Male Pelvic Vessels

Prepared and reviewed by the PrepElephant Academic Review Team

First published 2 Oct 2026 · Spot an error?

On this page

Direct answer
What you must remember
Operating within the pelvic vasculature
How examiners probe this region
Frequently asked questions
Related topics

Direct answer

Every artery of the male pelvis is a branch, direct or indirect, of the internal iliac, which arises from the common iliac over the sacroiliac joint and divides at the upper border of the greater sciatic foramen. The posterior division is parietal — iliolumbar, lateral sacral and superior gluteal; the anterior division mixes visceral branches (superior vesical, inferior vesical, middle rectal) with parietal ones (obturator, internal pudendal, inferior gluteal). Venous drainage mirrors this through the internal iliac vein, with the valveless prostatic venous plexus of Santorini receiving the deep dorsal vein of the penis and communicating freely with the vertebral venous plexus — the anatomical route behind prostate cancer's predilection for the spine.

What you must remember

Posterior division (three parietal branches): iliolumbar, lateral sacral and superior gluteal — the superior gluteal is the largest branch of the internal iliac and the only artery to leave the greater sciatic foramen above piriformis.
Anterior division order: the umbilical artery gives the superior vesical branches then becomes the medial umbilical ligament; obturator, inferior vesical, middle rectal, internal pudendal and inferior gluteal follow.
Internal pudendal course: out through the greater sciatic foramen below piriformis, around the sacrospinous ligament, and back in through the lesser sciatic foramen to Alcock's (pudendal) canal on the obturator internus fascia — the artery of erection, ending as the deep and dorsal arteries of the penis.
Prostatic venous plexus (Santorini): valveless network over the prostate and bladder neck receiving the deep dorsal vein of the penis; bleeding here is the classic hazard of prostate surgery.
Batson's vertebral venous plexus connection: valveless communication between prostatic and vertebral plexuses explains skeletal metastases of prostate carcinoma without pulmonary seeding — a viva staple.
Lymphatic map: prostate drains chiefly to internal iliac and obturator nodes (the sentinel node group in prostate cancer), bladder to external and internal iliac nodes, anal canal above the dentate line to internal iliac nodes.
Pelvic fracture haemorrhage: branches of the internal iliac, especially the superior gluteal near the greater sciatic notch, are the usual source of concealed pelvic bleeding.

Operating within the pelvic vasculature

Follow the surgeon's eye during a radical prostatectomy. The first structure of consequence is the deep dorsal venous complex emptying into Santorini's plexus anterior to the prostate; control of this plexus defines a bloodless field, because the veins are thin-walled, valveless and under pelvic venous pressure. Lateral to the prostate the neurovascular bundle runs with the prostatic arterial supply from the inferior vesical artery; sparing it preserves erectile function, dividing it widens the cancer margin — the operative trade-off made in millimetres. Posteriorly, the middle rectal artery crosses to reach the rectum, marking the plane between rectum and prostate that must be opened without breaching either.

The same map guides other specialties. The orthopaedic surgeon fixing an acetabular fracture knows the superior gluteal artery is tethered at the greater sciatic notch and tears with displaced posterior column fragments; the interventional radiologist embolising pelvic bleeding targets the internal iliac branches selectively, preserving at least one internal iliac system to avoid gluteal and pelvic organ ischaemia. In every case, survival of the operation is decided by whether the surgeon had drawn the vessel map before cutting.

How examiners probe this region

The standard viva ladder starts with naming the branches of the internal iliac artery, and the expected structure is the division-based grouping — posterior parietal three, anterior mixed visceral and parietal — rather than an alphabet of vessels. The second rung asks which artery leaves above piriformis (superior gluteal, alone) and which structures accompany the internal pudendal artery (pudendal nerve, then nerve to obturator internus nearby). The applied summit is oncological: why prostate carcinoma metastasises to the lower spine and why prostate surgery risks torrential venous bleeding — both answered by the valveless prostatic and vertebral plexuses. Candidates who mention that ligation of both internal iliac arteries is tolerated because of contralateral and systemic collaterals, yet may still cause gluteal claudication, close the topic with distinction.

Frequently asked questions

What are the branches of the posterior division of the internal iliac artery?

Iliolumbar, lateral sacral and superior gluteal arteries — all parietal, with the superior gluteal being the largest branch of the internal iliac.

How does the internal pudendal artery reach the perineum?

It leaves the greater sciatic foramen below piriformis, hooks around the sacrospinous ligament, re-enters through the lesser sciatic foramen and runs in Alcock's canal on the obturator internus fascia.

Why does prostate cancer spread to the vertebrae?

The valveless prostatic venous plexus communicates with the vertebral venous plexus, permitting retrograde seeding of the spine without passage through the lungs.

Which lymph nodes first receive prostate cancer?

Primarily the internal iliac and obturator nodes, which is why obturator node biopsy or extended pelvic lymph node dissection is used for staging.

What is the source of severe bleeding in pelvic fractures?

Tears of internal iliac branches, most commonly the superior gluteal artery at the greater sciatic notch, plus venous plexus bleeding.