View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Eur J Vasc Endovasc Surg 18, 96±104 (1999) Article No. ejvs.1998.0786 Morphology of Ruptured Abdominal Aortic Aneurysms J. Golledge∗, J. Abrokwah, K. N. Shenoy and R. H. Armour Department of Surgery, The Lister Hospital, Corey's Mill Lane, Stevenage SG1 4AB, U.K. Objectives: it has been suspected that the position at which aneurysm rupture occurs would affect outcome. The aim of this prospective study was to relate the morphology of the ruptured abdominal aortic aneurysm (RAAA) to the clinical characteristics and outcome of the patient. Design, patients and methods: over a ®ve-year period 46 patients with RAAAs (11 identi®ed at operation and 35 at post-mortem (PM)) were examined to identify the number and site of aneurysm rupture, the characteristics of the aneurysm (site, shape, length, diameter and associated iliac aneurysm) and the presence and site of retroperitoneal or intraperitoneal haematoma. The patients were also assessed for a range of associated medical conditions. Univariate analysis was used to identify variables predicting the site of aneurysm rupture and survival following rupture. Results: most aneurysm ruptures (73%) occurred in the middle third where the aneurysm diameter was greatest. Relatively few ruptures (13%) were in the left posterior quadrant of the aneurysm. A history of chronic lung disease (p=0.04) signi®cantly predicted the quadrant of aneurysm rupture, while a history of carcinoma (p=0.02) predicted the level of rupture. Nine of the 46 (20%) patients survived. Survival was predicted by the transverse site of rupture (p=0.0004) and the absence of ischaemic heart disease (p=0.02). Conclusion: these data suggest that the site of aneurysm rupture, which may be in part predicted by the clinical characteristics of the patient, in¯uences outcome. Key Words: Aortic aneurysm; Rupture; Site. Introduction and therefore survival. In this study we have assessed the importance of the rupture site of abdominal aortic At present, there is disagreement about which patients aneurysms. should be selected for elective abdominal aortic an- eurysm repair, and the results of the small aneurysm trial are awaited with interest.1,2 Further understanding of the mechanisms leading to rupture of abdominal Methods aortic aneurysms would enable better selection of patients for endovascular or open repair and identify Over a ®ve-year period, patients were recruited from possible therapeutic targets for the medical control of two sources: Firstly ruptured abdominal aortic an- aneurysm rupture. Aneurysm rupture occurs at the eurysms (RAA) undergoing surgical intervention site at which the stress exerted on the wall from within (n=11), and secondly all similar cases identi®ed at overcomes the ability of the wall to resist these forces. post-mortem (PM) examination (n=35). Clearly there Aortic wall stress is dependent on a complex relation- would have been other patients who died suddenly ship between aortic pressure and wall thickness.3,4 in the area, where the diagnosis of abdominal aortic While the aortic wall strength is determined by the aneurysm was not suspected and who did not undergo elastin and collagen content.5±8 Thus the site of an- post-mortem examination. Of the 35 post-mortem eurysm rupture could give important clues on the cases, 12 patients died suddenly at home, eight had process of rupture. In addition, rupture site might clear preceding symptoms but failed to seek medical determine the likelihood of free intraperitoneal rupture help, four reached hospital but failed to be resuscitated, four patients were felt unsuitable for operation, three ∗ Please address all correspondence to: J. Golledge, 35 Sullivans died during transit (two from home to The Lister and Reach, Walton on Thames, Surrey, London KT12 2QB, U.K. one during transfer to another hospital), three were 1078±5884/99/080096+09 $12.00/0 1999 W.B. Saunders Company Ltd. Morphology of Ruptured Abdominal Aortic Aneurysms 97 admitted to hospital and died without the correct Table 1. Site of rupture along abdominal aortic aneurysm. diagnosis being made and one patient died in the operating theatre (following anaesthetic induction Site of rupture Operative cases PM cases Total prior to laparotomy). For these patients the median Upper third 4 3 7 time from symptoms to death was 2 hours, range Middle third 7 28 35 Lower third 0 6 6 0±330 hours. Eleven cases were excluded for the following reasons: inability to identify the site of rupture at operation (n=6, three survived and were discharged home and three died within 30 days), transfer to Results another hospital (n=3), ruptured thoracoabdominal aneurysm (n=1) and ruptured non-aneurysmal aorta The median age of the patients was 73.5 (range 60±93) (n=1). Local ethical approval was obtained. Operative years with the majority being male (40 of 46). The and post-mortem specimens were examined to identify incidence of associated disease was as follows: the following: the site of the aneurysm rupture in ischaemic heart disease (31%), hypertension (37%), the transverse (recorded as 1 to 12 o'clock and later cerebrovascular disease (13%), chronic obstructive air- categorised as right or left anterior or posterior quad- way disease (13%), renal failure (11%), carcinoma (9%; rant) and longitudinal (upper, middle or lower third) bronchial carcinoma 2, colonic carcinoma 1, jejunal dimensions; the number and length of ruptures; the carcinoma 1), diabetes mellitus (7%) and liver cirrhosis presence and principal position (right, central, left or (2%). pelvic) of retroperitoneal haematoma; the presence and volume of intraperitoneal haematoma; the pres- ence of aortocaval or aortogastrointestinal ®stulae; the shape (fusiform, saccular or hourglass), site Characteristics of abdominal aortic aneurysm and rupture (infrarenal, juxtarenal or suprarenal), length and diameter of abdominal aortic aneurysm (by calliper Most aneurysms were infrarenal (40, 87%), four were measurement); the presence and characteristics of juxtarenal (9%), and two were suprarenal (4%). Ninety- associated iliac aneurysms. The following factors six per cent of aneurysms (44) were fusiform, one was saccular and one hourglass in shape. All aneurysms were also identi®ed by a combination of history, measured 5 cm or more in transverse diameter, the clinical examination, blood tests and examinations median diameter was 9 cm (range 5±14 cm). The me- performed at PM: age, gender, ischaemic heart dian aneurysm length was 11 cm, range 7.5±18 cm. In disease (history, ECG or PM evidence of myocardial two cases (one identi®ed at operation and one at PM) infarction), hypertension (systolic BP>180 mmHg, there were two sites of aneurysm rupture; in these diastolic BP>100 mmHg or ECG/PM evidence of patients, the principal site of rupture was taken as the left ventricular hypertrophy), renal failure (serum larger. In all other cases (96%) there was one site creatine>120), diabetes mellitus, cerebrovascular of rupture. The position of these 48 ruptures in the disease (previous stroke or TIA), previous or recent longitudinal and transverse dimensions are shown in carcinoma, liver cirrhosis, chronic lung disease (em- Table 1 and Fig. 1. Most ruptures were in the middle physema, chronic bronchitis or bronchiectasis; diag- third of the aneurysm (73%), while in the transverse nosed by history or PM examination of lungs), time dimension ruptures were distributed all around the from symptoms to death. Outcome was de®ned as circumference of the aneurysm, with relatively few survival for those patients undergoing successful op- ruptures in the left posterior quadrant (Fig. 1). Sur- erations and being discharged home well, or death for prisingly, most ruptures identi®ed at operation (46%) those patients having unsuccessful operation or whose were in the left posterior quadrant. aneurysms were identi®ed only at PM. Data was stored prospectively on record cards and later transferred to a computer spreadsheet (Microsoft Excell, Microsoft Limited, Reading, U.K.) and statistical Retroperitoneal and intraperitoneal haematoma and program (Statview, Abacus Concepts, Berkeley, CA, relation to rupture site U.S.A.). Univariate (Chi-squared with Yates correction, Mann±Whitney U-test and Kruskal±Wallis test) ana- All except one of the patients had a huge retro- lysis was used to identify variables predicting the site peritoneal haematoma while only 19 (41%) had intra- of aneurysm rupture and survival. peritoneal blood (in nine of these 19 cases this was Eur J Vasc Endovasc Surg Vol 18, August 1999 98 J. Golledge et al. Fig. 1. The distribution of rupture sites in the transverse dimension for 46 abdominal aortic aneurysms. In two cases there were two sites of rupture. Shown are numbers for PM (®rst number) and operative cases. blood-stained ¯uid rather than frank blood). The one transverse dimension and the position of the retro- patient with no retroperitoneal or intraperitoneal peritoneal haematoma, p=0.0001 (Table 2). haematoma had an aortocaval ®stula. Intraperitoneal bleeding was identi®ed in seven of 11 patients (64%) undergoing operation compared to 12 of 35 (34%) aneurysms identi®ed at PM, p=0.04. Table 2 shows Factors associated with the site of aneurysm rupture the principal site of the retroperitoneal haematoma as (Table 3) right abdominal (54%), central (7%), left abdominal (35%) or pelvic (2%). There was a very close re- Table 3 presents the clinical characteristics and the lationship between the site of aneurysm rupture in the aneurysm morphology for patients according to the Eur J Vasc Endovasc Surg Vol 18, August 1999 Morphology of Ruptured Abdominal Aortic Aneurysms 99 Table 2. Relationship between site of rupture and retroperitoneal haematoma. Position of retroperitoneal haematoma Right Left Central Pelvic None Site of rupture Right anterior 11 4 0 1 0 Right posterior 12 0 1 0 1 Left anterior 2 8 2 0 0 Left posterior 0 4 0 0 0 Total 25 16 3 1 1 Site of rupture predicted position of retroperitoneal haematoma, p=0.0001 by Chi-squared.