Case Reports

Thoracoabdominal Aortic Aneurysm Repairin Cardiac Transplant Recipients

Ignacio Segura, MD, Leopoldo Fernandez, MD, Gregorio Rabago, MD, andRafael Llorens, PhD, Pamplona and Tenerife, Spain

We present here two cases of asymptomatic thoracoabdominal aortic aneurysms that weresuccessfully operated on in heart transplant patients 8 and 23 months after transplantation.Thoracoabdominal aortic aneurysm was present prior to transplantation in one patient. In theother patient only the abdominal aortic aneurysm was found before transplantation. Indicationsfor transplantation were ischemic and valvular cardiomyopathy. Surgical aortic aneurysm repairwas performed with the standard technique. Both patients were discharged from the hospital.The possible contributing factors to the development and enlargement of aortic aneurysms andperioperative assessment are also discussed. Radiologic surveillance is warranted in any hearttransplant recipient with abdominal or thoracoabdominal aortic aneurysms because of the morerapid aneurysm expansion. (Ann Vasc Surg 2000;14:669-672.)DOI: 10.1007/s100169910119

Cardiac transplantation has become a successfultherapeutic option for selected patients with end-stage cardiac disease. Survival after cardiac trans-plantation has been improved, with reported ratesof 94%,1,2 78%,3 and 72%1,2 at 1, 5, and 10 years,respectively. Because of this success, it is likely thatheart transplant recipients may be subjected toother surgical procedures. Despite the increasingsize of the heart transplant population, the litera-ture on surgical repair of aortic aneurysms (AA) isstill limited.4-6 Resection of abdominal aortic aneu-rysm (AAA) after cardiac transplantation has beendescribed before in the medical literature.7 To ourknowledge this is the first report of successful elec-tive repair of thoracoabdominal aortic aneurysms(TAAA) in cardiac allograft recipients.

CASE REPORT

Case 1

A 57-year old man underwent orthotopic heart trans-plantation in January 1994 for end-stage cardiac failure12 years after an aortic valve replacement. A pretrans-plant computed tomographic (CT) scan showed a 5-cmabdominal aortic aneurysm (AAA). The immediate post-transplantation period was unremarkable, and he wasdischarged on standard triple-therapy immunosuppres-sion (cyclosporine A, azathioprine, and prednisone). Hisejection fraction (EF) improved from 15% before trans-plantation to 65% after transplantation, which has beensustained. One year after transplantation he was hyper-tensive (150/90 mmHg), requiring intake of calcium-channel blockers (diltiazem). The lipid profile was nor-mal. Routine ultrasonographic check-ups revealed a pro-gressive increase in the size of the AAA. CT examinationperformed 6 months later showed the presence of aTAAA that began in the distal half of the descending tho-racic aorta and extended to the entire abdominal aorta(Crawford type III) with a maximum transverse diameterof 5 cm. At 20-month follow-up, CT examination showedan increase in the diameter of the TAAA, which reached6 cm. Arteriographic results mirrored the CT findings. His

From the Departamento de Cardiologıa y Cirugıa Cardiovas-cular, Clınica Universitaria, Pamplona (L.P., G.R.), and Hos-piten Rambla, Santa Cruz de Tenerife, Tenerife (I.S., R.L.),Spain.

Correspondence to: I. Segura, MD, Hospiten Rambla, Ram-bla General Franco 115, 38001 Santa Cruz de Tenerife, Tener-ife, Spain.

669

coronary angiography was normal. Because of the size ofthe aneurysm, surgery was proposed. After a thoraco-phrenolaparotomy, the patient was operated on throughan extraperitoneal approach. The thoracic aorta and iliacarteries were clamped and a 30-mm, collagen-impregnated, woven Dacron graft was interposed. Afterthe proximal anastomosis had been completed, the inter-costal arteries from T10 to T12 were anastomosed to thegraft. The graft was clamped at a lower level and theceliac axis, superior mesenteric, and right renal arterieswere attached to the graft as a patch. The left renal arterywas anastomosed as a separate patch because of the ex-cessive distance between both renal arteries. Aftercompletion of this anastomosis, the clamp was placed be-low the renal arteries and the distal suture was formed.Nitroprusside and dopamine infusions were instituted forblood pressure control and optimization of renal perfu-sion. No extracorporeal bypass was employed. No specialpharmacological measures were employed to prevent spi-nal cord ischemia. The patient was extubated 6 hr afterthe operation. Azxathioprine, cyclosporine, and steroidswere administered intravenously for the first 2 days. Onthe third postoperative day, the patient resumed his oralimmunosuppressive regimen. After an uncomplicatedpostoperative course, he was discharged from the hospital10 days after surgery. At 40 months follow-up, the pa-tient is doing well.

Case 2

In June 1995, a 54-year old male with a history of hy-pertension and hypercholesterolemia received an ortho-topic cardiac transplant for cardiac failure related to isch-emic cardiomyopathy with a left ventricular EF of 20%.His past medical history included left nefrectomy 22 yearsbefore. At the time of transplantation, CT showed a 6-cmthoracic AA and a 6-cm infrarrenal AA. The postoperativecourse was complicated with a 3B rejection episode,which was successfully managed with steroid pulse. Hewas discharged home on the 10th postoperative day withstandard triple drug immunosuppressive therapy. Aftertransplantation the patient continued to suffer from hy-pertension and hyperlipidaemia, for which he was receiv-ing nifedipine and simvastatine. Three months later, one3A rejection episode was observed, which was success-fully managed with metilprednisolone and OKT-3. Sevenmonths after transplantation the transverse diameter ofthe thoracic and abdominal aorta, measured by CT,reached 9 and 7 cm, respectively. His EF at this time was55%. Considering the rapid growth of both aneurysms,surgery was planned. Angiography confirmed normalcoronary vessels. After a thoracophrenolaparotomy, thethoracic aorta and abdominal aorta were clamped and thedistal half of the descending thoracic aorta was replacedwith a 30-mm, collagen-impregnated, woven Dacrongraft. Two holes to accomodate the intercostal arterieswere excised. After completation of this anastomosis, theinfrarrenal aorta and both common iliac arteries wereclamped and a 22 × 1 mm bifurcated woven Dacron graftwas implanted between the infrarrenal aorta and both

common iliac arteries. No extracorporeal bypass was em-ployed. No special pharmacological measures were em-ployed to prevent spinal cord ischemia. The patient wasextubated 24 hr after operation. Azxathioprine, cyclo-sporine, and steroids were administered intravenously forthe first 2 days and thereafter were given orally. The post-operative course was uneventful except for an elevationof serum creatinine. Low-dose dopamine was adminis-tered and renal function improved progressively. The pa-tient was discharged on day 14 after operation. As ofApril 1999, the patient is alive and well.

DISCUSSION

There are few reports in the literature regardingTAAA after heart transplantation.8 Although thereare several reports concerning the successful repairof AAA in cardiac allograft recipients,4,8,9 surgicaltreatment of TAAA after heart transplantation hasnot been previously reported. Here we present ourexperience with elective repair of TAAA in two car-diac transplant recipients.

The case history of the first patient is interestingbecause he had an AAA prior to transplantationthat extended into the thoracic aorta after trans-plantation. It has been reported that the incidenceof AA after heart transplantation is increased inthose patients with ischemic cardiomyopathy.1,9

Moreover, in initial reports concerning this issue, itwas pointed that these incidents were limited topatients with ischemic cardiomyopathy.1 This wasnot the case in our experience, since in case 1 thepatient underwent heart transplantation because ofvalvular cardiomyopathy. In patient 2, the TAAAwas present before transplantation and he under-went heart transplantation for ischemic cardiomy-opathy.

The expansion rate of AA in heart transplant re-cipients has been demonstrated to be greater thanthat in nontransplant patients.1,9 Several factorshave been involved in the development and en-largement of AA in heart transplant recipients: im-proved cardiac output1,9 and new or worsened sys-temic hypertension1,9 after transplantation, and anincrease in shear stress of the aortic wall, contrib-uting to aneurysm formation and rupture.10-12

Immunosuppresive agents such as cyclosporineand steroids have been shown to cause hyperten-sion.8,13 Moreover, steroid therapy has been asso-ciated with the development and rupture of AA inseveral experimental models7,14 and with the for-mation of aneurysms in patients receiving ste-roids.14,15 Hyperlipidemia5,16 and diabetes are rec-ognized factors in the development of atherosclero-sis.

In case 1 a combination of hypertension, immu-

670 Case reports Annals of Vascular Surgery

nosuppresive therapy, and increased EF may havecontributed to the development of thoracic aneu-rysm. Hypertension, immunosuppresive therapy,hyperlipidemia, and increased EF were present incase 2, and we think that they were involved in therapid growth of the TAAA.

The natural history of TAAA in heart transplantrecipients is not definitively established. Muluk etal. reported three patients with TAAA who died ofacute rupture, and they point out that TAAAs havean apparent propensity to rupture at small sizes.8

This was not the case in our experience, since pa-tient 2 had a 6-cm TAAA at the time of transplan-tation, and a CT scan done 6 months later showedan increase in the transverse diameter of the tho-racic and abdominal aortas, reaching 9 and 7 cm,respectively. With regard to the timing of the op-eration, for those patients with significant aneu-rysms diagnosed before transplantation, Bull et al.recommend that surgical repair he done beforetransplantation.5 In the cases presented here, be-cause of the increased risk of surgical TAAA repairbefore transplantation, we decided to defer the op-eration until after transplantation. Because of theincreased risk of rejection episodes and infection inthe first year after transplantation, surgical repairshould be delayed until the end of the first year. Incase 1, the patient underwent surgical TAAA repairwhen the size exceeded 6 cm, according to ourpractice in nontransplanted patients. In case 2, adecision was made to conduct close clinical and im-aging (ultrasonography) follow-up. Considering therapid growth of the aneurysm, surgical treatmentwas indicated 8 months after transplantation.

Some aspects of perioperative management ofcardiac transplant recipients who undergo this typeof surgical procedure should be emphasized. Preop-erative assessment should include evaluation for re-jection. In our practice, preoperative endomyocar-dial biopsy is not performed if there are no clinicalsigns of congestive heart failure, new onset ofrhythm disturbances, or ischemic abnormalities onelectrocardiogram, or if there is a decreased EF onthransthoracic echocardiogram. If annual coronaryangiography has excluded graft coronary arthero-sclerosis, coronary angiography before operation isnot indicated. Anesthetic agents with myocardialdepressant action are to be avoided.

During the operation, hemodynamic changes re-lated to aortic occlusion and declamping are welltolerated if ventricular function is normal and if anadequate preload is maintained throughout the op-eration. Given these conditions, pulmonary arterycatheterization with a Swan-Ganz catheter is indi-cated.

Careful evaluation of immunosuppresivetherapy is mandatory. Patients taking prednisoneare given small, perioperative increased doses ofcorticosteroids, the dosage of which is then reducedto the maintenance dosage over the next days. Af-ter surgery in the two patients presented here, cy-closporine and azathioprine were administered in-travenously for the first 48 hr and given orallythereafter; however, our actual preference is to ad-minister these agents through the nasogastric tubebegining the day of surgery. Cyclosporine levelsshould be monitored daily to adjust cyclosporinedosage. Prophylactic measures for prevention of in-fections are of prime concern and include perioper-ative antibiotics (usually a cephalosporin), asepsisduring insertion of indwelling catheters (intrave-nous, artery, urinary, and gastric), early postopera-tive removal of invasive lines, wound care, andearly mobilization and vigorous physiotherapy toavoid pulmonary complications. The basic operativetechnique for aneurysmectomy has not been modi-fied in these patients.

In summary, from our limited experience, sev-eral points deserve mention. First, those cardiactransplant recipients with AAA or TAAA prior totransplant must be closely observed for detection ofeither onset or growth of aneurysms. We suggestclinical and physical abdominal examination fol-low-up and routine periodic (every 3 to 6 months)ultrasonographic examination. When expansionbecomes evident or the AA becomes large, a CTscan should be performed. Second, for those pa-tients with significant TAAA diagnosed beforetransplantation and severe myocardial dysfunction,we recommend surgical repair after transplanta-tion. Third, because of the frequent combination offactors that may promote the onset and enlarge-ment of aneurysms (i.e., systemic hypertension, hy-perlipidaemia, diabetes) in heart transplant recipi-ents, careful control of all of these factors is neededon account of the increased expansion rate of an-eurysms in these patients. We suggest that resectionof TAAA in cardiac transplant recipients is feasibleand well tolerated. Further experience in this clini-cal setting is needed.

REFERENCES

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2. Fragomeni LS, Kaye MI. The Registry of the InternationalSociety of Heart Transplantation: fifth official report–1988. JHeart Transplant 1988;7:249-253.

3. Kriett JM, Kaye MP, Parascandola SA, et al. The Registry ofthe International Society of Heart Transplantation: seventh

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4. Reichman W, Dyke C, Lee HM, et al. Symptomatic abdomi-nal aortic aneurysms in long-term survicors of cardiac trans-plantation. J Vasc Surg 1990;11:476-479.

5. Bull DA, Hunter GC, Copeland JG, et al. Peripheral vasculardisease in heart transplant recipients. J Vasc Surg 1992;16:546-553.

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7. Defraigne JO, Sakalihasan N, Demoulin JC, et al. Successfulabdominal aortic aneurysm resection in long-term survivorsof cardiac transplantation. Cardiovasc Surg 1995;3:321-324.

8. Muluk SC, Steed DL, Makaroun MS, et al. Aortic aneurysmin heart transplant recipients. J Vasc Surg 1995;22:689-696.

9. Ammori BJ, Madan M, Bodenham AR, et al. A review of themanagement of abdominal aortic aneurysms in patients fol-lowing cardiac transplantation. Eur J Vasc Endovasc Surg1997;14:185-190.

10. Cronenwett JL, Murphy TF, Zelenock GB, et al. Actuarialanalysis of variables associated with rupture of small ab-dominal aortic aneurysms. Surgery 1985;98:472-483.

11. Slaiby JM, Ricci MA, Hendley ED, Pilcher DB. Expansion ofaortic aneurysms is reduced by propranolol in a hyperten-sive rat model. J Vasc Surg 1994;20:178-183.

12. Gadowski GR, Ricci MA, Hendley ED, et al. Hypertensionaccelerates the growth of experimental aortic aortic aneu-rysms. J Surg Res 1993;54:431-436.

13. Ozdogan E, Banner N, Fitzgerald M, et al. Factors influenc-ing the development of hypertension after heart transplan-tation. J Heart Transplant 1990;9:548-553.

14. Reilly JM, Savage EB, Brophy CM, et al. Hydrocortisonerapidily induces aortic rupture in a genetically susceptiblemouse. Arch Surg 1990;125:707-709.

15. Sato O, Takagi A, Miyata T, et al. Aortic aneurysms in pa-tients with autoimmune disorders treated with corticoste-roids. Eur J Vasc Endovasc Surg 1995;10:366-369.

16. Higgins RM, Ratcliffe PJ. Hypercholesterolemia and vasculardisease after transplantation. Transplant Rev 1991;5:131-149.

672 Case reports Annals of Vascular Surgery