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Journal of Postgraduate Medicine, Vol. 55, No. 2, April-June, 2009, pp. 124-126 Case Report Spontaneous closure of a traumatic intrarenal pseudoaneurysm Madhusudhan KS, Sharma S, Seth A Department of Radiodiagnosis, All India Institute of Medical Sciences, New Delhi - 110 029 Date of Submission: 18-Apr-2008 Code Number: jp09033 PMID: 19550058 Abstract Renal artery pseudoaneurysms caused by blunt abdominal trauma are uncommon. It requires treatment with angioembolization because of high risk of rupture. Spontaneous closure of the pseudoaneurysm is extremely unusual. We report a case of a 29-year-old male who developed a traumatic intrarenal pseudoaneurysm that later resolved spontaneously. This report provides an insight into the natural history of renal pseudoaneurysm and suggests a potential option of managing them conservatively.Keywords: Blunt abdominal trauma, pseudoaneurysm, spontaneous resolution Renal pseudoaneurysm is an uncommon complication after abdominal trauma. They are generally seen with penetrating trauma. [1] Iatrogenic renovascular injury is a well recognized complication; most of these lesions close spontaneously. [2] Pseudoaneurysm developing after blunt abdominal trauma is however uncommon. If left untreated, they tend to rupture, causing life-threatening hemorrhage. [3],[4] Spontaneous resolution of an intrarenal pseudoaneurysm after blunt trauma is extremely rare with only two cases reported in English literature. [5],[6] We report a case of spontaneous resolution of an intrarenal pseudoaneurysm developing after a blunt abdominal trauma. Case Report A 29-year-old male presented to the emergency department at a peripheral hospital with a history of motor vehicle accident and gross hematuria. Local examination showed a bruised left flank. His haemodynamic parameters revealed a blood pressure of 102/66 mm of Hg and pulse rate of 95/min. He was given one unit of blood followed by intravenous fluids. His renal parameters showed serum creatinine of 0.8 mg/dL and blood urea of 23 mg/dL. Contrast enhanced computed tomography (CT) scan [Figure - 1] showed complete transection in the mid part of left kidney with a large perinephric hematoma. There was no apparent vascular injury demonstrated and the pelvicalyceal system appeared normal. The renal injury score was 3 (American Association of the Surgery of Trauma - AAST). The remaining abdominal organs were normal. The patient was managed conservatively with intravenous fluids. His blood pressure increased to 112/74 mm of Hg the next day. As he had hematuria, another unit of blood was transfused. Intravenous fluids were given 8 hourly for another two days. His haematuria disappeared after nine days. He remained stable and was discharged. His blood pressure at the time of discharge was 124/82 mm of Hg. Two months later, he again presented to the emergency department with a two-day history of increasing left flank pain. There was no haematuria. Clinical examination and laboratory parameters were unremarkable (hemoglobin - 13.2 g/dL, serum creatinine - 1.1 mg/dL, and blood urea - 28 mg/dL). Subsequently, CT scan showed a 4.8 x 3.4 cm sized intra renal pseudoaneurysm [Figure - 2] with partial thrombosis within the left kidney. The patient was then referred to us for further management. Color Doppler sonography done eight days after last CT again showed a peripherally thrombosed pseudoaneurysm. Its central part showing a characteristic swirling flow was now smaller in size when compared to CT scan. The patient′s coagulation profile including prothrombin time (13 sec against control value of 11.5 sec) and international normalized ratio (INR = 1.2) was normal. Digital Subtraction Angiography (DSA) was then undertaken with a view for selective embolization. It showed the pseudoaneurysm arising from the upper polar segmental artery with a narrow neck [Figure - 3]. The vascular anatomy was found to be quite tortuous for embolizing with standard 5F catheters available. Due to the immediate non-availability of the microcatheters and microcoils, embolization was deferred. A week later, with the required materials handy, a repeat elective DSA was done but showed no pseudoaneurysm [Figure - 4]. It had completely thrombosed spontaneously. The patient was observed for next 48 hours within the hospital and then discharged. Discussion Intrarenal pseudoaneurysm after blunt abdominal trauma is rarely seen. It develops as a result of sheering arterial injury caused by strong deceleration forces. [1] During the stage of acute injury, the presence of hypotension, development of clot and the tamponade by surrounding renal parenchyma temporarily occlude the injured artery. Subsequently, fluid replacement restores the blood pressure, the clot degrades, and the surrounding tissue shrinks due to necrosis. This results in formation of a communication between the intravascular and extravascular spaces leading to the development of pseudoaneurysm. [7] The most common presentation of renal pseudoaneurysm is haematuria. Other symptoms include flank pain, mass, hypertension or abdominal bruit. [8] The time to presentation is variable and could range from one day to 15 years. [3],[8] Imaging plays an important role in demonstration of renal vascular injuries in suspected patients. Color Doppler sonography is a useful bedside modality in unstable patients to show vascular abnormalities and pseudoaneurysm. It shows turbulent flow within the pseudoaneurysm and to-and-fro motion at its neck. Contrast enhanced CT scan done in arterial, venous and delayed phase allow imaging of the entire urinary tract and is useful in stable patients. [8] It shows the lesion enhancing as much as the adjacent artery in all three phases. Angiography is useful, as it not only, confirms the presence of a pseudoaneurysm seen as a round or oval structure opacifying from main or segmental renal artery or its branches but also enables elective embolization in the same sitting. Once a pseudoaneurysm is formed, it is maintained by the high pressure from the lacerated renal artery and may eventually rupture, with erosion into the pelvicalyceal system or surrounding tissues causing life-threatening haemorrhage. [4],[7] Angiographic embolization is considered to be the treatment of choice for intrarenal pseudoaneurysms. [9],[10] Its advantages over surgery include maximal preservation of functional renal parenchyma, use on patients with solitary or transplanted kidneys, and reduced morbidity and mortality. A low pressure must be used, as pseudoaneurysms have no true wall. Embolization has been done using coils, gelfoam, polyvinyl alcohol and n-butyl cyanacrylate. [11] Surgery may be required when pseudoaneurysm involves main renal artery and in patients who remain haemodynamically unstable despite embolization. [3],[8] A partial or total nephrectomy is usually done in such patients. In the literature, there is paucity of information on the natural course of a post-traumatic renal pseudoaneurysm. The available evidence recommends either embolization or surgery as the treatment for intrarenal pseudoaneurysm due to its high risk of rupture. [8],[9],[11] Spontaneous resolution, as was seen in our case, could be one of the hitherto less described natural outcomes of an intrarenal pseudoaneurysm. This has been reported by other authors too. [5],[6] Also, the present case showed a progressive reduction in the size of the pseudoaneurysm with time. This could possibly suggest a conservative option of managing intrarenal pseudoaneurysms developing after a blunt abdominal trauma, especially when there is no significant hematuria. We feel that these patients must be followed up clinically and radiologically with serial color Doppler ultrasonography to look for any change in size and internal architecture of the pseudoaneurysm. Reduction in its size or increasing internal thrombus may suggest the beginning of the healing process. Severe physical activity must also be avoided. We also suggest not to use NSAIDs when such a conservative approach is planned as they may delay the thrombosis. However, patient′s haemodynamic profile is more important and must take precedence over the sonographic appearance while managing such patients owing to high risk of rupture. The decision of conservative management is nonetheless a difficult one, as embolization, though minimally invasive, is known to be safe and beneficial whilst the risk of aneurysm rupture is life threatening. In line with the established thinking, embolization must always be actively considered if patient develops gross hematuria or shows no signs of pseudoaneurysm thrombosis. The duration up to which the pseudoaneurysm needs to be followed up is difficult to predict and may be dictated by its initial size, its neck, patient′s coagulation profile, and blood pressure. A noninvasive imaging follow-up by color Doppler ultrasound, every couple of days or sooner if clinically indicated, appears to be reasonable. Following complete thrombosis of the pseudoaneurysm, follow up color Doppler ultrasonography may be done after a month or so to look for complete organization of the lesion. Till the first follow up, severe physical activity may be restricted to allow the thrombosis to organize. Further follow up is needed only if the patient is symptomatic. Based on our single case experience and limited support from the available literature we do not recommend the conservative management of intrarenal pseudoaneurysms given the high risk of rupture, but state that the spontaneous thrombosis of intrarenal pseudoaneurysms does occur and may be a feasible option in selected cases. References
Copyright 2009 - Journal of Postgraduate Medicine The following images related to this document are available:Photo images[jp09033f2.jpg] [jp09033f3.jpg] [jp09033f4.jpg] [jp09033f1.jpg] |
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