Surgical Treatment of Renovascular Hypertension in Children

Jonathan L. Eliason and James C. Stanley

Renal artery occlusive disease affecting pediatric patients is an important but very uncommon cause of hypertension in children. Renal artery stenoses in this age group represent a wide spectrum of heterogeneous diseases, although developmental anomalies with concomitant narrowings of the splanchnic arteries and the abdominal aorta itself are most common. Inflammatory aortoarteritis is the second most common cause of renal artery stenoses in children, and in South America and Asia it is a more commonly encountered form of renovascular disease.

Pediatric renovascular hypertension when unrecognized and untreated has been associated with serious complications including hemorrhagic stroke, hypertensive encephalopathy with impaired mental development, and failure to thrive. Poorly controlled hypertension in these children often results in left ventricular hypertrophy and severe diastolic dysfunction. Additionally, when the entire renal mass is involved, flash pulmonary edema associated with renal insufficiency can occur.

Operative Therapy

Arterial reconstructive surgery for pediatric renovascular hypertension must be individualized, taking into account the patient’s anatomic renal artery disease, as well as concomitant aortic and splanchnic arterial disease.

Types of Surgery

Renal Artery Implantation

Implantation of the normal renal artery beyond an ostial stenosis has become an important means of pediatric renal revascularization. In these circumstances, the transected renal artery should be spatulated anteriorly and posteriorly to create a generous anastomotic orifice. An oval aortotomy can be best made with an aortic punch, being a little more than twice the diameter of the renal artery being implanted. This provides a sufficiently large anastomosis, so as the child grows an anastomotic narrowing will not evolve.

The aortorenal anastomoses should usually be performed using interrupted monofilament sutures. However, a continuous suture may be used in older adolescents with large renal arteries. Most implantations of the renal artery will be into a normal infrarenal segment of the aorta (Figure 1). Medial mobilization of the kidney may be necessary to ensure that there is no tension on the implanted renal artery.

FIGURE 1 Bilateral renal artery aortic implantations. Note the remnant proximal arteries at their aortic origins. (From Stanley JC, Zelenock GB, Messina LM, et al: Pediatric renovascular hypertension: A thirty-year experience of operative treatment, *J Vasc Surg* 21:212–227, 1995.)

A renal artery branch or accessory renal artery beyond its stenotic segment may also be implanted into a nondiseased adjacent main or segmental renal artery. This also involves spatulation of the segmental vessel and completion of the anastomosis using monofilament sutures (Figure 2). A renal artery may be implanted into the superior mesenteric artery when implantation elsewhere is deemed hazardous.

FIGURE 2 Reimplantation of segmental renal artery, beyond its stenosis, into adjacent segmental renal artery. A, Preoperative arteriogram documenting stenosis and poststenotic dilation *(arrow).* B, Postoperative arteriogram demonstrates widely patent anastomosis *(arrow).* (From Stanley JC, Zelenock GB, Messina LM, et al: Pediatric renovascular hypertension: A thirty-year experience of operative treatment, *J Vasc Surg* 21:212–227, 1995.)

The internal iliac artery is favored as a conduit when a pediatric renal bypass is undertaken (Figure 3). The excised internal iliac artery usually includes its distal branches, which are incised to create a large common orifice for the aortic anastomosis. The distal renal artery–to–iliac artery graft anastomoses should be completed following spatulation of both the iliac artery and renal artery to increase the anastomotic circumference. Such an ovoid anastomosis is less likely to develop a late stricture. In very young children with small arteries, the anastomoses should be completed with interrupted sutures, although a continuous suture may be used in reconstructing larger renal arteries. Stenoses of multiple small renal arteries can require approximation of these vessels to each other to form a larger common orifice to which an aortorenal graft can be anastomosed.