**7. Other complications following renal transplantation**

#### **7.1. Malignancy after kidney transplantation**

In general, pseudoaneurysms develop secondary to biopsy injury. Most of them resolve spontaneously within the first two months. However, if there were progressive enlargement, an unusual size (> 2 cm in diameter) or loss of renal function, intervention will be required [31]. US shows a simple or complex cyst. CD shows the to-and-fro yin and yang pattern seen in

**Figure 18.** (A): MRA reconstructed with MIP nicely demonstrates the renal artery stenosis (arrow). (B): DSA of a differ‐ ent case showing multifocal stenosis in the renal artery (arrows) and a long segmental stenosis in the polar artery (ar‐

(A)

46 Current Issues and Future Direction in Kidney Transplantation

(B)

rowhead).

It is a known fact that patients submitted to renal replacement therapy, whether dialysis or transplantation, are at higher risk for cancer [88]. Among neoplasias, urologic tumors are about 4 to 5 times more frequent among renal transplant recipients and their characteristics differ

Algorithm for imaging evaluation of complications after kidney transplantation NM – nuclear medicine US – ultra sound

**Figure 20.** Algorithm for initial evaluation of kidney transplantation.

from those of tumors occurring in the general population. These neoplasias show three different presentations: de novo occurrence in the recipient, recurrence of a preexisting malignant neoplasia, or transfer of a malignant neoplasia together with the renal graft [89].

presentation of recurrence includes early massive proteinuria and sometimes graft failure and arterial hypertension [96]. Imaging has no specific pattern in these situations, and mainly plays

**Figure 21.** Vesical neoplasia in patient with renal allograft. A mass is seen in the bladder floor (arrow). Transplant kid‐

Imaging in Kidney Transplantation http://dx.doi.org/10.5772/55074 49

Nonfunctional renal grafts are often left in situ. As in chronic native renal parenchymal chronic disease the grafts are usually small, and can have fatty replacement, hydronephrosis, infarcts,

Focal lesions are seen as a less common complication after transplantation. Besides parenchy‐ malabscess,andfocalinfarction,thesemaybesecondarytorecentsurgerysuchasfocalcontusion or postbiopsy intrarenal hematoma. Focal lesions may be miscarried in surveillance [33].

The number of people waiting for transplantation using cadaveric organs is usually very expressive, worldwide. Therefore kidney transplantation from living donors is becoming more and more frequent. Living donor kidney recipients have a significant increase in graft survival compared to deceased donor recipients. A living donor transplant has the advantage not to require a waiting list and can be performed in a preemptive manner (before the beginning of

a role in guiding biopsy.

ney (TK) is in left inguinal fossa.

**7.3. End-stage disease**

**7.4. Renal focal lesions**

**8. Donors' evaluation**

hemorrhage, and calcifications [19].

With increasing donor age, the use of marginal donors and the increased survival of renal grafts, malignant genitourinary neoplasms have become more common. Thus, post-renal transplant vigilance is important in order to obtain an early diagnosis and to institute appro‐ priate treatment (Figure 21).

The imaging methods used for diagnostic confirmation are those cited earlier and their use varies according to the symptoms presented by the patient.

#### **7.2. Disease recurrence**

Disease recurrence in the graft has a greater prevalence in children than in adults, thereby increasing patient morbidity, graft loss and, sometimes, mortality rates. Indeed, the current overall graft loss is mainly due to primary glomerulonephritis (70–80%) and inherited metabolic diseases [7, 90-95]. It depends on the primary disease before transplantation. The

**Figure 21.** Vesical neoplasia in patient with renal allograft. A mass is seen in the bladder floor (arrow). Transplant kid‐ ney (TK) is in left inguinal fossa.

presentation of recurrence includes early massive proteinuria and sometimes graft failure and arterial hypertension [96]. Imaging has no specific pattern in these situations, and mainly plays a role in guiding biopsy.

#### **7.3. End-stage disease**

Nonfunctional renal grafts are often left in situ. As in chronic native renal parenchymal chronic disease the grafts are usually small, and can have fatty replacement, hydronephrosis, infarcts, hemorrhage, and calcifications [19].

#### **7.4. Renal focal lesions**

from those of tumors occurring in the general population. These neoplasias show three different presentations: de novo occurrence in the recipient, recurrence of a preexisting malignant neoplasia, or transfer of a malignant neoplasia together with the renal graft [89]. With increasing donor age, the use of marginal donors and the increased survival of renal grafts, malignant genitourinary neoplasms have become more common. Thus, post-renal transplant vigilance is important in order to obtain an early diagnosis and to institute appro‐

The imaging methods used for diagnostic confirmation are those cited earlier and their use

Disease recurrence in the graft has a greater prevalence in children than in adults, thereby increasing patient morbidity, graft loss and, sometimes, mortality rates. Indeed, the current overall graft loss is mainly due to primary glomerulonephritis (70–80%) and inherited metabolic diseases [7, 90-95]. It depends on the primary disease before transplantation. The

priate treatment (Figure 21).

NM – nuclear medicine US – ultra sound

**7.2. Disease recurrence**

varies according to the symptoms presented by the patient.

Algorithm for imaging evaluation of complications after kidney transplantation

**Figure 20.** Algorithm for initial evaluation of kidney transplantation.

48 Current Issues and Future Direction in Kidney Transplantation

Focal lesions are seen as a less common complication after transplantation. Besides parenchy‐ malabscess,andfocalinfarction,thesemaybesecondarytorecentsurgerysuchasfocalcontusion or postbiopsy intrarenal hematoma. Focal lesions may be miscarried in surveillance [33].
