriosclerosis obliterans with the use of prostheses in seIected patients only. SUMMARY

A review of the literature reveals the seriousness of infection in vascuIar grafting. To illustrate this complication, two case reports are presented. In the first instance, infection of an aortic graft at the time of surgery Iinally resulted in the patient’s death from massive hemorrhage live months postoperative. The second patient represents, we believe, the first reported spontaneous infection secondary to a transient bacteremia one year following

548

of the transpIantation of bIood vessels, organs, and limbs. J. A. M. A., 5 I: 1662, 1908. 2. DOS SANTOS, J. C. Sur Ia disobstruction des thromboses arterielIes anciennes. M&n. Acad. cbir., 73: 409. 1947. 3. TRIPPEL, 0. H., BERNHARD,V. M. ~~~LA~FMAN, H. Limb salvage in occIusive arteriat disease of the Iower extremities. Arch. Surg., 81: 357, 1960. 4. HARRISON, J. H. Inffuence of infection on homografts and synthetic (TeAon)@ grafts. Arch. Surg., 76: 67, 1958. 5. SCHRAMEL, R. J. and CREECH, O., JR. Effects of infection and exposure on synthetic arteriat prostheses. Arch. S&g., 78: 271,‘ 1959. 6. FOSTER. J. H.. BERZINS. T. and SCOTT. II. W.. JR. An experimenta study of arterial repIacement in the presence of bacteria1 infection. Surg. Gynec. em Obst., 108: 141. 1959. 7. EDWARDS, W. S. Late occlusion of femora1 and poplitea1 fabric arteria1 grafts. Surg. Cynec. &+ Obst., I IO: 714. 1960. 8, SMITH, R. F. and SZILAGYI, D. E. Healing comphcations with pIastic arteria1 implants. Arch. Surg., 82: 34, 1961.