Internal pudendal artery

The penis is mainly supplied by the internal pudendal artery, and three major sets of veins, superficial, intermediate, and deep veins, drain it. Drug-induced changes in neurotransmitter action can affect local blood flow. Vascular supply, intrinsic smooth muscles of the penis, and adjacent striated muscles are controlled by nerves arising from the thoracolumbar sympathetic, the lumbosacral parasympathetic, and the lumbosacral somatic systems. The pudendal nerve is the major somatic pathway innervating the male genitalia. 

Kawakami M, Minagawa T, Inoue H, et al. (2003) Successful treatment of arterial priapism with radiologic selective transcatheter embolization of the internal pudendal artery. Urology 61 645... 

Another case features a transient necrotic-appearing area on the right labium minus 5 days post UAE in a 38-year-old woman [110]. This was thought to be due to non-target labial embolization during UAE, perhaps of the internal pudendal artery. Spontaneous resolution occurred during the ensuing 4 weeks. 

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... 

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 fibrosis...

Anatomic Considerations The internal pudendal artery, a terminal branch of the anterior division of the internal iliac artery supplies the external genitalia. With extension to inguinal and iliac lymph nodes, additional supply originates from the obturator branch of the internal iliac artery, the inferior epigastric artery from the external iliac artery and the superficial epigastric artery and the superficial and deep external pudendal branches of the common femoral arteries. 

The main source of blood supply to the penis (Fig. 2.2a) is usually through the internal pudendal artery, a branch of the internal iliac artery. In many instances, however, accessory arteries arise from the external iliac, obturator, vesical, and/or femoral arteries, and may occasionally become the dominant or only arterial supply to the corpus cavernosum (Breza et al. 1989). Damage to these accessory arteries during radical prostatectomy or cystectomy may result in vasculogenic erectile dysfunction (ED) after surgery (Aboseif et al. 1994 Kim et al. 1994). 

The internal pudendal artery becomes the common penile artery after giving off a branch to the perineum. The three branches of the penile artery are the dorsal, bulbourethral, and cavernous arteries. The cavernous artery is responsible for tumescence... 

Much more complex is the dinical evaluation of patients who show PSV values between 25 and 35 cm/s. This range of values is commonly observed in older subjects with mild erectile dysfunction (Fig. 6.14). Probably they have a stiffness of the arterial walls with intimal thickening and reduced response to PGEl stimulation, secondary to an endothelial lesion and reduced NO production. In these patients stenosis or obstruction of the precavernosal arteries can be suspected and the flow study of these larger vessels should be performed. The terminal branches of the internal pudendal artery can be explored with a high linear frequency probe positioned in the perineal area under the scrotum. 

Direct identification of the arterial-lacunar fistula is obtained with Doppler techniques. Color Doppler ultrasonography allows identification of the lesion in virtually all patients only one case has been reported in which the fistula was not detected both at color Doppler and at angiography, but became evident only after empiric selective embolization of the contralateral internal pudendal artery (Ankem et al. 2001). 

Postraumatic penile arterial obstruction characteristically involves the proximal portion of the dorsal penile and cavernosal arteries and the distal internal pudendal artery at the level of the urogenital diaphragm. The integrity of arterial vascular supply to the penis can be assessed by Doppler interrogation of the cavernosal arteries. A peak systolic velocity of 25 cm/s or less after prostaglandin El intracavernosal injection reflects arterial insufficiency (Fig. 12.11). 

The human vagina, a fibromuscular tube 10-15 cm long, extends upwards and backwards from the vulva to the lower uterine cervix. Blood is supplied to the vagina via the uterine and pudendal arteries, and is drained from the vagina by a rich plexus, which flows into the internal iliac veins. The surface of the vaginal epithelium is kept moist by cervical secretions. The pH of vaginal fluid is 4-5. 

Figure 9.52 shows the blood supply to the rectal area. The main artery to the rectum is the superior rectal (haemorrhoidal) artery. Veins of the inferior part of the submucous plexus become the rectal veins, which drain to the internal pudendal veins. Dmg absorption takes place through this venous network. Superior haemorrhoidal veins connect with the portal vein and thus transport dmgs absorbed in the upper part of the rectal cavity... 

Technical Considerations The placement of the catheters in both internal iliac arteries, selectively into the main trunks, the anterior divisions, the vaginal arteries from the pudendals or the uterine arteries depends on the blood supply to the tumors and the flow distribution as evaluated by angiography, radionuclide flow study, and CT angiography. 

For example, in a patient with a hypervascular carcinoma of the uterine cervix as defined by angiography through catheters placed in the main trunk of the internal iliac arteries, the radionuclide flow study can be utilized to demonstrate the flow distribution almost exclusively to the true pelvis. Therefore, the position of the catheters would be adequate and more selective catheterization would not be necessary. On the other hand, in a patient with a hypovascular tumor (most squamous cell carcinomas of the cervix are relatively hypovascular), catheter placement into the internal iliac artery may not only infuse the true pelvis, but may also infuse the buttocks. Embolization of the superior and inferior gluteal arteries with coils or segments of Gelfoam or both can be used to prevent the infusion of the buttocks and redistribute the chemotherapy to the true pelvis. This may result in increased pudendal flow and potentially increase local toxicity. 

LA. Infusion Our experience with percutaneous intraarterial transcatheter chemotherapy in patients with recurrent carcinoma of the vulva and penis is limited. Therapy is usually delivered through the internal pudendal branch of the internal iliac artery, the external pudendal branch of the external iliac artery, and the external pudendal branch of the deep femoral artery. The chemotherapy regimen consisted of mitomycin C (10 mg/m over 24 h), bleomycin (20-40 mg/m over 24 h), and dsplatin (100 mg/m over 2 h). Although the number of patients treated under this regimen is too small for analysis, dramatic responses have been observed in several patients. 

Fig. 12.11a-c. Postraumatic erectile dysfunction. A 32-year-old patient who received pelvic bone fractures during a traffic accident, a Doppler interrogation of the cavernosal arteries shows low velocity flows of 12 cm/s, consistent with postraumatic arterial insufficiency, b Left internal pudendal arteriogram shows interruption of the vascular supply to the penis with no opacification of the cavernosal artery, c MDCT angiography demonstrates the same vascular features non-invasively... 

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