Clin. Radiol. (1977) 28, 339-344 C R O S S E D R E N A L E C T O P I A : C L I N I C A L A N D R A D I O L O G I C A L F I N D I N G S I N 22 C A S E S M. HERTZ, Z. J. RUBINSTEIN, N. SHAHIN and M. MELZER*
The Department of Radiology and *Urology, The Chaim Sheba Medical Center and Tel-Aviv University Medical School, Israel The clinical and radiological features of 22 patients with crossed ectopic kidneys are reported, including a case with unusual mobility of an unfused ectopic kidney. In some cases the anomaly was an incidental finding. However, complications were frequent and included seven hydronephrotic and three non-functioning kidneys, t w o o f the latter were found to be obstructed by a calculus. Vesico-ureteral reflux was demonstrated in three of the five children in whom the examination was performed. Anomalous blood supply was present in all patients who underwent renal arteriography or surgery. Skeletal anomalies were present in 11 patients, one of whom had in addition coarctation of the aorta, and another atrial septal defect and anal atresia. Crossed renal ectopia is an uncommon anomaly in which both kidneys lie on the same side. Only a few reports of this interesting condition could be found in the English radiological literature and it was therefore considered worthwhile to report the 22 patients with crossed renal ectopia diagnosed at our hospital. As the diagnosis is essentially a radiological one, the emphasis is on the relevant radiological findings. MATERIAL AND FINDINGS The clinical and main radiological findings of 22 patients with crossed renal ectopia, diagnosed at the Chaim Sheba Medical Center, are presented in Table 1. All the cases except for three were seen in the last 10 years (1965-75). This represents our experience in a 1200-bed general teaching hospital, which, because of its size, location and facilities, also serves as a referral centre for smaller hospitals and clinics. Approximately 3000 excretory urograms are performed annually. The oldest patient in the series was 66 years of age, the youngest 5 days old. The sex ratio was 14 males to 8 females. Symptoms were sometimes referable to the urinary tract, but renal ectopia was often an incidental discovery in patients being investigated for non-specific abdominal pain. In seven of our patients pain on the side of the displaced kidney was the presenting s y m p t o m Additional congenital anomalies were found in the skeletal, cardiovascular and gastrointestinal systems in 11 patients (Table 1). Excretory urography was performed in all 22 patients and was diagnostic of crossed ectopic kidney Address for reprints: Marjorie Hertz, M.D., Department of Radiology, The Chaim Sheba Medical Center, Tel-Hashomer, Israel_ 19
in 19 of them. In the remaining three patients the crossed ectopic kidney did not function. In two of these, the pelvis of the ectopic kidney was obstructed by a stone which was demonstrated by retrograde pyelogram in one of them. In the other case the diagnosis of crossed ectopic kidney with stone obstruction was made at appendectomy. Surgical exploration of the abdominal mass in the third patient, a 5-day-old infant, revealed the existence of a non-functioning dysplastic crossed" ectopic kidney, which was removed. In nine patients both kidneys were on the left, one with unfused kidneys and in 12 both were on the right side (Table 2); in three of the latter the kidneys were not fused. In the remaining case a single, crossed ectopic kidney was situated in the bony pelvis. Of the 17 patients with fused kidneys end-to-end fusion (Fig. 7) with both pelves facing the same way, or with the upper pelvis medially and the lower pelvis laterally, was present in 14 cases. In three patients an L-shaped right angle fusion was seen with the ectopic kidney lying transversely (Fig. 2). In all patients both the normal and the ectopic kidneys were malrotated, with the latter being situated inferiorly except for one case (No. 17). In the absence of calculi, abnormal pelvis dilatation in a normally situated or an ectopic kidney, was found to be due to idiopathic uretero-pelvic junction narrowing. Cysto-urethrography was performed in six patients and marked vesico-ureteral reflux was present in three of them (Fig. 3), all of whom were children. These proved to have urinary tract infection as well. In one child, an antireflux operation was performed with good results and in another child the reflux disappeared 1 year after conservative treatment with antibiotics.
340
CLINICAL RADIOLOGY
Table 1 - Clinical and radiological findings in 22 patients with crossed renal ectopia No.
Sex
Age
Indications for excretory urography
Main radiotogical findings
1
F
7 yr
Abdominal pain, mass in left abdomen
2
M
30 yr
Absence of ejaculation
3
M
45 yr
Fever,mass in abdomen
4 5
M F
19 yr 4 yr
Trauma to back, haematuria Urinary tract infection
6
M
7 8 9 10
M M M M
53 yr 17 yr 26 yr 26 yr
Dysuria following mumps Hypertension Hypertension Right flank pain, liaematuria
Two kidneys left fused, ectopic kidney hydroephrotic Sacral midline kidney, trabeculated bladder wall, narrow bladder neck Two kidneys right fused, right kidney hydronephrotic, ectopie kidney obstructed by stone Two kidneys left fused Two kidneys left fused, bilateral vesico-ureteral reflux Two kidneys left fused, left kidney hydronephrotic, bilateral vesieoureteral reflux Two kidneys left fused Two kidneys left fused Two kidneys left fused Two kidneys right fused
11 12 13 14 15 16
F F M F M M
3 yr 22 yr 18 yr 51 yr 24 yr 2 yr
Urinary tract infection Abdominal pain Right flank pain, haematuria Abdominal pain, mass in abdomen Hypertension Urinary tract infection
17
F
2% yr Urinary tract infection
18
M
5 day Mass in abdomen
19
F
52 yr
Abdominal pain
20
M
66 yr
Abdominal pain
21
F
1 yr
22
M
5 ruth Congenital anomaly of aorta
Other congenital anomalies
12 day Other congenital anomalies
Two kidneys right fused Two kidneys right unfused Two kidneys right fused Two kidneys right unfused Two kidneys right fused Two kidneys right fused, bilateral vesico-ureteral reflux Two kidneys right fused, ectopic superior, both kidneys hydronephrotic One kidney right hydronephrotic, 1 non-functioning (crossed ectopic) Two kidneys right fused, ectopic not excreting, obstructed by stone Two kidneys left unfused, eetopic hydronephrotic Two kidneys right fused Two kidneys left fused
Arteriography was performed in five patients and demonstrated an abnormal renal blood supply in each instance (Fig. 4). The case of single crossed renal ectopia had a single renal artery arising from the common iliac artery. In the remaining four patients, a total of eight kidneys were supplied by 10 renal arteries. The sites of origin were from the common iliac artery (two renal arteries), distal aorta at the L 3 - 4 level (four renal arteries), and the aorta at the D12 level (three renal arteries). Only one renal artery
Additional anomalies
Absence of second kidney, osteopoikilosis Anomaly of sacrum
Coarctation of aorta clinodactyly
Spina bifida $1 Spina bifida S1 Six lumbar vertebrae, spina bifida SI Anomaly of sacrum Spina bifida $1
Absence of sacrum, lumbar hemivertebrae club feet, bilateral congenital dislocation of hip joints
Atrial septal defect atresia ani, asymmetry of face, vertebral anomalies Low set ears, maldeveloped left thumb
arose from the expected level of L1, and then from its anterior rather than the lateral surface. In one patient (Case 14) the crossed ectopic kidney was extremely mobile. On excretory urography and after applying pressure to the abdomen by means o f a rubber balloon, the left kidney could be seen on the right side o f the abdomen, somewhat inferiorly to the right kidney (Fig. 5a). An erect view then showed the ectopic left kidney to have descended low in the pelvis, slightly to the right of
CROSSED RENAL ECfOPIA Table 2 - Location and state o f fusion in 22 patients with crossed renal eetopia
Side Right Left Midline Fused Unfused 12
9 8
9
3 1
1" * Single midline kidney with left ureter, and blood supply from the right iliac artery.
341
Fig. 1 - Case 8. Crossed ectopic kidney with end-to-end fusion, Note the insertion o f the right ureter into its normal place in the bladder. There is an associated sacral anomaly. Fig. 2 - Case 10. Crossed ectopic kidney with L-shaped fusion. The ectopic kidney is lying horizontally over the spine. Six lumbar vertebrae and sacral spina bifida are also demonstrated. Fig. 3 - Case 5. Crossed ectopic kidney, fused, with bilateral vesicoureteral reflux on cystogram. Fig. 4 - Case 4. Crossed ectopic kidney, fused. Arteriogram. (a) Arterial phase showing multiple renal arteries. Right inferior adrenal artery (arrow) comes off right renal artery before the latter crosses the midline. (b) Nephrogram. Fused, left-sided kidneys. Note the right adrenal gland in its normal position (arrows).
342
CLINICAL RADIOLOGY
the midline (Fig. 5b). Diagnosis of unfused crossed ectopic kidney with abnormal mobility was made. Eleven of our patients had anomalies in other organs. All of them showed some form of skeletal abnormality, eight of them in the lumbar spine and one with an absent sacrum. One of these (Case 6) had in addition coarctation of the aorta and another (Case 2) had anal atresia, atrial septal defect and facial asymmetry. The patient with the solitary crossed ectopic kidney had osteopoikilosis. DISCUSSION Crossed renal ectopia is an uncommon condition in which one kidney crosses the midline to the opposite side of the spine (Emmett, 1963). The ectopic kidney is most often malrotated, and situated below the normal kidney. Both kidneys are usually fused together, in such a way that the upper pole of
Fig. 5 - Case 14. Crossed ectopic kidney, unfused, mobile, (a) After applying a pressure balloon, the ectopic kidney (arrow) is situated immediately caudal to the right kidney. (b) Erect position. The ectopie kidney has now descended into the bony pelvis (arrow).
the lower kidney is fused with the lower pole of the upper one. In some cases the pelvis of the normal kidney is projected anteromedially and of the lower kidney anterolaterally. This is called a sigmoid kidney (Campbell, 1954). It may be considered a transition form of horseshoe kidney, but in crossed ectopy both kidneys lie for their greater part on one side of the spine, while the ureter of the crossed kidney recrosses the midllne and enters the bladder in its normal side. The incidence of crossed renal ectopia at autopsy ranges from 1:7600 (Wilmer, 1938) to 1:1300 (Campbell, 1963). Crossed ectopia without fusion is much rarer and occurs in 10-15% of all crossed ectopic kidneys (Lee, 1949; Gray and Skandalakis, 1972), with only about 60 cases having been reported (Caine, 1956; Moshkowitz and Abrahamov, 1969). Very few cases of solitary crossed renal ectopy have been reported. Purpon (1963) reviewing the literature found eight cases, including his own. Since then at least two more cases have been reported (Tabriski and Bhisitkul, 1965; Weiss, et al., 1965). There seems to be a slight preponderance of this anomaly in males and the two kidneys are more often found on the right side (McDonald and McClellan, 1957). This was also found in our series. Crossed ectoNc kidney may
CROSSED RENAL ECTOPIA be discovered at any age, but is most frequently found in the third decade of life. We found no predilection of age period at the time of diagnosis in our patients. The embryological development of crossed renal ectopia is not clear, and several hypotheses have been put forward such as faulty development of the ureteric buds or vascular obstruction to the ascent of the permanent kidney (Abeshouse, 1947; Malek and Utz, 1970). However, factors other than mechanical ones may be involved as the renal anomaly is seen to be associated with congenital abnormalities in other organs. Neidhardt et al. (1967) mention a possible teratogenic factor acting at the mesoblastic stage in the early embryo, thus explaining anomalies in other mesoblastic formations such as the skeleton. The anomaly may be an incidental discovery. In symptomatic patients pain is the most frequent complaint, occurring on the side of the displaced kidney, and was noted to be present in seven of our cases. Dysuria and frequency of micturition are also mentioned as presenting symptoms, as are haematuria, pyuria and a palpable mass in the abdomen. In four of our patients, an abdominal mass was palpated. In the others, excretory urography was performed for a wide variety of symptoms and signs, such as hypertension (three cases), absence of ejaculation, haematuria following a road accident with trauma to the back, congenital anomalies in other organ systems, and urinary tract infection in children (see Table 1). A plain film of the abdomen may demonstrate an abdominal mass caudal to the kidney region and absence of a normal kidney shadow contralaterally. The diagnosis is usually established by excretion urography. With normal-functioning kidneys the excretory urogram will show both the collecting systems to be on one side. The crossed ectopic kidney is almost always the inferior one, and only in one of our cases was it the superior one (Case 17). The upper pole of the lower kidney is usually fused with the lower pole of the upper one. It is important to demonstrate either by excretory urography or by retrograde pyelography the ureter of the crossed ectopic kidney and to show that its insertion into the bladder is in its normal place. This helps the differentiation from duplex kidney with a contralateral non-functioning kidney. With non-fusion of the kidneys the ectopic kidney may be low in the pelvis and projected over the sacrum. Symptoms of abdominal pain in these patients may be due to excessive mobility of the ectopic kidney (Amesur, 1963) and a film in the upright position may help to demonstrate this mobility (patient no. 14; Fig. 5).
343
Cysto-urethrography should be performed as well, especially in children. Kelalis et al. (1973) found vesico-ureteral reflux in 14 out of 16 children with horseshoe or ectopic kidneys. These authors concluded that there is an abnormality at the ureterovesical junction which is responsible for the reflux. Of the five children in whom cysto-urethrography was performed in our series, bilateral reflux was demonstrated in three. In one of them the reflux disappeared after conservative treatment. It may be suggested that the reflux had been caused by infection of the bladder and subsided after the infection had cleared. One cannot exclude, however, the possibility of a congenitally incompetent valve mechanism at the uretero-vesical junction, perhaps due to a short intramural segment. With growth of the child this segment lengths and thus the ureterovesical junction becomes competent (Tanagho and Hutch, 1965). In one of the two children without reflux the ectopic kidney was dysplastic and not functioning. The blood supply to the kidneys was abnormal in all the patients, who underwent renal arteriography. No constant arterial pattern could be discerned, renal arteries taking off from the aorta as high as the D12 level and as low as the L 3 - 4 level as well as from the iliac arteries. It was of interest to note that even the arteries supplying the non-ectopic kidney arose from abnormal sites (Rubinstein et al., submitted for publication). It is not well known that patients with crossed renal ectopia may have anomalies in other organs. Malek et al. (1971) in a survey of 21 children with ectopic kidney, seven of which were crossed ectopic kidneys, found in 18 of them anomalies involving organ systems outside the genitourinary tract; 10 had skeletal anomalies, nine cardiovascular and seven gastrointestinal malformations. Kelalis et al. (1973) found such anomalies in 47 of 60 children who had renal ectopia and fusion, half of them involving the skeletal system. We found malformations in other organ systems in 11 of our patients. Two of them showed cardiovascular anomalies (Case 6 and Case 21), one had atresia of the anus and the others showed a variety of skeletal anomalies, most of them in the lumbar spine. The patient with single crossed ectopic kidney had osteopoikilosis. This finding is probably a coincidence as we have not found any reported cases of osteopoikilosis with renal anomalies nor any mention of this comparatively rare bone disorder in patients with crossed renal ectopia. Treatment in symptomatic cases of unfused crossed renal ectopia may be directed to nephropexy of the ectopic kidney and Diaz (1953) described such
344
CLINICAL RADIOLOGY
a successful procedure. In our patient with the mobile unfused crossed ectopic kidney, the pain was not severe enough to warrant surgery and this kidney functioned normally on the excretory urogram. Also, repair is often impossible in these cases because of the anomalous vascularisation. Two o f our patients have undergone nephrolithotomy. One child underwent bilateral uretero-vesical reimplantation and another one cystostomy with drainage. In three patients nephrectomy o f the diseased crossed ectopic kidney was performed. It is most important, o f course, to demonstrate a normally functioning kidney if treatment is planned for a diseased crossed ectopic kidney. Abeshouse (1947) quotes five cases o f operative death due to inadvertent total nephrectomy performed in patients in w h o m the true nature o f the anomaly was not recognised prior to surgery.
REFERENCES Abeshouse, B. S. (1947). Crossed ectopia with fusion. American Journal o f Surgery, 73, 658-682. Amesur, N. R. (1963). Crossed renal ectopia. British Journal o f Urology, 35, 11-16. Boatman, D. L., Culp, D. A., Jr, Culp, D. A. & Flocks, R. H. (1972). Crossed renal ectopia. Journal o f Orology, 108, 30-31. Caine, M. (1956). Crossed renal ectopia without fusion. British Journal o f Urology, 28, 257-258. Campbell, M. (1951). Clinical Pediatric Urology, pp. 159, 353. W. B. Saunders Co., Philadelphia. Campbell, M. (1954). Urology, VoL 1, pp. 279-280. W. B. Saunders Co., Philadelphia and London. Diaz, G. (1953). Renal ectopy: report of a case of crossed ectopy without fusion, with fixation of kidney in normal
position by the extraperitoneal route. Journal of the International College o f Surgeons, 19, 158-169. Gray, S. W. & Skandalakis, J. E. (1972). Embryology for Surgeons, pp. 475-478. W. B. Saunders Co., Philadelphia. Kelalis, P. P., Malek, R. S. & Sagura, J. W. (1973). Observations on renal ectopia and fusion in children. Journal o f Urology, 110, 588 592. Lee, H. P. (1948). Crossed unfused renal ectopia with tumor. Journal o f Urology, 61, 333-339. Malek, 1L S. & Utz, D. C. (1970). Crossed, fused, renal ectopia with an ectopic ureterocele. Journal o f Urology, 104, 665-667. Malek, R. S., Kelalis, P. P. & Burke, E. C. (1971). Ectopic kidney in children and frequency of association with other malformations. Proceedings of the Mayo Clinic, 46, 461-467. McDonald, J. H. & McClellan, D. S. (1957). Crossed renal ectopia. American Journal o f Surgery, 83, 995-1002. Moshkowitz, A. & Abrahamow, A. (1969). Crossed renal ectopia without fusion. Harefuah, 77, 343-344 (Hebrew). Neidhardt, J. H., Bouchet, A., Morin, A., Theoleyre, J. & Feldman, D. (1967). Apropos des malformations associ6es ~t certaines anomalies et ag6nesies r6nales. Lyon Medical, 217, 1582-1590. Purpon, I. (1963). Crossed renal ectopia with solitary kidney: a review of the literature. Journal of Urology, 90, 13-15. Rubinstein, Z. J., Hertz, M., Shahin, N. & Deutsch, V. Crossed renal ectopia: angiographic findings in 6 cases (submitted for publication). Tabriski, J. & Bhisitkul, I. (1965). Solitary crossed ectopic kidney with vaginal aplasia: a case report. Journal of Urology, 95, 33-35. Tanagho, E. A. & Hutch, J. A. (1965). Primary reflux. Journal o f Urology, 93, 158-164. Weiss, R. M., Maloney, P. K. & Boland, G. A. (1965). Crossed ectopia of a solitary kidney. Journal o f Urology, 94, 320-322. Wilmer, H. A. (1938). Unilateral fused kidney: a report of five cases and a review of the literature. Journal o f Urology, 40, 551-571.
The Department of Radiology and *Urology, The Chaim Sheba Medical Center and Tel-Aviv University Medical School, Israel The clinical and radiological features of 22 patients with crossed ectopic kidneys are reported, including a case with unusual mobility of an unfused ectopic kidney. In some cases the anomaly was an incidental finding. However, complications were frequent and included seven hydronephrotic and three non-functioning kidneys, t w o o f the latter were found to be obstructed by a calculus. Vesico-ureteral reflux was demonstrated in three of the five children in whom the examination was performed. Anomalous blood supply was present in all patients who underwent renal arteriography or surgery. Skeletal anomalies were present in 11 patients, one of whom had in addition coarctation of the aorta, and another atrial septal defect and anal atresia. Crossed renal ectopia is an uncommon anomaly in which both kidneys lie on the same side. Only a few reports of this interesting condition could be found in the English radiological literature and it was therefore considered worthwhile to report the 22 patients with crossed renal ectopia diagnosed at our hospital. As the diagnosis is essentially a radiological one, the emphasis is on the relevant radiological findings. MATERIAL AND FINDINGS The clinical and main radiological findings of 22 patients with crossed renal ectopia, diagnosed at the Chaim Sheba Medical Center, are presented in Table 1. All the cases except for three were seen in the last 10 years (1965-75). This represents our experience in a 1200-bed general teaching hospital, which, because of its size, location and facilities, also serves as a referral centre for smaller hospitals and clinics. Approximately 3000 excretory urograms are performed annually. The oldest patient in the series was 66 years of age, the youngest 5 days old. The sex ratio was 14 males to 8 females. Symptoms were sometimes referable to the urinary tract, but renal ectopia was often an incidental discovery in patients being investigated for non-specific abdominal pain. In seven of our patients pain on the side of the displaced kidney was the presenting s y m p t o m Additional congenital anomalies were found in the skeletal, cardiovascular and gastrointestinal systems in 11 patients (Table 1). Excretory urography was performed in all 22 patients and was diagnostic of crossed ectopic kidney Address for reprints: Marjorie Hertz, M.D., Department of Radiology, The Chaim Sheba Medical Center, Tel-Hashomer, Israel_ 19
in 19 of them. In the remaining three patients the crossed ectopic kidney did not function. In two of these, the pelvis of the ectopic kidney was obstructed by a stone which was demonstrated by retrograde pyelogram in one of them. In the other case the diagnosis of crossed ectopic kidney with stone obstruction was made at appendectomy. Surgical exploration of the abdominal mass in the third patient, a 5-day-old infant, revealed the existence of a non-functioning dysplastic crossed" ectopic kidney, which was removed. In nine patients both kidneys were on the left, one with unfused kidneys and in 12 both were on the right side (Table 2); in three of the latter the kidneys were not fused. In the remaining case a single, crossed ectopic kidney was situated in the bony pelvis. Of the 17 patients with fused kidneys end-to-end fusion (Fig. 7) with both pelves facing the same way, or with the upper pelvis medially and the lower pelvis laterally, was present in 14 cases. In three patients an L-shaped right angle fusion was seen with the ectopic kidney lying transversely (Fig. 2). In all patients both the normal and the ectopic kidneys were malrotated, with the latter being situated inferiorly except for one case (No. 17). In the absence of calculi, abnormal pelvis dilatation in a normally situated or an ectopic kidney, was found to be due to idiopathic uretero-pelvic junction narrowing. Cysto-urethrography was performed in six patients and marked vesico-ureteral reflux was present in three of them (Fig. 3), all of whom were children. These proved to have urinary tract infection as well. In one child, an antireflux operation was performed with good results and in another child the reflux disappeared 1 year after conservative treatment with antibiotics.
340
CLINICAL RADIOLOGY
Table 1 - Clinical and radiological findings in 22 patients with crossed renal ectopia No.
Sex
Age
Indications for excretory urography
Main radiotogical findings
1
F
7 yr
Abdominal pain, mass in left abdomen
2
M
30 yr
Absence of ejaculation
3
M
45 yr
Fever,mass in abdomen
4 5
M F
19 yr 4 yr
Trauma to back, haematuria Urinary tract infection
6
M
7 8 9 10
M M M M
53 yr 17 yr 26 yr 26 yr
Dysuria following mumps Hypertension Hypertension Right flank pain, liaematuria
Two kidneys left fused, ectopic kidney hydroephrotic Sacral midline kidney, trabeculated bladder wall, narrow bladder neck Two kidneys right fused, right kidney hydronephrotic, ectopie kidney obstructed by stone Two kidneys left fused Two kidneys left fused, bilateral vesico-ureteral reflux Two kidneys left fused, left kidney hydronephrotic, bilateral vesieoureteral reflux Two kidneys left fused Two kidneys left fused Two kidneys left fused Two kidneys right fused
11 12 13 14 15 16
F F M F M M
3 yr 22 yr 18 yr 51 yr 24 yr 2 yr
Urinary tract infection Abdominal pain Right flank pain, haematuria Abdominal pain, mass in abdomen Hypertension Urinary tract infection
17
F
2% yr Urinary tract infection
18
M
5 day Mass in abdomen
19
F
52 yr
Abdominal pain
20
M
66 yr
Abdominal pain
21
F
1 yr
22
M
5 ruth Congenital anomaly of aorta
Other congenital anomalies
12 day Other congenital anomalies
Two kidneys right fused Two kidneys right unfused Two kidneys right fused Two kidneys right unfused Two kidneys right fused Two kidneys right fused, bilateral vesico-ureteral reflux Two kidneys right fused, ectopic superior, both kidneys hydronephrotic One kidney right hydronephrotic, 1 non-functioning (crossed ectopic) Two kidneys right fused, ectopic not excreting, obstructed by stone Two kidneys left unfused, eetopic hydronephrotic Two kidneys right fused Two kidneys left fused
Arteriography was performed in five patients and demonstrated an abnormal renal blood supply in each instance (Fig. 4). The case of single crossed renal ectopia had a single renal artery arising from the common iliac artery. In the remaining four patients, a total of eight kidneys were supplied by 10 renal arteries. The sites of origin were from the common iliac artery (two renal arteries), distal aorta at the L 3 - 4 level (four renal arteries), and the aorta at the D12 level (three renal arteries). Only one renal artery
Additional anomalies
Absence of second kidney, osteopoikilosis Anomaly of sacrum
Coarctation of aorta clinodactyly
Spina bifida $1 Spina bifida S1 Six lumbar vertebrae, spina bifida SI Anomaly of sacrum Spina bifida $1
Absence of sacrum, lumbar hemivertebrae club feet, bilateral congenital dislocation of hip joints
Atrial septal defect atresia ani, asymmetry of face, vertebral anomalies Low set ears, maldeveloped left thumb
arose from the expected level of L1, and then from its anterior rather than the lateral surface. In one patient (Case 14) the crossed ectopic kidney was extremely mobile. On excretory urography and after applying pressure to the abdomen by means o f a rubber balloon, the left kidney could be seen on the right side o f the abdomen, somewhat inferiorly to the right kidney (Fig. 5a). An erect view then showed the ectopic left kidney to have descended low in the pelvis, slightly to the right of
CROSSED RENAL ECfOPIA Table 2 - Location and state o f fusion in 22 patients with crossed renal eetopia
Side Right Left Midline Fused Unfused 12
9 8
9
3 1
1" * Single midline kidney with left ureter, and blood supply from the right iliac artery.
341
Fig. 1 - Case 8. Crossed ectopic kidney with end-to-end fusion, Note the insertion o f the right ureter into its normal place in the bladder. There is an associated sacral anomaly. Fig. 2 - Case 10. Crossed ectopic kidney with L-shaped fusion. The ectopic kidney is lying horizontally over the spine. Six lumbar vertebrae and sacral spina bifida are also demonstrated. Fig. 3 - Case 5. Crossed ectopic kidney, fused, with bilateral vesicoureteral reflux on cystogram. Fig. 4 - Case 4. Crossed ectopic kidney, fused. Arteriogram. (a) Arterial phase showing multiple renal arteries. Right inferior adrenal artery (arrow) comes off right renal artery before the latter crosses the midline. (b) Nephrogram. Fused, left-sided kidneys. Note the right adrenal gland in its normal position (arrows).
342
CLINICAL RADIOLOGY
the midline (Fig. 5b). Diagnosis of unfused crossed ectopic kidney with abnormal mobility was made. Eleven of our patients had anomalies in other organs. All of them showed some form of skeletal abnormality, eight of them in the lumbar spine and one with an absent sacrum. One of these (Case 6) had in addition coarctation of the aorta and another (Case 2) had anal atresia, atrial septal defect and facial asymmetry. The patient with the solitary crossed ectopic kidney had osteopoikilosis. DISCUSSION Crossed renal ectopia is an uncommon condition in which one kidney crosses the midline to the opposite side of the spine (Emmett, 1963). The ectopic kidney is most often malrotated, and situated below the normal kidney. Both kidneys are usually fused together, in such a way that the upper pole of
Fig. 5 - Case 14. Crossed ectopic kidney, unfused, mobile, (a) After applying a pressure balloon, the ectopic kidney (arrow) is situated immediately caudal to the right kidney. (b) Erect position. The ectopie kidney has now descended into the bony pelvis (arrow).
the lower kidney is fused with the lower pole of the upper one. In some cases the pelvis of the normal kidney is projected anteromedially and of the lower kidney anterolaterally. This is called a sigmoid kidney (Campbell, 1954). It may be considered a transition form of horseshoe kidney, but in crossed ectopy both kidneys lie for their greater part on one side of the spine, while the ureter of the crossed kidney recrosses the midllne and enters the bladder in its normal side. The incidence of crossed renal ectopia at autopsy ranges from 1:7600 (Wilmer, 1938) to 1:1300 (Campbell, 1963). Crossed ectopia without fusion is much rarer and occurs in 10-15% of all crossed ectopic kidneys (Lee, 1949; Gray and Skandalakis, 1972), with only about 60 cases having been reported (Caine, 1956; Moshkowitz and Abrahamov, 1969). Very few cases of solitary crossed renal ectopy have been reported. Purpon (1963) reviewing the literature found eight cases, including his own. Since then at least two more cases have been reported (Tabriski and Bhisitkul, 1965; Weiss, et al., 1965). There seems to be a slight preponderance of this anomaly in males and the two kidneys are more often found on the right side (McDonald and McClellan, 1957). This was also found in our series. Crossed ectoNc kidney may
CROSSED RENAL ECTOPIA be discovered at any age, but is most frequently found in the third decade of life. We found no predilection of age period at the time of diagnosis in our patients. The embryological development of crossed renal ectopia is not clear, and several hypotheses have been put forward such as faulty development of the ureteric buds or vascular obstruction to the ascent of the permanent kidney (Abeshouse, 1947; Malek and Utz, 1970). However, factors other than mechanical ones may be involved as the renal anomaly is seen to be associated with congenital abnormalities in other organs. Neidhardt et al. (1967) mention a possible teratogenic factor acting at the mesoblastic stage in the early embryo, thus explaining anomalies in other mesoblastic formations such as the skeleton. The anomaly may be an incidental discovery. In symptomatic patients pain is the most frequent complaint, occurring on the side of the displaced kidney, and was noted to be present in seven of our cases. Dysuria and frequency of micturition are also mentioned as presenting symptoms, as are haematuria, pyuria and a palpable mass in the abdomen. In four of our patients, an abdominal mass was palpated. In the others, excretory urography was performed for a wide variety of symptoms and signs, such as hypertension (three cases), absence of ejaculation, haematuria following a road accident with trauma to the back, congenital anomalies in other organ systems, and urinary tract infection in children (see Table 1). A plain film of the abdomen may demonstrate an abdominal mass caudal to the kidney region and absence of a normal kidney shadow contralaterally. The diagnosis is usually established by excretion urography. With normal-functioning kidneys the excretory urogram will show both the collecting systems to be on one side. The crossed ectopic kidney is almost always the inferior one, and only in one of our cases was it the superior one (Case 17). The upper pole of the lower kidney is usually fused with the lower pole of the upper one. It is important to demonstrate either by excretory urography or by retrograde pyelography the ureter of the crossed ectopic kidney and to show that its insertion into the bladder is in its normal place. This helps the differentiation from duplex kidney with a contralateral non-functioning kidney. With non-fusion of the kidneys the ectopic kidney may be low in the pelvis and projected over the sacrum. Symptoms of abdominal pain in these patients may be due to excessive mobility of the ectopic kidney (Amesur, 1963) and a film in the upright position may help to demonstrate this mobility (patient no. 14; Fig. 5).
343
Cysto-urethrography should be performed as well, especially in children. Kelalis et al. (1973) found vesico-ureteral reflux in 14 out of 16 children with horseshoe or ectopic kidneys. These authors concluded that there is an abnormality at the ureterovesical junction which is responsible for the reflux. Of the five children in whom cysto-urethrography was performed in our series, bilateral reflux was demonstrated in three. In one of them the reflux disappeared after conservative treatment. It may be suggested that the reflux had been caused by infection of the bladder and subsided after the infection had cleared. One cannot exclude, however, the possibility of a congenitally incompetent valve mechanism at the uretero-vesical junction, perhaps due to a short intramural segment. With growth of the child this segment lengths and thus the ureterovesical junction becomes competent (Tanagho and Hutch, 1965). In one of the two children without reflux the ectopic kidney was dysplastic and not functioning. The blood supply to the kidneys was abnormal in all the patients, who underwent renal arteriography. No constant arterial pattern could be discerned, renal arteries taking off from the aorta as high as the D12 level and as low as the L 3 - 4 level as well as from the iliac arteries. It was of interest to note that even the arteries supplying the non-ectopic kidney arose from abnormal sites (Rubinstein et al., submitted for publication). It is not well known that patients with crossed renal ectopia may have anomalies in other organs. Malek et al. (1971) in a survey of 21 children with ectopic kidney, seven of which were crossed ectopic kidneys, found in 18 of them anomalies involving organ systems outside the genitourinary tract; 10 had skeletal anomalies, nine cardiovascular and seven gastrointestinal malformations. Kelalis et al. (1973) found such anomalies in 47 of 60 children who had renal ectopia and fusion, half of them involving the skeletal system. We found malformations in other organ systems in 11 of our patients. Two of them showed cardiovascular anomalies (Case 6 and Case 21), one had atresia of the anus and the others showed a variety of skeletal anomalies, most of them in the lumbar spine. The patient with single crossed ectopic kidney had osteopoikilosis. This finding is probably a coincidence as we have not found any reported cases of osteopoikilosis with renal anomalies nor any mention of this comparatively rare bone disorder in patients with crossed renal ectopia. Treatment in symptomatic cases of unfused crossed renal ectopia may be directed to nephropexy of the ectopic kidney and Diaz (1953) described such
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CLINICAL RADIOLOGY
a successful procedure. In our patient with the mobile unfused crossed ectopic kidney, the pain was not severe enough to warrant surgery and this kidney functioned normally on the excretory urogram. Also, repair is often impossible in these cases because of the anomalous vascularisation. Two o f our patients have undergone nephrolithotomy. One child underwent bilateral uretero-vesical reimplantation and another one cystostomy with drainage. In three patients nephrectomy o f the diseased crossed ectopic kidney was performed. It is most important, o f course, to demonstrate a normally functioning kidney if treatment is planned for a diseased crossed ectopic kidney. Abeshouse (1947) quotes five cases o f operative death due to inadvertent total nephrectomy performed in patients in w h o m the true nature o f the anomaly was not recognised prior to surgery.
REFERENCES Abeshouse, B. S. (1947). Crossed ectopia with fusion. American Journal o f Surgery, 73, 658-682. Amesur, N. R. (1963). Crossed renal ectopia. British Journal o f Urology, 35, 11-16. Boatman, D. L., Culp, D. A., Jr, Culp, D. A. & Flocks, R. H. (1972). Crossed renal ectopia. Journal o f Orology, 108, 30-31. Caine, M. (1956). Crossed renal ectopia without fusion. British Journal o f Urology, 28, 257-258. Campbell, M. (1951). Clinical Pediatric Urology, pp. 159, 353. W. B. Saunders Co., Philadelphia. Campbell, M. (1954). Urology, VoL 1, pp. 279-280. W. B. Saunders Co., Philadelphia and London. Diaz, G. (1953). Renal ectopy: report of a case of crossed ectopy without fusion, with fixation of kidney in normal
position by the extraperitoneal route. Journal of the International College o f Surgeons, 19, 158-169. Gray, S. W. & Skandalakis, J. E. (1972). Embryology for Surgeons, pp. 475-478. W. B. Saunders Co., Philadelphia. Kelalis, P. P., Malek, R. S. & Sagura, J. W. (1973). Observations on renal ectopia and fusion in children. Journal o f Urology, 110, 588 592. Lee, H. P. (1948). Crossed unfused renal ectopia with tumor. Journal o f Urology, 61, 333-339. Malek, 1L S. & Utz, D. C. (1970). Crossed, fused, renal ectopia with an ectopic ureterocele. Journal o f Urology, 104, 665-667. Malek, R. S., Kelalis, P. P. & Burke, E. C. (1971). Ectopic kidney in children and frequency of association with other malformations. Proceedings of the Mayo Clinic, 46, 461-467. McDonald, J. H. & McClellan, D. S. (1957). Crossed renal ectopia. American Journal o f Surgery, 83, 995-1002. Moshkowitz, A. & Abrahamow, A. (1969). Crossed renal ectopia without fusion. Harefuah, 77, 343-344 (Hebrew). Neidhardt, J. H., Bouchet, A., Morin, A., Theoleyre, J. & Feldman, D. (1967). Apropos des malformations associ6es ~t certaines anomalies et ag6nesies r6nales. Lyon Medical, 217, 1582-1590. Purpon, I. (1963). Crossed renal ectopia with solitary kidney: a review of the literature. Journal of Urology, 90, 13-15. Rubinstein, Z. J., Hertz, M., Shahin, N. & Deutsch, V. Crossed renal ectopia: angiographic findings in 6 cases (submitted for publication). Tabriski, J. & Bhisitkul, I. (1965). Solitary crossed ectopic kidney with vaginal aplasia: a case report. Journal of Urology, 95, 33-35. Tanagho, E. A. & Hutch, J. A. (1965). Primary reflux. Journal o f Urology, 93, 158-164. Weiss, R. M., Maloney, P. K. & Boland, G. A. (1965). Crossed ectopia of a solitary kidney. Journal o f Urology, 94, 320-322. Wilmer, H. A. (1938). Unilateral fused kidney: a report of five cases and a review of the literature. Journal o f Urology, 40, 551-571.
