Penile Arterial Revascularization





Revascularization can be done by several techniques, all of which have limitations. The operations that have been most successful connect the inferior epigastric artery to the dorsal artery (revascularization) or deep dorsal vein (arterialization).


In patients younger than age 45 years, make the diagnosis of reduced arterial inflow by the intracavernous injection and stimulation test and by duplex ultrasonography. Use color Doppler imaging to detect communications between the dorsal and cavernous arteries and the direction of blood flow. Locate the site of the block by phalloarteriography combined with intracavernosal papaverine injection. This serves three purposes: (1) to locate the site of blockage, (2) to confirm the presence of communications between the dorsal and cavernous arteries, and (3) to ensure that both the donor (the inferior epigastric) and recipient (dorsal) arteries are healthy. It is important to assess the inferior epigastric arteries on angiogram and assess which has the larger caliber with fewest branches because this will likely be the best one for harvest.


Instruments and Positioning


Provide the following: basic, genitourinary (GU) plastic, and GU micro sets; an Andrews suction tip; a bipolar hand electrode; a microscope and drape; a bulb syringe; Weck spears; microwipes; visibility background; vascular loops; vessel clips; vascular sutures; heparinized saline in a syringe with a 20-gauge angiocatheter sheath; 9-0 Dermalon sutures with an LE-100 needle; and 10-0 Dermalon sutures with a TE-100 needle. Place the patient in a supine position and place a Foley catheter.




Securing the Epigastric Artery


Make a vertical lower abdominal incision 2 fingerbreadths from the midline. Alternatively, make an oblique incision in Langer lines. Incise the anterior rectus sheath over the center of the muscle, open the sheath with scissors, and retract it laterally with Kocher clamps. Alternatively, a midline abdominal incision will allow access to both arteries in case the first is not suitable for the surgery.


Expose and dissect the inferior epigastric artery, including its two accompanying veins, from the connective tissue underlying the muscle and hold it in a vascular tape ( Fig. 125.1, A ). Continue dissecting cephalad to the level of the umbilicus to free the artery. Divide and ligate other, more proximal vascular branches. Apply papaverine hydrochloride topically to reduce arterial spasm.




FIGURE 125.1


( A , B ) Dissection of the inferior epigastric artery.


Another option is to harvest the epigastric artery laparoscopically. A balloon-tipped Hassan cannula is placed in the midline just below the umbilicus using a 1-cm transverse incision in the anterior rectus sheath. The balloon is inflated and the initial dissection is carried out bluntly. Two additional radially dilating (step) trocars are placed laterally in a triangular fashion ( Fig. 125.1, B ). The inferior epigastric bundle is identified below the arcuate line and bluntly dissected off the abdominal wall with sparing use of electrocautery. Placement of a vessel loop facilitates dissection in a cephalad direction. Branches of the vessel bundle are gently dissected free, clipped, and divided. The dissection of the vessel bundle is carried cephalad near the umbilicus and caudally to its origin from the external iliac artery. The vessel bundle is clipped and divided with the harmonic scalpel at the most cephalad extent of the dissection. A 10-mm port is placed ipsilaterally through the Hesselbach triangle via a small skin incision near the base of the penis. The artery is gently delivered through the port up to the base of the penis. A bulldog clamp is placed on the end of the artery for microvascular anastomosis.




Exposure of the Penile Vasculature


Make a short midline incision at the base of the penis, beginning at the pubic tubercle to the Buck fascia at the depth of the neurovascular bundle ( Fig. 125.2 ). Expose the base of the penis. Although some surgeons pass the epigastric artery through the inferior end of the rectus sheath, the authors generally pass it through the ipsilateral inguinal ring to avoid the possibility of kinking at the fascial level. Watch out for twisting and tension. Apply a microvascular clamp to the free end and remove the one placed at the proximal end after placing a vessel loop to allow reapplication if needed later. If a laparoscopic approach is used, the epigastric artery is brought to the external inguinal ring via the 10-mm port.




FIGURE 125.2


Incision for exposure of the penile vasculature.


The fundiform and suspensory ligament of the penis may or may not be taken down, depending on surgeon preference and the anastomotic site, although the penis should be resuspended to the pubic periosteum if the ligament is divided. Adventitia is removed only at the sites of anastomosis of the two vessels. The anastomosis is accomplished microscopically using 8-0 to 10-0 monofilament vascular suture. The vessels are clamped with low-tension vascular bulldog clamps, and the inferior epigastric artery is usually flushed with a dilute heparin or papaverine solution (or both) just before the anastomosis.


The surgeon has several choices for utilization of the epigastric artery, depending on the findings of arterial occlusion. The best solution usually is to connect the epigastric artery to the divided dorsal artery with an anastomosis of a branch both distally and proximally. The alternative is to anastomose the end of the epigastric artery to the side of the dorsal artery or to a segment of the deep dorsal vein, with or without an additional anastomosis to the dorsal artery. In the authors’ opinion, an adequate pressure gradient between the epigastric and dorsal arteries is critical to the success of the anastomosis. Therefore, before performing the anastomosis, assess the pressure gradient to help decide whether revascularization or arterialization is indicated. Request the anesthesiologist to set up an arterial line. Puncture the dorsal artery with a 25-gauge angiocatheter to measure the arterial pressure and insert the plastic sheath of the angiocatheter directly into the lumen of the transected epigastric artery. A pressure gradient of more than 15 mm Hg should exist to allow adequate flow through the anastomosis. If the gradient is less than 10 mm Hg, anastomosis to the dorsal vein is performed instead.


In the postoperative period, start mini heparin (5000 units subcutaneously every 12 hours for 2 days) after the anastomosis is completed followed by daily baby aspirin or dipyridamole (Persantine) for 3 months.


Epigastric Artery-Dorsal Artery Anastomosis


Arterial anatomy: The internal pudendal artery, becoming the penile artery, passes through the urogenital diaphragm and along the medial margin of the inferior ramus of the pubis. As it passes the bulb, it divides into three terminal branches—the bulbourethral, the dorsal, and the cavernous arteries. The bulbourethral artery enters the bulb of the urethra. The dorsal artery of the penis runs along the dorsum of the penis between the deep dorsal vein lying medially and the dorsal nerve lying laterally to it. It divides into a number of circumflex branches that supply the corpus. The cavernous artery enters the corpus cavernosum at the base of the penis and runs to the tip, giving off the multiple helicine arteries in the cavernous spaces. Crural arteries, small branches of the main penile artery, supply the crura on both sides ( Fig. 125.3 ).


Jan 2, 2020 | Posted by in UROLOGY | Comments Off on Penile Arterial Revascularization
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