Renovascular hypertension after trauma may develop through several mechanisms: renal arterial stenosis or occlusion, parenchymal compression caused by perinephric hematoma (Page kidney), or chronic scar formation [109, 111, 112]. All of these result in a reduction in renal blood flow, which can then cause a unilateral hypersecretion of renin and resultant hypertension [25]. Diagnosis can be made with selective angiography and renal vein renin levels. Older studies of renal trauma patients show rates of new‐onset hypertension of 4–5%, with onset between two weeks and eight months of injury [80, 112]. A more recent study contradicts these data, showing that patients who develop hypertension after renal trauma typically manifest it during their initial hospitalization and do not develop delayed hypertension during long‐term follow‐up [114].
Management with medications, renal artery bypass surgery, or partial or total nephrectomy has been shown to be effective [109, 111]. In studies evaluating conservative treatment, treatment rates range from 28 to 50% [111, 112, 114, 115]. In terms of surgical management, elevated renin levels from the affected kidney have been shown to predict a good response to surgical treatment [111, 116]. Similarly, one study showed that in cases of arterial stenosis or occlusion, early nephrectomy within the first year after injury had better response rates compared to delayed nephrectomy [108].
Other Complications
Other rare complications may include chronic pyelonephritis, post‐trauma hydronephrosis, stone formation, fistulae, or flank pain [82].
Mortality
Mortality following renal trauma is nearly always related to associated injuries, with estimates of renal trauma driven mortality at less than 0.1% of all deaths [25].
Conclusions
The majority of renal trauma is caused by blunt mechanisms, making it vital for emergency providers and surgeons to have an understanding of renal trauma. Evaluation and management of blunt renal trauma has evolved significantly over the past decade. Guidelines from urologic societies have helped to disseminate indications for imaging and managing high‐grade kidney injuries. Over time, there has been an evolution toward non‐operative management, as data have shown good success with conservative approaches. The goal of diagnosing and managing renal trauma should be to preserve renal function, and this includes appropriate treatment of complications and failed conservative management. Long‐term follow‐up and assessment of renal function in these patients is lacking and requires updating.
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29 29