LETTERS TO THE EDITORS The Editors invite readers to submit letters commenting on the contents of articles that appear in the JOURNAL.Also welcome are brief communications in letter form reporting investigative or clinical observations without extensive documentation and with brief bibliography (five titles or less), not requiring peer review but open to critique by readers. Letters to the Editors should be no more than 500 words in length and they may have to be edited for publication.
Ruptured abdominal aortic aneurysms: A new perspective To the Editors:
Two years ago we observed an unexpected phenomenon in two patients with free intraperitoneal rupture (without a retroperitoneal hematoma) of infrarenal aortic aneurysms. In both these patients,.after the loss of 1.5 to 2 L blood in the peritoneal cavity, there was spontaneous tamponade of the torn aortic wall. The opening was sealed off by a large organized thrombus (Fig. 1) in the frst patient and by the small bowel mesentery in the second. This eliminated the need for rapid aortic control and placed the patients in a lesser risk category than the usual patient with free rupture. On reviewing the literature we were unable to find any previous reports of this variation of the pathologic condition. However, we discovered some glaring discrepancies between our current knowledge of different types of rupture and the 'methods of reporting the experience in treating them. Most reports group ruptured aneurysms as a single entity, ignoring the differences in diagnosis, management, and prognosis based on variations in the basic pathologic condition. These variations are well described in every textbook on the subject. For example, the clinical implica-
tions of contained retroperitoneal hematoma, free intraperitoneal rupture, and aortovenous fistul~ are quite different. Tamponade by the posterior peritoneum allows many patients to reach the hospital in time for a life saving operation. The peritoneal cavity offers little or no resistance to hemorrhage; therefore free rupture is very often fatal. 1 Rupture into the venous system essentially results in "autotransfusion" without extravasation. Operations for this type of rupture are elective and do not have the challenge and dangers of obtaining immediate aortic control on opening the abdomen. H o w can we fail to consider this when we report our experience? The obvious solution would be to devise a pathologic classification so that appropriate comparisons can be made. The only attempt at devising a classification, 2 based on the size and location of the hematoma, was found to be impractical, s Another striking defect is the practice of including only operated cases in the reports. This is clearly unjustifiable for a condition in which patients may die in transit or in the hospital because of delays in diagnosis and treatment. If unoperated cases are excluded, the mortality rate for rupture into the duodenum would be 40% instead of the true figure of 82%.4 Similar views have been expressed by others in the past? These issues are particularly important at a time when
Fig. 1. Photograph on opening abdomen in case 1 shows irregularly shaped 12.5 cm aneurysm. Despite the extensive area of rupture offthe aortic wall and peritoneum, bleeding has been tamponaded by large organized thrombus. 661
Journal of VASCULAR SURGERY
Letters to the Editors
Fig. 2. Schematic oblique view ofaortic aneurysm iUusttates proposed classification ofrupture (types I to IV, Table I). DUOD., Duodenum; RLRV, retroaortic left renal vein; LRA, left renal artery;/VC, inferior vena cava; AL, aortic lumen; OT, organized thrombus; RH, retroperitoneal hematoma; P, posterior peritoneum. See Table I for types of rupture.
Table I. Proposed pathologic classification
of ruptured abdominal aortic aneurysms Type of
Description Primary free intraperitoneal rupture (a) Without tamponade (at site of rupture) (b) With spontaneous tamponade Retroperitoneal hematoma (a) Acute (b) Acute with secondary intraperitoneal rupture (c) Chronic Aortovenous fistula (a) Inferior vena cava (b) Left renal vein (c) Iliac vein (not depicted in Fig. 2) Rupture into the gastrointestinal tract
efforts are being made to improve reporting standards and to determine which individuals and institutions should perform major vascular surgery. In view of the above considerations, we would like to propose a pathologic classification for ruptured aneurysms (Table I and Fig. 2). The combination of preoperative data and findings at operation or autopsy will permit accurate categorization in most patients. Reporting known risk factors such as shock and preoperative renal failure, including unoperated cases, and making use of this classification should result in more accurate comparison of reports from different institutions. Kumar IL Patel, 214D
Chief, Vascular Surgery Metropolitan Hospital Center 1901 First Ave. New York, NY 10029
REFERENCES 1. HoUier LH, Rutherford RB. Infrarenal aortic aneurysms. In: Rutherford RB, ed. Vascular surgery. 3rd ed. Philadelphia: W B Saunders, 1989:919-20. 2. Fitzgerald JF, Stitlman RM, Powers JC. A suggested classification and reappraisal of mortality statistics for ruptured atherosclerotic infrarenal aortic aneurysms. Surg Gyneco! Obstet 1978;146:344-6. 3. Hoffman M, Avellone JC, Plecha FR, et al. Operation for ruptured abdominal aortic aneurysm: a community-wide experience. Surgery 1982;91:597-602. 4. Sweeney MS, Gadacz TR. Primary aortoduodenal fistula: manifestation, diagnosis, and treatment. Surgery 1984;96: 492-7. 5. Rutherford RB, McCroskey BL. Ruptured abdominal aortic aneurysms. Special considerations. Surg Clin North Am 1989;69:859-68. 24141/37386
Inflammatory abdominal aortic aneurysm and the associated T cell reaction: A case study To the Editors: The article by Leiberman et al. (J VAsc SURG 1992;15:569-72) clearly demonstrates the chronic nature of the inflammatory infiltrate in the arterial wall in inflammatory abdominal aortic aneurysms (IAAA). Immunohistologlc analysis of the tissue from their patient revealed the presence of activated T cells with a mixture of helper/inducer ( C D 4 + ) and suppressor/cytotoxic (CD8) cells. Interestingly, this pattern of inflammatory cells is found in all abdominal aortic aneurysms (AAA)) 4 The inflammatory cells are predominantly localized in the outer