CT Cavernosography: An Institutional Experience

Mohanned A Alnammi MD 1, Andrew McCullough MD 2, Jared Schober 2, James Trussler MD2 , Sarah Ali MD 1, Jeremy Wortman MD 1, Sebastian Flacke MD 1 Lahey Hospital and Medical Center, Department of Radiology 1 Lahey Hospital and Medical Center, Department of Urology 2 Nothing to Disclose Objectives ● Present our institutional protocol for Penile Cavernosography ● To review

Ø Normal penile anatomy

Ø Variations in venous leakage and radiological anatomy

Ø Penile disorders including corporal fibrosis, priapism, peyronie’s disease and implant complications Target audience ● Genitourinary Radiologist ● Urologist Introduction/Background -1-

● The Massachusetts Male Ageing Study reported a prevalence of mild to moderate Erectile dysfunction (ED) in 52% of men aged 40- 70 years and strongly correlated with age, health status and emotional function.

● ED in most cases was thought to be psychogenic but current evidence suggest that more than 80% are organic.

● ED is broadly divided into endocrine and non-endocrine causes. Non-endocrine causes include arterial insufficiency, abnormal venous outflow (Corporal veno-occlusive disease), neurogenic, and iatrogenic (Radical prostatectomy most common). Introduction/Background -2-

● Peyronie’s disease (PD) is characterized by fibrotic connective tissue within the tunica albuginea, with ED present in 20-50% of men suffering from PD. The most widely accepted pathophysiological hypothesis (Devine et al) is repetitive trauma to the erect penis during intercourse.

● Wespes et al in 1984 established that impotence is not only due to arterial factors but also influenced by venous system dysfunction. In corporal fibrosis, there is a decrease in content or function of the corporal smooth muscles cells which predisposes to the development of corporal veno- occlusive disease (VOD).

● Cavernosography (conventional fluoroscopy or CT cavernosography) remains the diagnostic standard for the diagnosis of venous leakage. Protocol for CT Cavernosography

1. Equipment/medications: 60 ml syringe for contrast and normal saline, 100U diabetic syringe for Trimix(#8 or #13), Lidocaine 1%, 20 gauge angiocatheter.

2. Injection: Lidocaine 1% is injected subcoronal, trimix given by intra- cavernosal injection. A 20-gauge angiocatheter is placed in the left corpus cavernosum. 50% diluted contrast (1:1 ratio of contrast and normal saline) is injected through the angiocatheter until erection is achieved.

3. CT scan: cranial-caudal direction to include the entire penis, 120kV, 185 – 350 mA (according to body size), slice thickness 1 mm. Multiplanar reformats and 3D volume rendering. Penile Anatomy Penile Anatomy

Venous system Arterial system Classification of Venous Leakage 5 ● Superficial venous leakage (Superficial external pudendal , Corpus spongiosum) ● Deep venous leakage (Internal pudendal vein, Obturator vein) ● Mixed superficial and deep venous leakage (Both superficial and deep venous leakage)

Superficial venous leakage Deep venous leakage Mixed superficial and deep venous leakage Superficial Venous Leakage 66 yo with prior radical prostatectomy and erectile dysfunction on high dose (60 units) intra-cavernosal trimix injections.

(a-b) 3D reconstruction shows left greater than right superficial external pudendal vein opacification (a: red arrows) originating from the superficial dorsal vein (b: yellow arrowhead) and corpus spongiosum (a: a b yellow arrow).

(c) Axial reformat shows the left superficial external pudendal vein draining into the left great saphenous vein (red arrows).

(d) Coronal reformat shows the bilateral superficial external pudendal vein (red arrowheads). c d Corpus Spongiosum (Caverno-spongious) Leakage

59 yo with erectile dysfunction. Failed PDF-5 inhibitor and on high dose (30 units) of intra-cavernosal trimix injection.

(a) 3D reconstruction shows superficial (red arrows) and deep ( red arrowheads) venous leakage with a predominant superficial venous leakage. a b (b) Coronal reformate of opacified corpus spongiosum (green arrow) with leakage via superficial external pudendal (green c d arrowheads).

(c-d) Axial reformate demonstrating bilateral superficial external pudendal vein leakage (c: yellow arrows) and draining into the bilateral great saphenous veins (d: yellow arrowheads) Deep Venous Leakage (Obturator vein)

66 yo with erectile dysfunction unresponsive to oral PDE 5 inhibitor.

(a-b) 3D reconstruction demonstrate opacification of the deep dorsal vein (a: red arrow) and the bilateral (b: yellow arrow). a b

(c-d) Coronal reformate demonstrate opacification of the prostatic plexus (c: red arrow) originating from the deep dorsal vein and leakage through the bilateral obturator veins (c: red arrowheads, d: yellow arrowheads).

c d Deep Venous Leakage (Internal pudendal vein)

58 yo with erectile dysfunction and prior history of urethroplasty due to bulb- membranous urethral stricture.

(a) 3D reconstruction demonstrate opacification of the bilateral (red arrows)

(b) Sagittal reformate shows a opacification of the deep dorsal vein, origin of the leakage (red arrow)

(c)Axial reformate demonstrate leakage through the prostatic plexus (yellow arrow) and the bilateral internal pudendal veins (red arrowheads) b c Visualization of the Cavernosal Penetration

Left corpus cavernosum Right corpus cavernosum Right corpus cavernosum

Figure 1: Left corpus Figure 2: Right cavernosal Figure 3: A more distal cavernosum demonstrate artery penetration through cavernosal artery penetrating penetration of the cavernosal the proximal corpus through the right corpus artery proximally (red arrow) cavernosum (red arrow) cavernosum (red arrow)

* The utility of this finding for pre-surgical planning is yet to be determined/analyzed. Penile Pathologies

● Corporal fibrosis

● Priapism

● Penile deviation and Peyronie’s disease

● Implant complications Corporal Fibrosis • Pathophysiology: Corporal fibrosis is characterized by a decrease in content and function of smooth muscle cells. Pro-fibrotic cytokines promote collagen deposition, replacing smooth muscle cells and results in decreased elasticity of the penis. This compromises the ability of the corpora cavernosa to compress sub-tunical veins leading to corporal veno- occlusive disease.

• Causes: 1. Peyronie’s disease 2. Post-removal of infected penile implant and penile trauma 3. Prolonged priapism 4. Intra-cavernosal injection of erectile dysfunction medications (Trimix) Corporal Fibrosis: Physical exam and Color Doppler evaluation

41 yo presents with discomfort/numbness of the distal shaft of the penis on erection and associated with decrease length. No erectile dysfunction or history of trauma.

a b Figure 1: (a-b) Physical examination showed a palpable 2cm plaque at the dorsum of the penis extending to the right lateral aspect with a leftward mild deviation (10-30 degrees). Color Doppler US (not shown) showed a normal peak systolic velocity and no calcified plaque identified. Underwent CT- Cavernosography for further evaluation. c: Left corpus cavernosum

a b

Figure 2:

(a-b) 3D reconstruction demonstrate non-opacification of the right distal corpus cavernosum (green arrows). d: Right corpus cavernosum (c-d) Sagittal projections comparing the left (c) with the right (d) corpora cavernosa. The right shows non-opacification of the distal and mid 1/3 of the corpus cavernosum (d; red arrows). Suggestive of severe corporal fibrosis. Patient underwent penile implant. Corporal Fibrosis Grading

Mild: Heterogeneous opacification Moderate: Pronounced decreased Severe: Non-opacification of of the corporal body or bodies opacification of the corporal body or bodies the corporal body or bodies a a a

b b b

Figure 1: (a-b) Bilateral proximal Figure2: (a-b) Demonstrate moderately Figure 3:(a-b) Non-opacification of the corpus cavernosum heterogeneous decreased opacification of the left corpora right corpora compared to the left (red decreased opacification (red circles) compared to the right (red arrows) arrowheads) Recurrent Priapism 32 yo with 3 weeks of recurrent priapism associated with pain. Visited the ER 4 times and responded to phlebotomies and phenylephrine. No prior trauma. Patient reports excessive masturbation (2 times/day). Ultrasonography was normal and no evidence of high flow or low flow (ischemic) priapism. Underwent penile angiogram to evaluate for arteriovenous shunt.

a b c

Figure 1 Penile angiogram: (a) Engagement of left (red arrow). Patent left (b) and right (c) dorsal (b-c: red arrowheads) with patency of the penetrating cavernosal arteries and timely emptying into deep dorsal veins. No arteriovenous fistula or vascular malformation. Recurrent Priapism

a b Figure 2: (a) Axial CT cavernosography shows right moderate and left mild corpus cavernosum fibrosis (red arrows). (b) coronal view shows dorsal non-opacification of the right corpus cavernosum (red arrowhead). The finding of fibrosis is likely from recurrent intermittent ischemia from priapism. The patient was diagnosed with stuttering (recurrent) priapism and counseled on preventive measures with phenylephrine intra-cavernosal injections to prevent further ischemic priapism. Priapism for more than 40 hours with fibrosis 30 yo took 1ml Cialis and had a normal erection and detumesced. 3 days later woke up at 4am with erection and after several hours became painful. Presented to a outside hospital 5 hours later. Managed with multiple phlebotomies and phenylephrine that were unsuccessful. Taken to the OR for a winter shunt placement and distal bilateral shunt placement. Never fully detumesced and transferred to our hospital. Figure 1: a b (a) Non- (b) Right non- opacification of opacification of the right proximal the corpus and mid corpus cavernosum cavernosum (red (red arrow) and arrows) and left left mild to mild to moderate moderate decrease decreased opacification (red opacification arrowhead ) (yellow arrowhead) Priapism for more than 40 hours with fibrosis

a b c

Figure 2: (a-c) 3D reconstruction shows non-opacification of the right corpus cavernosum and replacement with complete fibrosis (red arrows).

The patient will need a penile implant in the future due ischemic priapism. Peyronie’s Disease and Penile Deviation: pre-op evaluation

a b c d 70 yo presents with penile curvature noticed 6 months ago and erectile dysfunction.

Figure 1: (a) Physical exam with 90-degree dorsal curvature & multiple palpable plaques. US with trimix showed no vascular insufficiency (not shown). (b) Right severe and left moderate corporal fibrosis (red arrows). (c) Dorsal angulation of the penis. (d-e) Penile measurement of the right (d) and left (e) corpus cavernosum to determine the e size of the implant needed ( approx. 18cm) Peyronie’s Disease and Penile Deviation

a b c Figure 2: (a) Intra-operatively the left corpora measured 18.5cm and the right corpora measures 19cm. A 18cm 3-piece prosthesis was placed. Site of incision to release the tunica albuginea (green circle). (b) Incision at the side of the tunica albuginea where made to relax the penis (green arrow). (c) A graft (Tuto-plast) was placed to close the defect (between the green lines). Types of Penile Implant Device

1. Mallleable prosthesis (semi-rigid cylinders) 2. 2-piece prosthesis (2 cylinders with a scrotal pump, usually used for those contraindicated to have an abdominal reservoir placed) 3. 3-piece prosthesis (2 cylinders, a scrotal pump and an abdominal reservoir filled with saline).

Figure shows 3-piece Complications prosthesis. Figure obtained from ET 1. Infected implant Chonrey et al 2. Distal cylinder erosion 3. Pump migration 4. Reservoir displacement CT and MR Imaging Features of Artificial Urinary Sphincters, Penile Prostheses, and Other Devices in the Male Lower Genitourinary Tract | RadioGraphics [Internet]. [cited 2020 Feb 4]. Available from: https://pubs.rsna.org/doi/10.1148/rg.2018170087 Extrusion of Penile Implant pre-op Evaluation 58 yo who underwent penile implant 10 months ago. 1 month ago had difficulty inflating the device and felt it “went out of place”. Pre-op CT evaluation.

(a) Coronal reformat (b) Sagittal reformate again (c) 3D reconstruction demonstrates the extruded shows the extruded implant demonstrates the pump inflatable cylinder within the device and the pump (red (yellow arrow) and the scrotum (red arrows) and rear tip arrow) extruded rear tip extenders extenders abutting the corporal (red arrows) bodies (red arrowheads) Extrusion of Penile Implant: Intraoperative Removal

Figure 2: It was found that the right Figure 1: Intraoperative finding of a 22 cm prosthesis was placed periurethral instead of long penile implant outside the corporal intra-cavernosal (red line periurethral bodies was removed (red circle) space, blue line cavernosal lumen) Mechanical Failure of Implant Device 67 yo with penile implant placed 10 years ago. 1 year ago the penile implant did not inflate. Inability to inflate on physical exam. Underwent CT for pump failure.

3D reconstruction demonstrate Coronal reformate demonstrates Axial CT shows the reservoir in left cylinder rupture (yellow the left ruptured cylinder (red the space of retzius on the right circle) arrow) that is deflated and air filled (red arrow). Left cylinder rupture with a flat reservoir requiring removal and re-implantation. Conclusion • CT Cavernosography is a straightforward examination providing anatomic and functional information Ø Type and extent of venous leakage in men with erectile dysfunction Ø Extent and location of corporal fibrosis Ø Detailed anatomy for surgical planning (penile implants and reconstructive surgeries)

• It is an excellent educational tool for patients to help facilitate discussion on treatment options References

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