Renal autotransplantation in children: a successful treatment for renovascular hypertension

Renovascular hypertension in children is not a common disease. With improved surgical technique the incidence of nephrectomy has decreased and renovascular reconstruction is currently the preferred method to manage this entity. Between 1977 and 1988, 21 patients with renovascular hypertension were treated at our hospital: 7 patients 6 to 16 years old underwent renal autotransplantation. Of the children 4 had unilateral and 3 had bilateral disease requiring bilateral autotransplantation. Autotransplantation was performed by anastomosis of each renal artery end-to-side to the common iliac artery. The renal veins were anastomosed end-to-side to the common iliac veins. The ureters were left intact in all but 1 patient who required a bench operation. Of the 4 patients who had a unilateral procedure 3 are cured and 1 is improved with a normal blood pressure on a small dose of antihypertensive medication. The 3 patients with bilateral autotransplants are cured. These results, with normalization of the blood pressure in 86% of the patients and improvement in blood pressure in 14% with a patency rate of 87%, are similar to other reported reconstructive modalities in children.     

Follow‐up after unilateral nephrectomy in children: is an estimate of glomerular filtration rate necessary?

OBJECTIVE: To determine the need for an estimate of glomerular filtration rate (GFR) in the follow-up of children undergoing unilateral nephrectomy for benign renal disease. PATIENTS AND METHODS: Forty-four children (21 girls and 23 boys) undergoing unilateral nephrectomy for benign renal disease over a 3-year period were reviewed for the underlying diagnosis and indication for nephrectomy, imaging before and after surgery, postoperative GFR and final outcome. The follow-up included ultrasonography (US) of the contralateral kidney at 3 and 12 months and an estimate of GFR before discharge at > or = 1 year. All children were aged > 2 years when the GFR was measured. The criteria for discharge were normal imaging of the contralateral kidney before and after surgery and a normal GFR afterward. Spearman's correlation coefficient was used to determine the relationship between age, GFR and contralateral renal length after surgery. RESULTS: The median (range) age at surgery was 2.5 (0.67-16) years. The indications for nephrectomy included reflux nephropathy in 18, multicystic dysplastic kidney in 12, a congenital obstructive uropathy in eight, congenital renal dysplasia in four and miscellaneous in two. All patients had a normal contralateral kidney before surgery on US and functional imaging, and normal US at the follow-up, with evidence of compensatory hypertrophy in all. The median (range) corrected GFR for the 44 children was 109 (81-140) mL/min/1.73 m2, with no correlation between age and GFR, or between renal length and GFR. CONCLUSION: After unilateral nephrectomy for benign renal disease, provided there is a structurally and functionally normal contralateral kidney before surgery, with no abnormality on US, a routine estimate of GFR is unnecessary before discharge from follow-up. There was no correlation between GFR and age or renal length.     

Renovascular injury: an argument for renal preservation

BACKGROUND: Renovascular injury is uncommon among children. This study hypothesized that preservation of the severely injured kidney can be achieved safely without renal insufficiency, postinjury hypertension, or the need for hemodialysis. METHODS: Retrospective chart review of renal injuries seen between 1997 and 2001 at a level 1 pediatric trauma center was conducted. Severity of injury was graded by the American Association for the Surgery of Trauma Organ Injury Severity Scale. The outcome variables included the need for hemodialysis, impaired renal function (creatinine), and postinjury hypertension. RESULTS: In this study, 34 children presented with grade 1, 2, or 3 injury (74%), whereas 13 children presented with grade 4 or 5 renovascular injury (28%). The children with unilateral renovascular injury who underwent either nephrectomy or renal preservation had comparable outcomes with no hypertension, hemodialysis, or renal insufficiency in either group. CONCLUSIONS: The treatment outcomes were not different between the patients who underwent renal preservation and those who had immediate nephrectomy. The authors conclude that renal preservation should be attempted for all children with grade 4 or 5 renovascular injury.     

The role of partial nephrectomy in the treatment of pediatric renal hypertension

PURPOSE: From 5% to 25% of hypertension in children is renovascular compared with only 1% in adults. Although much attention is given to renovascular disease involving the main renal arteries, renin producing renal disease may also be intrarenal, involving abnormalities of the segmental vessels or renal parenchyma. We present our results of partial nephrectomy in this unique group of pediatric patients with hypertension in whom renin dependent hypertension involved only a segment of the kidney. MATERIALS AND METHODS: Six patients 10 months to 16 years old were referred for the evaluation of hypertension. Initial evaluations included computerized tomography, ultrasound, voiding cystourethrography and radionuclide renal scan. Renal arteriography with renal vein renin sampling was performed in 5 patients, of whom 4 underwent selective segmental renal vein sampling. Diagnoses included segmental hypoplasia (Ask-Upmark kidney), reflux associated scarring and renal arteriovenous malformation. RESULTS: In patients who underwent selective segmental renal vein sampling an increased renin level was present in the area of the renal lesion (mean 24.9 ng./ml. per hour, range 9.2 to 40.6) compared to the ipsilateral renal vein (15.6, 114 to 29.8). Three patients had evidence of contralateral suppression of renin secretion. All 6 patients underwent upper, lower or mid segment partial nephrectomy. All patients became immediately normotensive and remained so at a mean 10 years of followup. CONCLUSIONS: Partial nephrectomy provides an excellent nephron sparing cure for segmental renal hypertension. In the pediatric population selective segmental renal vein renin sampling is invaluable for locating the renin producing lesion. As in adults, contralateral renin suppression is predictive of surgical cure.     

Renal artery revascularisation can restore kidney function with absent radiotracer uptake

Background

Children with renovascular hypertension often present with severe hypertension. Some children have severe obstruction of their renal arteries resulting in <10% relative function on [^99mTc]dimercaptosuccinic acid (DMSA) scan. Conventional treatment of these children has been nephrectomy of the poorly functioning kidney to normalise their blood pressure (BP).

Case-Diagnosis/treatment

We describe three children aged 20 months to 9 years with severe renal artery stenosis and severe hypertension who had radionucleotide uptake of 0% in one kidney. In one case, no renal perfusion was demonstrated by duplex ultrasound scan. Significant recovery of relative renal function of 18 to 52% was achieved after revascularisation by percutaneous angioplasty or open surgery of the obstructed renal artery.

Conclusion

These cases illustrate that scintigraphy alone cannot be used to predict salvageable function in children with renovascular disease.     

Treatment of renovascular hypertension by unilateral nephrectomy. A follow-up study in patients above 60 years of age

The long term results of surgical intervention in 26 elderly patients with renovascular hypertension are presented. All patients were above 60 years of age at the day of operation. The majority of the patients had atherosclerotic renovascular disease with only one case of fibromuscular dysplasia. Several patients had severe extrarenal atherosclerotic disease. The diagnosis of renovascular hypertension was based upon the results of isotope renography, renal arteriography and renal vein catheterization. All patients underwent unilateral nephrectomy. Notably, no deaths or complications occurred in relation to surgery. At the follow-up study, blood pressure was lowered and the requirement for antihypertensive drugs reduced in 86% of the patients. We conclude that unilateral nephrectomy in elderly high risk patients with renovascular hypertension is a safe and efficient procedure.     

Renovascular hypertension in children. Report of seven cases treated surgically including two cases of renal autotransplantation

Seven children between the ages of three and seventeen years have been treated surgically for renovascular hypertension. Two additional cases treated elsewhere but studied subsequently are cited because of special features of interest. Two patients had primary nephrectomy because of irreparable vascular lesions and contralateral intact kidneys. One patient was treated with midsegmental partial nephrectomy for intimal and medial fibroplasia. Another patient with duplex renal arteries and stenosing lesions involving the upper main renal artery to the left kidney and lower segmental artery to the right kidney was treated by left nephrectomy and right lower pole resection. One patient with subadventitial fibroplasia was treated with a hypogastric artery autograft, and two patients were treated with autotransplantation, one having had simultaneous contralateral nephrectomy for a nonfunctioning kidney because of a previously unsuccessful splenorenal bypass.     

Effects of renal denervation of the contralateral kidney on blood pressure and sodium and eicosanoid excretion in the chronic phase of two-kidney, one-clip renovascular hypertension in rats

OBJECTIVE: To define the role of the renal nerves of the contralateral kidney in the maintenance of two-kidney, one-clip (2K-1C) renovascular hypertension in rats. MATERIAL AND METHODS: The contralateral kidney of 2K-1C rats was denervated 6 months after induction of hypertension and 4 weeks after nephrectomy of the clipped kidney. Blood pressure, sodium and potassium balance and eicosanoid excretion were measured. RESULTS: Denervation of the contralateral kidney induced normalization of blood pressure in post-Goldblatt hypertensive rats. This effect was not mediated by a negative sodium balance. Excretion of prostaglandin E2 and thromboxane B2 increased after denervation of the contralateral kidney in both post-Goldblatt hypertensive and post-Goldblatt normotensive rats, while urine extraction remained unaffected. CONCLUSION: Afferences from the contralateral kidney appear to participate in the maintenance of 2K-1C renovascular hypertension due to the activation of central mechanisms regulating blood pressure.     

Renal autotransplantation and extracorporeal reconstruction for complicated benign and malignant diseases of the urinary tract

Renal autotransplantation was performed in five patients and extracorporeal vascular reconstruction was required in two of these cases. One had a carcinoma of the mid-ureter with a solitary kidney. Two patients had ureteral injury. One was iatrogenic from a prior operation, and the other had intrinsic ureteral disease secondary to schistosomiasis. The fourth patient had renovascular hypertension with disease extension into the interlobar renal arteries and a single kidney. The final patient had a large, renal arteriovenous malformation and polycystic kidneys. All have functioning grafts at follow-up ranging from 10 to 36 months. There is no evidence of tumor recurrence after 30 months in the patient with ureteral malignancy. The patient with renovascular hypertension has adequate blood pressure control with medication 12 months after surgery. His creatinine which had risen in the post-operative period to 4.2 mg/dl, has returned to its pre-operative valve of 1.8 mg/dl. None of the other four patients had any post-operative decline in renal function. These cases illustrate that the technique of nephrectomy, extracorporeal surgery, and renal autotransplantation can be applied to a variety of benign and malignant diseases of the kidney and ureter not amenable to conventional in-situ correction, thus allowing maximal preservation of renal parenchyma. We also have demonstrated that the procedure can be successfully performed in the presence of significant infectious risk (Case 2: indwelling nephrostomy), and retroperitoneal infection (Case 3: schistosomiasis). We feel that this procedure is currently underutilized.(ABSTRACT TRUNCATED AT 250 WORDS)     

Autotransplantation for renovascular hypertension with complete renal artery occlusion.

We report a personal series of 13 autotransplantation procedures in 12 patients who suffered from severe renovascular hypertension. In all of these cases preoperative investigation demonstrated a viable kidney, despite complete occlusion of the affected renal artery. One-half the patients had stenosis of a milder degree affecting the contralateral kidney. In eight of these patients the operation was considered successful. One patient died due to postoperative superior mesenteric artery thrombosis and two had infarction of the transplanted kidney. A fourth patient lost the autotransplant because of postoperative haemorrhage. It is suggested that if medical treatment fails then autotransplantation should be considered in place of nephrectomy for cases of renovascular hypertension with complete occlusion of the renal artery.     

The surgical management of renovascular hypertension in children and young adults.

OBJECTIVES: To assess the outcome and durability of operative revascularisation in young patients with renovascular hypertension. DESIGN: Retrospective study. METHOD: The records of all young patients (under 25 years) operated on for renovascular hypertension at St Mary's Hospital 1988-1998 were reviewed. We assessed the aetiology of hypertension, operations performed, effect of treatment on blood pressure, renal function and requirement for antihypertensive medication during follow-up. RESULTS: Ten patients were identified who had been considered for surgery, of median age 16 years (22 months to 22 years). Fibromuscular dysplasia was present in five patients, mid-aortic syndrome (MAS) in four and neurofibromatosis in one. Operations performed were aortorenal bypass (three), aorto-aortic bypass+/-renal bypass (three), splenorenal bypass (one) and autotransplantation (one). Of the three patients treated by balloon angioplasty, only one had a successful result. One patient with MAS is currently awaiting surgery. Over a median follow-up of 24 months (8-144), seven patients are normotensive off all antihypertensive medication. Of two patients on reduced doses of medication, one (splenorenal bypass) required surgical repair of a late (9 years) coeliac stenosis. CONCLUSIONS: The surgical treatment of renovascular hypertension in carefully selected young patients gives durable results. Blood pressure is well controlled long-term, and the need for antihypertensive medication is removed altogether in the majority of patients.     

Partial nephrectomy for renal cell carcinoma: indications, results and implications

Of 52 patients who underwent partial nephrectomy for tumor 44 were found to have renal cell carcinoma. The indications for this parenchyma-sparing procedure were categorized according to the initial status of the contralateral kidney and included bilateral tumors or tumor in a solitary kidney in 16 patients (mandatory indications), unilateral carcinoma with compromise of the contralateral kidney by a benign disease process in 9 (relative indications) and small peripheral tumor with a normal contralateral kidney in 19 (elective indications). There were 4 recurrences that accounted for 3 deaths, all in patients with mandatory indications. All patients who underwent partial nephrectomy for relative or elective indications were without definite evidence of recurrent disease at last followup (over-all mean 36 months). Our results suggest that conservative surgery can often provide effective and advantageous therapy for renal cancer and we encourage further consideration of the role of partial nephrectomy as an alternative to radical nephrectomy in selected patients with small peripheral tumors and normal contralateral kidneys.     

Calcified renal artery aneurism and high blood pressure. A case report and review of the literature

Renal artery aneurysm is a rare disease in children and usually is due to fibromuscular dysplasia. Clinical symptoms are frequently high blood pressure, abdominal pain, and hematuria. Diagnosis is carried out by means of angiography. We report the case of a 13-year-old male patient who had renovascular hypertension due to calcification and aneurysm of fibromuscular dysplasia-associated renal artery. We carried out total nephrectomy to resolve high blood pressure. We suggested that presence of discreet calcification in region of renal artery in a boy with renovascular high blood pressure should guide us toward diagnosis of fibromuscular dysplasia-related renal artery aneurysm.     

Contralateral renal hyperplasia and increased renal function after relief of chronic unilateral ureteral obstruction

Following relief of 1, 2 or 3 weeks of unilateral ureteral obstruction, contralateral compensatory renal growth and increased renal function were measured 3 and 6 months later. Compensatory growth occurred predominantly by hyperplasia, demonstrated by a significant increase in DNA content and a decrease in the RNA:DNA ratio (p less than 0.04). This is in contrast to compensatory growth following nephrectomy or unrelieved unilateral ureteral obstruction, which occurred primarily by hypertrophy with no significant change in DNA content but a significant increase in RNA content and the RNA:DNA ratio (p less than 0.04). Contralateral renal function in animals with relieved unilateral ureteral obstruction was greater than in controls with 2 normal kidneys (p less than 0.05). The contralateral increase in renal function was greater than that in animals subjected to ipsilateral nephrectomy or unrelieved ureteral obstruction, but this did not reach statistical significance. Thus, when growth occurred by hyperplasia, there was a trend to greater increases in renal function than when growth occurred by hypertrophy. Contralateral compensatory renal hyperplasia and increased renal function occurred in conjunction with a decrease in renal mass and function of the ipsilateral post-obstructed kidney. These experiments suggest that the post-obstructed, poorly functioning kidney stimulates contralateral hyperplastic growth and increased renal function. This hyperplastic response is different from the hypertrophic response following nephrectomy or unrelieved unilateral ureteral obstruction, implicating the post-obstructed kidney as the stimulus of the hyperplastic response.     

Role of eicosanoids of the contralateral kidney in maintenance of two-kidney, one-clip renovascular hypertension in rats

OBJECTIVE: To elucidate the role of the eicosanoids prostaglandin E(2) (PGE(2)), 6-keto-prostaglandin F(1a) (PGF(1a)) and thromboxane B(2) (TXB(2)) in the maintenance of two-kidney, one-clip renovascular hypertension in rats. MATERIAL AND METHODS: The right renal artery was constricted by a silver clip in 63 male Sprague-Dawley rats to induce hypertension, while a sham operation was performed in 17 control rats. Six months after the induction of hypertension, nephrectomy of the clipped kidney was performed. Nephrectomy was followed by a period of high sodium intake. Blood pressure and eicosanoid excretion were measured before and after nephrectomy of the clipped kidney, as well as during high sodium intake. RESULTS: During the chronic phase of Goldblatt hypertension, the amount of vasoconstrictive TXB(2) excreted by the contralateral kidney increased compared to that in the controls, whereas PGE(2) excretion was unaffected. Eicosanoid excretion before and after removal of the clipped kidney did not differ between post-Goldblatt hypertensive and post-Goldblatt normotensive animals. During the period of high sodium intake, PGE(2) excretion increased only in control rats, being unaltered in Goldblatt hypertensive rats. CONCLUSIONS: In the chronic phase of two-kidney, one-clip renovascular hypertension, the contralateral kidney of post-Goldblatt hypertensive and post-Goldblatt normotensive rats excretes more vasoconstrictive thromboxane in comparison to controls, whereas excretion of vasodilatory prostaglandin is not elevated. However, increased TXB(2) excretion and the absence of an increase in PGE(2) excretion from the contralateral kidney do not appear to be important for the maintenance of high blood pressure in this model of renovascular hypertension.     

Late results after surgical treatment of renovascular hypertension. A follow-up study of 122 patients 2-18 years after surgery.

During the period 1963-1980, 122 patients were operated on for renovascular hypertension at surgical department D, vascular section, Rigshospitalet, Copenhagen. Seventeen patients, with a median age of 24 years, had fibromuscular hyperplasia and 95 patients, with a median age of 48 years, had atherosclerosis. Twenty-four of the latter had bilateral renal artery lesions and 71 had unilateral disease. Ten patients had various other causes of renovascular hypertension. Operative mortality was 4.9%, decreasing to two per cent in the last 8 years. At discharge, 71% of the patients were normotensive without medication, 18% were improved, and 11% were unimproved. At follow-up in 1982, the actuarial 10-year survival rates for patients with unilateral and bilateral atherosclerotic disease were 65% and 48%, respectively. There was no difference between survival rates for patients with fibromuscular hyperplasia and an age- and sex-matched, population. Sixty-nine patients were reexamined with a median follow-up of 9 years. Of the survivors with atherosclerosis, 87% benefitted from the operation: 50% were normotensive without medication and 37% were improved. Of patients with fibromuscular hyperplasia, 93% benefitted from operation: 79% were normotensive and 14% were improved. The results support the value of surgery in patients with renal fibromuscular hyperplasia and to the long-term benefits of surgical treatment of patients with atherosclerotic renovascular disease.     

Renovascular hypertension in children: current concepts in evaluation and treatment

Since 1981, we have evaluated and treated 22 children with renovascular hypertension (RVH). Seventeen patients had stenosis of their native renal arteries, and five had stenosis of the artery in a transplanted kidney. RVH was caused by fibromuscular dysplasia in 13 patients, by trauma in 2 patients, and by arteritis in 2 patients. Among the patients who had transplanted kidneys, three had technical causes for stenosis and two had stenosis due to rejection. The disease was unilateral in 10 patients, bilateral in 5, and present in a solitary kidney in 7, including the five renal transplants. Diagnostic studies that strongly suggested the presence of renovascular disease were an initial diastolic blood pressure greater than 100 mm Hg, an elevated peripheral vein renin activity level, and an abnormal renal scan if the patient's hypertension was being controlled with an angiotensin-converting enzyme inhibitor (ACEI). Only the renal arteriogram was 100% accurate in confirming the presence of RVH. Percutaneous angiographic correction was attempted in 13 patients and resulted in lasting improvement of the hypertension in five (38%). Surgical revascularization was attempted in 17 children, including the 8 with failed angioplasty, with improvement or cure of the hypertension in 15 patients (88%). Combining percutaneous transluminal angioplasty (PTA) and surgical results gave 20 of 22 patients (91%) with cure or improvement of their hypertension. Four of 27 affected kidneys (15%) could not be revascularized and were removed. We conclude from this series of patients that despite improvements in noninvasive studies, renal arteriogram remains the only study that is 100% accurate in evaluating children for RVH.(ABSTRACT TRUNCATED AT 250 WORDS)     

Unilateral multicystic dysplastic kidney: experience in children

OBJECTIVES: To report a retrospective study of unilateral multicystic dysplastic kidneys (MCDK) in children, assessing the contralateral kidneys and urinary tract, the functional consequences, and the urological and nephrological management and outcome, as unilateral MCDK is the most common cause of renal cystic disease in children, and malformations of the contralateral urinary tract and kidney (pelvi-ureteric obstruction, megaureter, reflux, renal dysplasia) have been reported. PATIENTS AND METHODS: The study included 97 patients (60 boys, 37 girls) with MCDK seen between 1985 and 1998; 82 were diagnosed in utero by ultrasonography (US). After birth, the diagnosis was verified by US, renal scanning (in 93) or intravenous urography (in four), and 89 (92%) had voiding cysto-urethrography (VCUG). Of the 97 children, 87 (90% had a mean (range) follow-up of 44.3 (15-115) months. RESULTS: The MCDK was removed in 17 children; the follow-up of 75 children (five lost to follow-up) showed total involution of the MCDK in 25%, shrinkage in 60% and a stable size in 15%. None had any sign of malignancy. The contralateral kidney showed anomalies in 19 of 97 children (20%); 12 had a dilated renal pelvis (two with megaureter), six had a high echogenicity of the contralateral kidney (one had reflux, and two also pelvic dilatation). In only four of the 89 children was reflux found by VCUG; 16 of the 19 anomalies were detected by US. Five children needed surgery on the contralateral urinary tract (three a pyeloplasty, and one each a pyeloplasty plus ureteroneocystostomy, and an antireflux procedure). Of the contralateral kidneys 43% showed compensatory hypertrophy. There was mild renal insufficiency in three children; renal function seemed to be slightly impaired in many. Five infants had hypertension (four with spontaneous resolution) caused by renal scarring after pyelonephritis or inborn dysplasia of the contralateral kidney. There were symptomatic urinary tract infections in seven children. CONCLUSION: US can be used safely to diagnose unilateral MCDKs and malformations of the contralateral urinary tract and kidney. In cases where US of the dysplastic kidney remains uncertain renal scintigraphy is necessary to detect the lack of renal function. The low rate of reflux makes routine VCUG unnecessary if the contralateral upper urinary tract and kidney appear to be normal on US. Nephrectomy of the dysplastic kidney in typical cases is also unnecessary. A long-term nephro-urological follow-up of children with MCDK is recommended.     

MRI detection of atrophic kidney in a hypertensive child with a single kidney

The role of magnetic resonance imaging (MRI) in the work-up of secondary causes of pediatric hypertension is typically restricted to that of renovascular causes where main renal artery stenosis is suspected. We report a case of a 10-year-old female child with hypertension, who was thought to have unilateral renal agenesis, because only a solitary left kidney could be visualized on both ultrasound and renal scintigraphy. Our patient underwent magnetic resonance imaging because of suspected renal artery stenosis in her solitary left kidney. At MRI she was found to have a normal left kidney. However, a very tiny, atrophic right kidney was also visualized. A laparoscopic right nephrectomy was performed, which resulted in complete resolution of her hypertension. This case illustrates a possible additional role for MRI in a very small subset of pediatric hypertensive patients: those with a single kidney on ultrasound.     

Live donor renal transplants using kidneys with arteriographic evidence of mild renovascular disease

The objective of the study was to determine whether using a living donor kidney with arteriographic evidence of renovascular disease affects the outcome of the recipient's transplanted graft. Twenty-eight patients who had unilateral renovascular abnormalities on conventional angiography underwent donor nephrectomy of the ipsilateral kidney. Results in the recipients who received these kidneys were reviewed. Comparison was made to a control group of living donor renal transplant recipients who were matched for donor, recipient age. Graft survival, patient survival, serum creatinine for all 28 recipients were evaluated. All 28 donors underwent a successful donor nephrectomy. Recipient graft survival was 96% at 1 yr, 92% at 3 yr, 71% at 5 yr, 62% at 10 yr. Mean serum creatinine values at 1 month, 1 yr, 3 yr were 1.5, 1.5, 1.6, respectively. Similar results were observed in the control group. We conclude that renal transplantation utilizing kidneys with arteriographic evidence of renovascular disease results in excellent short, long-term renal allograft survival.