13 Embolization Therapy for High-Flow Priapism
Jim A. Reekers
J. A. Reekers, MD, PhD
Department of Radiology, G1-207, Academic Medical Center, University of Amsterdam, Meibergdreef 9, AZ 1105 Amster- dam, The Netherlands
The clinical presentation of these two types of priapism is different. HFP is often seen after an acute injury, and the onset can be delayed. This delayed onset may be due to initial vessel spasm, hemostasis with clot formation or a compressing hematoma. Reabsorption of this clot or hematoma is the mechanism for the late onset. The HFP is often less tumescent when compared with venous pria- pism. Priapism secondary to arterial causes may be, as mentioned before, significantly less painful than venous priapism and is not considered as an emer- gency. The major etiology of HFP is trauma, espe- cially in children or young adults; in older men, HFP is a rare event mainly caused by malignancy [2].
High-flow priapism in acute lymphatic leukaemia has also been reported [3].
Veno-occlusive priapism presents with a pain- ful erection, which can already have been there for days. Prolonged veno-occlusive priapism results in fibrosis of the penis and a loss of the ability to achieve an erection. Significant changes at the cel- lular level are noted within 24 h in veno-occlusive priapism, whereas arterial priapism is not associ- ated with fibrotic change. Veno-occlusive priapism most commonly is idiopathic, although there is a long list of other causes which include leukemia and multiple myeloma, sickle cell disease, thalassemia, spinal cord injury, spinal anesthesia and drugs.
13.2 Diagnosis
Careful patient history and clinical signs and symp- toms are of paramount importance. As stated pre- viously, history of trauma with a painless priapism favors HFP. Cavernous blood coloration and gas measurement are very useful and easily available to distinguish between HFP and venous priapism.
A bright red appearance of the cavernous blood is more in favor of HFP, which in turn is associated with a high po2 and low pco2. General diagnostic
CONTENTS
13.1 Introduction 227 13.2 Diagnosis 227 13.3 Imaging 228 13.4 Therapy 228
13.5 Embolization Therapy 228 13.6 Technique of Embolization 228 13.7 Follow-up 230
13.8 Conclusion 231 References 231
13.1
Introduction
Priapism is named after the Greek god, Priapus, son of Aphrodite and Dionysus.
Priapism is a persistent erection of the corpora cavernosa of the penis, originating from distur- bances to the mechanisms that control penile detu- mescence. This affects only the corpora cavernosa.
The corpora spongiosum of the glans penis and sur- rounding the urethra are not part of the process.
The overall incidence of priapism is 1.5 per 100000
person-year [1]. Priapism is broadly classified as
high-flow and low-flow. Arterial high-flow pria-
pism (HFP) is usually secondary to the laceration of
a cavernous artery with unregulated flow into the
lacunar spaces. This type of priapism is most of the
times not painful because there is no ischemia. HFP
is rare and only 200 cases have been reported in the
literature. Nonetheless, because it is painless, it is
possible that HFP is under reported. The other type
is veno-occlusive priapism which is usually caused
by corporeal veno-occlusion, and can be very pain-
ful due to ischemia.
tests include complete blood count, platelets, differ- ential white blood cell count and reticulocyte count and urine analysis for drugs.
13.3 Imaging
Penile ultrasound and Doppler testing may be neces- sary to differentiate high-flow from low-flow pria- pism. In HFP, ultrasound reveals an hypoechoic, well-circumscribed region in the corpus caverno- sum. The Doppler will show an increased flow in the penile artery, uni-or bilateral, and an arterio- cavernosal fistula (Fig. 13.1). In patients with high- flow priapism, selective penile angiography may be required in order to identify the site of the fistula.
Angiography should however not be done as a diag- nostic procedure, but always in combination with a planned therapeutic embolization.
13.4 Therapy
The goal of all treatment is to treat the priapism while preserving future erectile function. This paper will only discuss the treatment options in HFP.
There are some alternative treatment options for high-flow priapism, like ice packs where ice is applied to the penis and perineum to reduce swell- ing, corporal aspiration, massage, and pressure dressings. Pharmacological interventions are also used. This includes the use of alpha-agonists (e.g., metaraminol bitartrate) or methylene blue. Alpha- agonist agents counteract smooth muscle relax- ation. However, they may cause significant systemic hypertension. Methylene blue inhibits guanylate cyclase and has a second messenger inhibitory effect; thus, it inhibits smooth muscle relaxation.
The effect of methylene blue is relatively short-lived, and priapism may recur. Any of these treatment options are often of little use in high-flow priapism, as a rupture of the artery does not subside spontane- ously. Surgical ligation of the fistula is an operation which is redundant now that embolization is widely used; however it is still performed. One of the main potential complications of this procedure includes long-term impotence. For HFP caused by inherited diseases, and malignancy conservative therapy is mandatory.
13.5
Embolization Therapy
The blood supply of the penis derives from the internal pudendal artery (IPA). The common penile artery is a distal branch of the IPA and gives rise to the bulbourethral artery at the base of the penis, subsequently dividing into the dorsal penile and cavernosal arteries. The anatomy of the internal pudendal artery has many variations, but usually comes from the anterior division. The most common presentation is shown in Fig. 13.2. One has to take in consideration that the inferior rectal artery derives from the IPA, which off course prevents selective embolization from the origin of the IPA with a flow guided embolic agent like particles as they will end also in the rectal mucosa. However, when a selective position cannot be achieved, proximal coil emboli- zation in the IPA might be performed (Fig. 13.3). In high-flow priapism one can see arteriovenous fistu- las or pseudoaneurysms, resulting in abnormal arte- rial inflow, which exceeds venous outflow capacity, resulting in tumescence. Fistulas can be uni-lateral or bilateral, and to achieve optimal results, all fis- tulas should be occluded (Fig. 13.4) [4, 5].
13.6
Technique of Embolization
In our experience contra lateral access, over the aortic bifurcation, gives the best stability and free- dom of movement for selective catherization. If the
Fig. 13.1. Ultrasound with Doppler in a patient after a bicycle trauma. Doppler shows high systolic velocity of 73 cm/s. Color Doppler demonstrates a fi stula (black arrow) within a well-cir- cumscribed hypoechoic hematoma or laceration in the corpus cavernosum.
Fig. 13.2. a The most common anatomy of the internal pudendal artery origin. b Selective catheterization of the internal pudendal artery with distal division into the deep and dorsal branch
a b
Fig. 13.3. Embolization of both internal pudendal arteries with coils in a patient with priapism and sickle cell disease. The aim of this treatment was to create permanent impotence and to prevent fi brosis
fistulas are bilateral we start with a 5 F sheath in both common femoral arteries. The internal iliac artery is selectively catheterized with a multi-purpose tip catheter. A firmer catheter allows a more stable posi- tion where a glide-catheter might not have enough stability to act as a guiding for a micro-catheter.
Diagnostic angiography is performed to establish the diagnosis and to guide the superselective embo- lization. A microcatheter 18" with a 14" floppy wire is used to position the tip of the microcatheter in/at the side of the fistula. The position has to be as selec- tive as possible to warrant erectile function after the procedure (Fig. 13.3). Spasm might be a problem, therefore local spasmolytics, like nitroglycerin, can be applied before selective catheterization. Systemic spasmolytic support, such as ca-blockers, can also be helpful. If the patient is using anticoagulant med- ication, this should be stopped, but only after con- sultation of the primary physician.
Embolotherapy for high-flow priapism has been accomplished using a variety of agents including autologous clot, gelatin sponge pledgets, bucrylate and microcoils. It seems to be rational to advo- cate the use of temporary occlusive agents, such as autologous clot or gelatin sponge, to allow eventual recanalization and to preserve sexual function.
However, in the literature it is shown that also more permanent agents show preservation of sexual func- tion.
When the microcatheter tip has a superselective position in/at the fistula we prefer to use a microcoil because this allows the most precise local occlu-
sions without an inadvertent occlusion of nontarget
branches. If we are not able to achieve this optimal
position and stop in a more proximal position, we
will use gelatin sponge but only with the catheter
tip distally to the inferior rectal artery branch. We
never use glue as, in our opinion, the delivery is
Fig. 13.4a–f. Posttraumatic HFP with bilateral fi stulae. a Left internal iliac artery angiography shows a fi stula. b Selective left IPA. c After closure of the fi stula with gelatin sponge. d Selective right IPA shows a second fi stula. e Microcatheter in superse- lective position. f End result after embolization with gelatin sponge. Patient had a full recovery and regained normal erectile function
b
d
f
a c
e
never fully under control in this delicate area. Sec- ondly, after glue delivery the microcatheter has to be removed and in case of a residual arteriovenous fis- tula selective catheterization has to be started again.
However, successful glue embolization of HFP has already been reported [6].
After uni- or bilateral occlusion of all the fistula(s) has been achieved, the catheters and sheaths are removed. A color Doppler control after 24 h should be performed to document the local result. Although postembolization recurrence has been reported as
high as 20%, it is lower in most publications, and not related to the embolic agent used [7].
13.7 Follow-up
Usually within hours after the embolization the pri-
apism will be resolved. For normal erectile function
to restore it might take up to 6–9 months [7]. As
Cookbook
Introduction 5-F sheaths Any
Guiding Multipurpose 5-F
(No glidecath)
Any
Guide wire Terumo wire 35’ Terumo
Selective catherization Microcatheter 18’’+14’ wire Target (Boston Scientific) Embolization material Gelatin sponge or coils Cordis/Boston Scientific/Cook
“normal” can be an subject of discussion an objective test like the International Index of Erectile Function (IIEF) should be used in follow-up. According to this test 80% of all patients will regain normal erectile function, while 20% will have a slight change in the quality of erection [7].
One of the concerns of embolization treatment is the local radiation of the gonads. Reduction of radi- ation can be achieved with the combined approach of X-ray and ultrasound imaging to facilitate the supraselective embolization of the arteriocavern- ous fistula reducing the radiation exposure and the applied dose of contrast medium [8]. It seems ratio- nal to advise refrainment from reproductive activ-
ity for a period of at least 3–6 months, although this recommendation is not supported in the literature.
13.8 Conclusion
Embolization for HFP is currently the treatment of choice if conservative therapy fails. It is safe and effective with a very high success rate and also a high recurrence of erectile function. Super-selective catheterization is mandatory. Microcoils and gelatin sponge are the embolic agents of choice.
References
001. Eland IA, van der Lei j, Stricker BH, et al. (2001) Inci- dence of priapism in the general population. Urology 57:970
002. Kuefer R, Bartsch G Jr, Herkommer K, Kramer SC, Klein- schmidt K, Volkmer BG (2005) Changing diagnostic and therapeutic concepts in high-flow priapism. Int J Impot Res 17:109–113
003. Mentzel HJ, Kentouche K, Doerfel C, Vogt S, Zintl F, Kaiser WA High-flow priapism in acute lymphatic leukaemia.
Pediatr Radiol 34:560-563
004. Gorich J, Ermis C, Kramer SC, Fleiter T, Wisianowsky C, Basche S, Gottfried HW, Volkmer BG (2002) Interven- tional treatment of traumatic priapism. J Endovasc Ther 9:614–617
005. Langenhuijsen JF, Reisman Y, Reekers JA, de Reijke Th M (2001) Highly selective embolization of bilateral cavern- ous arteries for post-traumatic penile arterial priapism.
Int J Impot Res 13:354–356
006. Gandini R, Spinelli A, Konda D et al. (2004) Superselective embolization in posttraumatic priapism with Glubran 2 acrylic glue. Cardiovasc Intervent Radiol 27:544–548 007. Savoca G, Pietropaolo F, Scieri F, Bertolotto M, Mucelli FP,
Belgrano E (2004) Sexual function after highly selective embolization of cavernous artery in patients with high flow priapism: long-term followup. J Urol 172:644–647 008. Bartsch G Jr, Kuefer R, Engel O, Volkmer BG (2004) Pria-
pism: colour-Doppler ultrasound-guided supraselective embolization therapy. World J Urol 22:368–370
