Int Urol Nephrol (2008) 40:875–879 DOI 10.1007/s11255-008-9380-5
UROLOGY-ORIGINAL PAPER
Transarterial glue embolization in iatrogenic renovascular injuries Nuri Cagatay Cimsit Æ Feyyaz Baltacioglu Æ Ismet Cengic Æ _ Ihsan Nuri Akpinar Æ Yalc¸ın Ilker Æ Levent Turkeri
Received: 20 November 2007 / Accepted: 25 March 2008 / Published online: 24 April 2008 Ó Springer Science+Business Media B.V. 2008
Abstract Iatrogenic injuries of the intrarenal arterial system include pseudoaneurysms and fistulas. They can cause hematuria and life-threatening hemodynamic instability, and therefore should be treated promptly. Endovascular treatment is recommended for these cases due to its effectiveness. Among the different agents used for embolization, n-butyl-2cyanoacrylate (glue) has rarely been used. We present 15 patients with pseudoaneurysms and/or arteriovenous or caliceal fistulas who were treated by glue embolization. In our patient group, five had a history of percutaneous nephrolithotomy, six had renal biopsies, three had nephron-sparing surgery, and one had percutaneous nephrostomy. Glue embolizations were performed with the microcatheter technique. All patients were successfully treated, and all but one had excellent follow-ups. One patient suffered from disseminated intravascular coagulation secondary to transfusion and died after the procedure. We think glue embolization is a safe and effective treatment for this group of patients and present our experience along with the technical approach. N. C. Cimsit (&) F. Baltacioglu I. Cengic _ N. Akpinar I. Faculty of Medicine, Department of Radiology, Marmara University, Istanbul, Turkey e-mail:
[email protected] Y. Ilker L. Turkeri Faculty of Medicine, Department of Urology, Marmara University, Istanbul, Turkey
Keywords Biopsy Embolization Fistula Glue Iatrogenic Injury Kidney Pseudoaneurysm Renovascular Transarterial
Introduction Iatrogenic renovascular injuries are seen after percutaneous procedures such as biopsies, nephrostomies, and nephrolithotomies or after nephron-sparing partial nephrectomies. Although these injuries do not constitute a major part of clinical work, the ever-increasing number of interventional procedures performed in modern clinical practice increase the numbers of these complications. These injuries to the renovascular tree should be promptly detected and treated due to their potentially fatal outcomes. Injury to the intrarenal arterial system can cause an arteriovenous fistula and/or pseudoaneurysm [1–5]. Endovascular embolization is accepted as the recommended treatment of these lesions [2, 6, 7]. We report our experience in the treatment of these lesions by embolization using n-butyl-2-cyanoacrylate (glue) and discuss the technical approach.
Materials and methods A total of 15 patients were referred to our vascular interventional unit either by the urology or radiology
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departments. The clinical conditions of these patients were either hemorrhage causing unstable hemodynamic status or persistent gross hematuria requiring blood transfusions. All patients had a history of percutaneous renal procedures or nephron-sparing surgery as the cause for their clinical states. The percutaneous procedure group included percutaneous nephrolithotomy (n = 5), renal biopsy (n = 6), and percutaneous nephrostomy (n = 1). Three patients had nephron-sparing surgery. All patients were presented with a clear understanding of the procedure and possible risks. A written letter of consent was signed by all patients before the angiographic procedures. Vascular access was obtained via the right femoral artery in all patients. The renal artery on the side of the intervention was selectively catheterized using a 5F angled catheter. The position of the catheter was assured to be at the very proximal end of the renal artery so that the complete vascular tree including the capsular artery could be visualized. Non-ionic contrast media was used in all patients, and the dose was 8 ml of contrast media for every injection. The runs were finished after the renal vein was clearly visualized. Diagnostic images were carefully assessed for the presence of a vascular pathology. Localization of the lesion and the branch of the renal artery supplying the area of the lesion was outlined. When the decision for glue embolization was made, the system was prepared for the guiding catheter by exchanging the femoral sheath with a 6F introducer. The guiding catheter was connected to a high-pressure infusion set with a standard Y-connector. The infusion set contained 500 ml or 1,000 ml Mediflex (Isotonic NaCl saline solution, EczacibasiBaxter, Turkey) wrapped with a cuff that is inflated to 300 psi. Delivery of the saline through the Y-connector was controlled manually with a standard venous infusion set, and flow was kept around 10 ml/min. An Excelsior 1018 microcatheter (Boston Scientific, USA) was used for all embolizations. It was guided through the guiding catheter positioned at the proximal part of the renal artery. The microcatheter is neatly pushed into the branch supplying the lesion, using the micro-guidewire (0.014 in.) where necessary. In cases of complex vascular turns, the roadmap technique was used.
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Once the microcatheter was in place, glue was prepared. A 12.5% glue concentration was prepared by diluting with Lipiodol (Lipiodol Ultra Fluide, Guerbet, France). The mixture was transferred into a 2-cc luer lock syringe. The lumen of the microcatheter was flushed a few times with 5% dextrose solution to prevent polymerization before reaching the arterial segments. The hub of the microcatheter was also washed before the injection of the glue was started. The distal end of the microcatheter had to be visible in an ideally straight line to control the injection of the glue. Small pulses with continuous slow injection were applied, and any reflux covering the distal part of the microcatheter was closely monitored. Once the artery feeding the pseudoaneurysm or the arteriovenous fistula was filled with glue, approximately 30 s was timed to allow the polymerization of the material. The microcatheter was pulled swiftly in one rapid motion and taken out of the main catheter. The microcatheter was flushed thoroughly with dextrose solution immediately after being pulled out and prepared for re-use for further glue injections A control run was made via the guiding catheter, which was still at the proximal part of the renal artery, and the lesion was checked for vascular filling. If there was any residual filling, the procedure was repeated as described or ended if not. All patients were followed-up on an inpatient basis; hematuria and blood counts were closely monitored until all values stabilized. The description of the patient group, their lesions, and information about their treatment are presented in Table 1.
Results Diagnostic runs identified intrarenal pseudoaneurysm in seven patients, and arteriovenous fistulas accompanying a pseudoaneurysm were present in six patients. Caliceal fistulous filling from the arterial system was detected with pseudoaneurysms in two cases (Figs. 1 and 2). A total of 20 glue injections were performed in 15 patients. One patient needed two and two needed three injections until no pathologic vascular filling was observed.
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Table 1 Patient group characteristics and information about treatment Patient
Cause of injury
Type of injury
Number of injections
Technical successa
1
PNL
PA
1
Yes
2
PNL
PA
1
Yes
3
PNL
PA + AVF
1
Yes
4
PNL
PA + AVF
2
Yes
5
PNL
PA + AVF
1
Yes
6
RB
PA
1
Yes
7
RB
PA
1
Yes
8
RB
PA
1
Yes
9
RB
PA + AVF
3
Yes
10
RB
PA + AVF
1
Yes
11 12
RB PN
PA PA + CF
1 1
Yes Yes
13
NSS
PA + CF
1
Yes
14
NSS
PA + AVF
3
Yes
15
NSS
PA
1
Yes
PNL: Percutaneous nephrolithotomy, RB: renal biopsy, PN: percutaneous nephrostomy, NSS: nephron-sparing surgery, PA: pseudoaneurysm, AVF: arteriovenous fistula, CF: caliceal fistulous filling a
Total embolization of all lesions and no procedure-related complications
Embolization procedures were successful in all patients. There were no procedure-related complications. One patient with massive bleeding that stopped after the procedure developed transfusion-related disseminated intravascular coagulopathy 20 h after treatment and died. Hematuria and/or retroperitoneal bleeding was controlled in all other patients and hemodynamic status normalized within 24 h.
Discussion Transarterial embolization is an effective technique that can safely be used in major renal vascular injuries [2, 6–9]. It replaces emergency surgery, which is the only alternative in a patient with lifethreatening hematuria [2, 10]. The lesions responsible for hematuria in this group of patients are nearly always located in the distal branches of the renal artery. This necessitates the use
Fig. 1 Selective renal artery injection during early arterial phase; vascular lesion in the lower lobe of the kidney (a). Late phases of the same injection showing the well-delineated pseudoaneurysm (b). Control angiogram after embolization with glue; no filling in the lesion and preservation of the nearby distal vasculature (c)
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Fig. 2 Angiogram during arterial phase showing a pseudoaneurysm and early venous filling (a). Magnified view during later phases; note the increased lumen diameter due to increased flow and irregular contour of the pseudoaneurysm (b). Control angiogram after embolization showing complete obliteration of the fistula and pseudoaneurysm (c)
of microcatheters to effectively treat the lesions and minimize the loss of viable tissue [5, 11]. Different kinds of embolic materials have been reported to be
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used in renal artery embolization, namely polyvinyl alcohol particles (PVA), embosphere, gelfoam, coils, and glue [1, 10]. When embolization is performed with PVA, particles can form a plug inside the lumen of the microcatheter, causing the operator to apply excessive pressure and lose control of delivery. It is a very effective material for use with larger lumen catheters, but not as effective in our experience in the distal small branches of the renal artery. Gelfoam has been reported to be used with success [1]. It is absorbed a few weeks after the embolization long after the bleeding stops. Detachable coils are an alternative, but the small diameters of the distal branches usually do not allow the use of this material because the coils do not have enough space inside the lumen to reproduce their predefined shapes. They can be used in long-standing fistulas where the lesion and the feeding branch are much larger or as an additional measure at the proximal end of the area of embolization [1]. Another problem is the cost of these coils compared to glue, and this can be a deterring cause in their use. The administration of glue requires the operator to be well experienced. Glue polymerizes rapidly when it contacts blood or any other ionic tissue. The injection should be performed at a slow, but continuous pace to prevent early and abrupt polymerization. It is delivered as a mixture with the high viscosity liquid agent Lipiodol, helping the delivery to be far more controlled and evenly distributed. The operator should be very well acquainted with the behavior of the material and be ready to end the injection when risks arise. Glue can reflux to the parent artery during the procedure, and this can lead to a few problems. Embolization should be performed after reaching as distally as possible, since there is the possibility of reflux into a normal distal branch, and hence loss of more renal parenchyma. One should be cautious and closely monitor the progress of the material during the entire injection. If there is the risk of reflux into a normal artery, the procedure should be ended. Another problem with reflux is the embedding of the microcatheter tip inside the glue cast. If this occurs and the injection time is prolonged, the microcatheter can be trapped inside the polymer, making withdrawal impossible. If this is ever the case, one should never try to forcefully pull it to prevent serious vascular damage. The microcatheter can safely stay inside the vascular lumen with the proximal end cut and left in the
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subcutaneous tissue in the groin region. These risks necessitate these procedures to be applied by welltrained endovascular therapists. The polymerization process of n-butyl-2-cyanoacrylate is an exothermic reaction, and this causes destruction of the vessel wall and necrosis. This effect has been the main concern in using glue, but neither we nor other experienced teams have experienced any complications related to this. We think that by using glue as an embolizing material, ischemic necrosis is already an accepted result, and there should be no further tissue loss due to the local effect of glue. We needed to perform repeated glue injections in two patients. The microcatheter had to be flushed thoroughly with dextrose solution immediately after the injections to avoid polymerization of glue and occlusion of the microcatheter lumen. This part of the procedure is very important to minimize the cost and if neglected, every injection should be made with a new microcatheter. Glue has been used in the treatment of cerebral and spinal arteriovenous malformations with success for years. The teams using glue for neurovascular interventions have been asked and are willing to make use of it in other areas where embolization is needed. Renal arterial hemorrhage can be seen as an extension for glue embolization. We strongly believe glue embolization is a safe and effective treatment in cases of life-threatening hematuria, and it represents a fairly low-cost treatment with a very high rate of success in experienced hands.
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