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Paper text:
historically , kidneys with congenital abnormalities were often discarded because of the perceived risk of technical complications .  
however , as the waiting times for kidney transplants continue to increase , transplant centers have become more aggressive at using select kidneys with congenital abnormalities .  
horseshoe kidneys are now routinely used for transplantation , either as a single or split graft .  
renal ectopia describes the failure of the kidney to ascend and cross the midline during development , resulting in the ipsilateral position of both kidneys .   in many cases they remain fused .  
although these kidneys have an increased rate of vascular and ureteral anatomical anomalies , there are select reports of use in renal transplantation .   
this is the first case report of the successful transplantation of a split crossed fused kidney for a combined simultaneous kidney pancreas transplantation .
the transplant recipient is a 58-year - old female who developed type i diabetes mellitus at 6 months old and used an insulin pump for blood sugar control .  
she developed end organ damage including renal failure but was not yet dialysis dependent .   
she did not have hypoglemic unawareness and had good blood sugar control with her insulin pump .  
she was approved and listed for combined simultaneous kidney pancreas transplantation .   at the time of transplantation her panel of reactive antigen ( pra ) was 0% and there were no identifiable hla specific antibodies .  
the donor was a 31-year - old male motorcyclist who collided with a concrete medium at highway speed .  
the donor did not have significant past medical or surgical history , except for smoking cigarettes and occasional marijuana .  
the donor family was not aware of his congenital renal anomaly and the patient did not have other congenital anomalies .  
a computed tomography ( ct ) scan of the abdomen done at the time of admission revealed an ectopic right kidney located in the pelvis and fused with the lower pole of the left kidney , compatible with crossed fused renal ectopia ( figure 1 ) .  
the serum creatinine peaked at 1.8 and was 1.4 at the time of procurement .  
the procurement of the kidneys , pancreas , and liver was completed in the standard fashion , flushing with custodial htk ( odyssey ) solution .  
the upper and mid polar arteries of the right kidney originated from the aorta , while the lower pole artery originated from the right common iliac artery .  
there were single renal veins bilaterally , which drained into the inferior vena cava .  
the left ureter crossed the midline and entered the bladder in the normal anatomic position .
the back table dissection and parenchymal transection was completed with the assistance of the urology service .  
initially we had planned to split the kidneys and use each singly for transplant ( figure 2 ) .  
however , the right kidney was abnormal in appearance ; in particular it was very thin .  
the mid and lower pole arteries were very small and were not connected to the aortic patch , making them difficult to reimplant .
we elected not use the renal mass en bloc , due to the complex arterial anatomy , including the number , caliber , and configuration .   at that time
the right kidney was split from the left , carefully transecting the isthmus using sharp dissection .   a few vessels and what appeared to be a small calyx were suture ligated with vicryl suture .   next , the transection plane was closed using interrupted 0 chromic mattress sutures .  
pledgets of fat were used to prevent any cut through of the sutures through the parenchyma ( figure 3 ) .  
the kidney was anastamosed to the external iliac artery and vein on the left side .  
the kidney reperfused well , with minimal bleeding after reperfusion needing only bipolar coagulation for control .  
the pancreas graft was anastamosed to the right common iliac artery and vein and the donor duodenum to the recipient jejunum .  
immunosupression included campath induction , with prograf , cellcept , and a rapid steroid taper .
a protocol pancreatic biopsy at one year demonstrated drachenberg grade iii out v acute rejection .  
she is now 2 years posttransplant with normal pancreatic ( fasting blood sugar 86 , c - peptide 2.1 , hemoglobin a1c 5.4 ) and renal graft function ( creatinine 1.0 and creatinine clearance 55 ) .
the continuing shortage of deceased donor kidneys has inspired transplant programs to search for innovative ways to increase the number of potential donor kidneys .  
it is now common for many centers to use en bloc pediatric kidneys , kidneys with acute renal failure , and two extended donor criteria kidneys in a single recipient [ 13 ] .  
horseshoe kidneys are now routinely used as both dual and split single transplants , with results almost equivalent to deceased donor transplantation ( 83.3% graft survival at 5 year follow - up ) .
the recent case reports describe the use of living donors and in situ split of the horseshoe kidney for transplantation .
congenital renal fusion anomalies are seen in 1 in 250 autopsies , with horseshoe kidney being the most common anomaly present in 1 to 600800 adults .  
renal ectopia has an incidence of 1/5001200 and the ectopic kidney can be located from the pelvis ( most common ) to the thorax .
the combination of ectopia and fusion can be found at an incidence of 1/1000   and is termed crossed fused renal ectopia ( cfre ) .  
although there are 6 described variations of cfre , the aberrant kidney is most often located inferior to the normally positioned kidney , and fusion occurs between the superior pole of the aberrant kidney to the inferior pole of the normal kidney .
most patients remain asymptomatic , and the diagnosis is made at the time of autopsy or imaging done for another indication .  
however , ureteral obstruction , renal calculi , and an increased risk of neoplasm have all been described .
there is a single case report of transplantation with a nonfused kidneys   and two case reports of crossed as a dual transplant [ 8 , 10 ] .
this is the first report of splitting the crossed fused renal ectopia prior to transplantation as well as in combination with a simultaneous pancreas transplant .  
cfre may be diagnosed preoperatively on routine imaging or intraoperatively at the time of donation .  
donors with a history of renal calculi or recurrent urinary tract infections in combination of crfe should be excluded because of the potential for postoperative obstructive complications .
familiarity with the potential anatomic anomalies associated with crfe is essential to prevent injury to the kidneys at the time of procurement .  
more than 70% of crfe have multiple arteries and multiple veins are also common .  
it is optimal for the kidneys to be procured en bloc , with consideration for transection done at the recipient transplant center .  
unlike with horseshoe kidneys where the ureters are located anteriorly in a normal anatomic position , ureters from the crossed fused ectopic kidney crosses over the midline to left side to enter in the bladder in a normal anatomic position .  
care must be taken to avoid ureteral transection , especially during the contra - lateral iliac dissection .
investigation of the kidneys should be on the back table to consider for possible split .  
obviously , obtaining two grafts is preferable to using one , but it may not be possible secondary to anatomic anomalies .   both the aberrant and normally positioned kidney   can have variant arterial supply from the upper abdominal aorta , lower aorta , and iliac arteries .  
if the number or size of the arteries is too complex for transplantation , splitting of the ectopic moiety ( as in our case ) or en bloc transplantation   is recommended .   in our case ,
if multiple renal veins are encountered during routine transplantation , most surgeons routinely ligate smaller renal veins without affecting the outflow of the kidney
.   however , in these cases there may not be collateral venous drainage between the two kidneys and anastamosis of even smaller veins may be necessary to prevent venous hypertension .
horseshoe kidneys and cfre are separated by a tissue band , which ranges from a thin fibrous isthmus to thick functional parenchyma .  
the techniques used for renal transection in partial nephrectomies are applicable to the back table splitting the fused kidneys .  
this includes sharp transection followed by use of the tissue link or cautery for hemostasis , as well as direct locking suture ligature of the stump .  
in addition , the use of hemostatic glues and materials can be used to help attain hemostasis and prevent a urine leaks .   in this case , the isthmus was thin and a sharp transection followed interlocking suture closure of the defect in combination with peri - renal fat pledgets was sufficient to prevent both hemorrhage and urine leak .  
if the bridge of tissue is too thick to allow safe transection , the kidney can be transplanted as a single graft or en bloc .
the last consideration is that the crfe kidney may be difficult to position due to the vascular reconstruction and increased renal mass .   as pointed out by bailey et al .
, opening of the peritoneum for positioning may be necessary if the transplant is completed through an extra - peritoneal approach .   in this paper
, the kidney was placed intraperitoneal and secured behind the sigmoid colon to prevent torsion .  
although the use of a living donor split horseshoe kidney has been reported in the literature , the complex vascular and arterial anatomy , as well as potential compromise of the donors remaining kidney , would make living donation treacherous .
however , the kidneys must be both procured and transplanted with careful attention to the anomalous vascular and ureteral anatomy , as well as graft placement to prevent torsion .  
if there are multiple vascular structures , or the transaction plane does not result in adequate nephron mass for both kidneys , consideration of transplanting the kidneys en bloc or resection the smaller moiety should be considered .  
transplant surgeons should be familiar with these potential anatomic variations to ensure these grafts are not wasted .  
long term graft survival does not appear to be limited in these otherwise healthy donor kidneys .
potential donors with congenital renal anomalies but normal renal function are often overlooked because of a possible increase in technical difficulty and complications associated with the surgery . however , as the waiting list for a deceased donor kidney transplant continues to grow , it is important to consider these kidneys for potential transplant . 
 this paper describes the procurement of a crossed fused ectopic kidney , and subsequent parenchymal transection prior to transplantation as part of a combined simultaneous kidney pancreas transplant . 
 the transplant was uncomplicated , and the graft had immediate function . 
 the patient is now two years from transplant with excellent function .