Technical considerations in the surgical management of renovascular hypertension in children

Blunt femoropopliteal trauma in a child: Is stenting a good option?

Vascular injuries resulting from blunt trauma are uncommon in the pediatric age. In children, there are particular factors that should be taken into account when vascular traumatic lesions are treated: small vessel size or vessel spasm, a higher risk of infection, a tendency for restenosis, and rapid body growth. The endovascular procedure is a minimally invasive, quick technique that restores blood flow immediately. The stent's fate is the Achille's heel of this technique; this is the reason why a careful follow-up and further studies are required.

Improved results of vascular reconstruction in pediatric and young adult patients with renovascular hypertension

From 1955 to 1988, 56 patients 21 years old or younger underwent surgical treatment for renovascular hypertension at our clinic. The cause of renal artery disease was fibrous dysplasia in 53 patients, Takayasu's arteritis in 2 or an arterial aneurysm in 1. Bilateral or branch renal artery disease, and extrarenal arterial disease were present in 16, 23 and 11 patients, respectively. The results of 28 patients treated from 1955 to 1977 (group 1) were compared to those of 28 patients treated from 1978 to 1988 (group 2). Hypertension was cured or improved postoperatively in 83% of the patients from group 1 and in 96% from group 2 (p = 0.07). However, this outcome was achieved through surgical revascularization in only 48% of the patients from group 1 compared to 96% from group 2 (p = 0.0002). A multivariate analysis revealed that the only significant variable related to clinical outcome was the era of treatment, which reflects the improved technical efficacy of revascularization during the last decade. Aortorenal bypass and renal autotransplantation have emerged as the preferred revascularization operations. It currently is possible to achieve amelioration of hypertension and preservation of renal function in most young patients with renal artery disease.

Early diagnosis and management of renovascular hypertension

Renovascular hypertension is more common in hypertensive children than in hypertensive adults, and renal artery stenosis is second only to coarctation of the thoracic aorta as a cause of surgically correctable hypertension. Three infants presented with uncontrollable hypertension secondary to renal artery thrombosis due to umbilical artery catheterization for respiratory distress in the neonatal period. They all responded to nephrectomy. A fourth infant had stenosis of a polar vessel secondary to umbilical artery catheterization and was cured by partial nephrectomy. Two infants with renal artery stenosis secondary to fibromuscular dysplasia benefited from revascularization and, at last follow-up, were normotensive and off all blood pressure medication. Ultrasonography, isotope scanning, angiography and selective renal vein renin assays should be used to identify patients with surgically correctable lesions. The use of fine suture material and microvascular surgical techniques, including ex vivo revascularization and autotransplantation, can salvage renal parenchyma and relieve hypertension. Infants with less than 10 percent renal function on the involved side should have a nephrectomy. The infant with an umbilical arterial catheterization line needs blood pressure monitoring and aggressive evaluation and treatment of persistent hypertension.

Technical consideration in management of renovascular hypertension in an infant with double renal arteries

Renovascular hypertension is a curable disease that has recently been recognized with increasing frequency. A renal scan in a 1-month-old hypertensive white male showed diminished function of the right kidney, and his peripheral vein renin was elevated. Multiple antihypertensive medications failed to control his hypertension, and right kidney function deteriorated. An arteriogram showed two stenotic renal arteries supplying the right kidney. The smaller inferior artery supplied 35% of the kidney. Selective vein renin levels were greater than 15,000 ng/dL on the right side. Technical considerations in the repair of this lesion included midline transabdominal incision to expose the abdominal aorta and the inferior vena cava; dissection of inferior vena cava (IVC) with division of selected lumbar veins; full mobilization of right kidney and transsection of both renal arteries and the renal vein; perfusion of kidney via each renal artery with cold Sach's solution after resection of arterial stenoses; end-to-side microvascular anastomosis of the smaller (2 mm) renal artery to the main renal artery at the hilum with 10-0 nylon over in situ perfusion cannula; renal artery passed under the IVC to the aorta; and right kidney autotransplanted to a new site on the abdominal aorta with an end-to-side (5.0 mm) renal artery to the aorta and an end-to-side renal vein to IVC anastomosis. Following revascularization, perfusion was excellent and the blood pressure returned to normal. At 6 months follow-up, selective renal vein renins were normal and an arteriogram showed no stenosis. Meticulous dissection, cold perfusion, microvascular anastomosis, and autotransplantation salvaged this kidney and resolved the hypertension.