750 SA MEDICAL JOURNAL VOLUME 64 29 OCTOBER 1983

aneurysm•aortIckidney

Ruptured abdominaland horseshoeA case report

D. F. DU TOIT, H. LOUWRENS, J. KLOMPJE, J. H. GROENEWALD

Summary

A patient with a ruptured abdominal aortic aneurysmassociated with a horseshoe kidney is reported on.The treatment included aneurysmectomy and inser­tion of an aortic Dacron prosthesis without divisionof the isthmus of1he kidney.

The postoperative course was complicated by astroke and mild renal failure, but the patient madeexcellent progress and was discharged from hospital1 month after admission.

S Atr Med J 1983; 64: 750-751.

The anomaly ofa horseshoe kidney is reported to occur in 1/500- 1/1000 autopsies I These malformed kidneys usually functionnormally and are not more predisposed to renal disease thannormal.'

The association ofan abdominal aortic aneurysm (AAA) and ahorseshoe kidney is uncommon.2

.3 This combination is extremely

difficult to diagnose and is often unsuspected. The incidence ofisolated ruptured abdominal aneurysms in association with ahorseshoe kidney is very low.4

-6 The coexistence of a horseshoe

kidney and an AAA presents multiple challenges to the surgeonwhich include correct pre-operative diagnosis, difficult dissectionof the aneurysm, preservation of renal vasculature, inadequateexposure, and difficulty with insertion of the prosthesis.

We report the successful treatment ofa patient who presentedwith a ruptured AAA and an unsuspected horseshoe kidney.

On examination the blood pressure was 170/85 mmHg, thepulse rate 96/min and the haemoglobin value 8 g/dl. A.palpable,pulsatile abdominal mass was noted to the left of the' midline,associated with rebound tenderness. All peripheral pulses werepalpable. Examination of the respiratory and cardiovascularsystems and gastro-intestinal tract was negative.

A clinical diagnosis of rupturtd abdominal aneurysm wasmade and an emergency laparotomy, without aortography orultrasonography of the abdomen, was carried out.

At laparotomy a ruptured infrarenal AAA 8 cm in diameterwas found; the aneurysm was associated with a horseshoe kidneyand was situated anterior to the bifurcation of the aorta.Excessive haemorrhage together with the overlying kidney madedissection and control of bleeding from the aneurysm extremelydifficult. The left renal artery was normal; the right renal arteryoriginated from the right common iliac artery and entered theisthmus of the kidney. Both renal veins emerged from the upperpoles of the kidney and joined the inferior vena cava below thediaphragm. Two ureters crossing the anterior surface of thekidney were identified. The isthmus of the kidney was 1,0 - 1,5cm thick and consisted of functioning parenchymal tissue. Afterproximal control of the aneurysm had been achieved theaneurysm was resected and replaced with a 22 x 10 cm wovenDacron aortic bifurcation graft, without division of the isthmusof the kidney. The graft was placed behind the kidney. Theaneurysm had eroded the lumbar vertebra and had ruptured onthe left posterolateral aspect.

Intra-operative blood loss was in excess of 8 litres. The patientwas anuric for 5 hours but started excreting after an infusion of20% mannitol. He sustained a right-sided hemiparesis because ofa cerebrovascular accident on the 5th postoperative day butrecovered partially and was discharged I month after resection ofthe aneurysm with residual paresis of the right leg. Mild renalfailure was managed without need for dialysis.

Case report

A 59-year-old White man was referred from a peripheral hospitalto Tygerberg Hospital because ofan acute abdomen. Apart frommild hypertension, for which he had been receiving treatmentfor 2 months, he had had no previous illnesses of note.

The present history included a sudden onset of excruciatingabdommal pain localized to the left iliac fossa, pain in the lumbarregion and perineum and syncope, which had been present for 12hours before admission.

Department of Surgery (Division of Vascular Surgery),University of StelIenbosch and Tygerberg Hospital, Parow­valIei, CPD. F. DU TOIT, PH.D., F.RC.S., Senior SurgeonH. LOUWRENS, M.8. cRR,RegistrarJ. KLOMPJE, M.R CH.R,RegistrarJ. H. GROENEWALD, M.MED.,Principal Surgeon

Reprint requests to: Or D. F. du Toit, Depr of Surgery, University of Stellenbosch MedicalSchool, PO Box 63, Tygerberg, 7505 RSA.

Discussion

The contemplated resection of an AAA in association with ahorseshoe kidney poses special problems to the surgeon whichinclude preservation of renal blood supply and renal function inaddition to problems related to the fused kidney. In elective casesthe resectability of the aneurysm is determined entirely by theblood supply of the kidney. Besides aortography, intravenouspyelography is of vital importance in planning the operativeapproach. The vessels supplying a horseshoe kidney may arise atany point along the aorta, occasionally from the iliac arteries, asin our case; or from the mesenteric vessels. 2 In many cases theaneurysm is irresectable if the major renal vessels arise from it. Inaddition, if multiple small vessels enter the aneurysm the latter isconsidered inoperable.

The management of the isthmus of the kidney is controversial.Some workers2

•3 have advocated simple division of the isthmus

with oversewing of the cut surfaces, which facilitates resection ofthe aneurysm and placement of the prosthesis. Unfortunately, acomplicated vascular pattern and a functioning isthmus are

likely to coexist. The outcome of division of the isthmus in thesecases is unpredictable. Under these circumstances resection ofthe aneurysm may be possible if the graft is placed posteriorly, asin our patient. A second alternative is autotransplantation of thekidney, but there is no recorded instance in ~he literature ofsuccessful autotransplantation of a horseshoe kidney followingresecti.on of a ruptured AAA.

Division of the isthmus of the kidney is not without danger.Firstly, damage to the renal pelvis as a result of surgicalmanipUlation may produce spillage of infected urine whichexposes the patient to the serious sequelae ofan infected vascularprosthesis. Secondly, division of the isthmus or an associatedpolar artery may result in infarction of renal tissue. 5 Cayten eral. 4 have suggested that the isthmus should only be divided whenextended exposure is mandatory. Perhaps division of the isthmusshould be strongly considered in ruptured aneurysms so as tofacilitate control of bleeding fr9m the aneurysm. They indicatethat in elective cases it is frequently possible to mobilize thekidney and place the graft on the posterior aspect of the isthmus.They also point out that anomalous venous drainage is commonin the presence of a horseshoe kidney, necessitating great carebefore unidentified vessels are ligated.

SA MEDIESE TYDSKRIF DEEL 64 29 OKTOBER 1983 751

Rupture or threatened rupture of an AAA in the presence ofahorseshoe kidney is a life-threatening situation and the survivalof the patient is at stake. Fortunately the entity is rare, but heroicsurgical manoeuvres may be required to save the patient.

We thank Professor L. C. J. van Rensburg for his advice, Mrs VanDalen for typing the manuscript, and Dr C. de W. Vivier, MedicalSuperintendent of Tygerberg Hospital, for permission [0 publish.

REFERENCES

I. Robbins SL, Cotran RS. Pathologic Basis of Disease. 2nd ed. Philadelphia: WBSaund<rs, 1979: 1123.

2. Bietz OS, Merendino KA. Abdominal aneurysm and horseshoe kidney: areview. Ann SlIrg 1975; 181: 333-341.

3. Brown OW, Oosick SM, Blakemore WS. Abdominal aortic aneurysm andhorseshoe kidney: a different perspective. Arch SlIrg 1979; 114: 860-861.

4. Cayten CG, Davis AV, Berkowitz HO, Roberts B. Ruptured abdominal aorticaneurysms in the presence of horseshoe kidneys. SlIrg Gynecol Obstet 1972; 135:945-949.

5. Landes RG, Trumbell HR, Nicoleff OM. Abdominal aortic aneurysm withrupture into the inferior vena cava associated with horseshoe kidney. A,m Surg1978; 187: 329-331.

6. Mannick JA, Brooks JW, Bosher LH, Hume OM. Ruprured aneurysm of theabdominal aorta. N Engl J Med 1964; 271: 915-920.

Carbon monoxide • •pOIsonIngReport of a case with I-year computed tomographic follow-up

DIANNE B. MENDELSOHN, Y. HERTZANU

Summary

A case of acute carbon monoxide poisoning with1-year computed tomographic follow-up is pre­sented. The typical initial bilateral symmetrical low­density areas in the basal ganglia were found tohave.decreased markedly in size in the latter scan.These appearances coincided with th.e initial earlyoedematous phase of infarction ending in the latepermanent necrotic stage.

S AIr Med J 1983; 64: 751-752.

Hypoxia resulting from carbon monoxide (CO) poisoning is dueto the displacement of oxygen (02) from haemoglobin. COcompetes with O2 by diffusing across alveolar membranes andbinding to haemoglobin. Haemoglobin has approximately 250

Department ofDiagnostic Radiology,Johannesburg Hospitaland University of the Witwatersrand, JohannesburgDIANNE B. MENDELSOHN, M.B. B.CH., F.F.RAD. (D.) (SA)

Y. HERTZANU, M.D. (YASSI)

Reprint requests [Q: Dr D. B. Mendelsohn, Dep( of Diagnostic Radiology, JohannesburgHospital. Private Bag X39. Johannesburg, 2000 RSA.

times the affinity for CO that O2 has, and exposure to smallconcentrations of CO may therefore be clinically significant.Although all organs are affected by CO poisoning, the brain isthe most important of these. Pathologically there is markedvenous and capillary dilation. Petechial haemorrhages andfrequently early necrosis of the basal ganglia, most often theglobus pallidus as well as the reticular zone of the substantianigra, have been observed. The Purkinje cells of the cerebellarcortex and dentate nucleus are commonly involved, as arecortical cells. I

Case report

A26-year-old man who attempted suicide by gassing himself in amotor vehicle was admitted to an outlying hospital in a confusedstuporous state. He regained consciousness a day later and wastransferred to our hospital. On examination he was disorientatedfor time and place with marked memory impairment and amask-like facies. There were no extrapyramidal signs. Gene­ralized brisk reflexes were present. The neurological examinationwas otherwise negative. Computed tomography (CT) showedbilateral symmetrical low-density areas in the globus pallidus.There was no change following intravenous contrast admini­stration (Fig. I). The patient was discharged shortly thereafterand followed up as an outpatient. One year later he againunderwent scanning owing to persistent poor memory andinability to concentrate. CT showed a marked diminution in the