Pelvic congestion syndrome: a simple procedure but a complex condition and a challenging diagnosis Morteza Afrasiabi, Neda Noroozian, Kyriacos Patatas Radiology Department, Northwick Park Hospital Introduction: There is a 15% prevalence of chronic pelvic pain in premenopausal women, and the cause remains undiagnosed in up to 60%. Pelvic congestion syndrome can be responsible for chronic pelvic pain when pelvic venous insufficiency results in painful pelvic varicosities. However, patients with pelvic congestion syndrome can also present with haemorrhoids, vulvoperineal or posterior upper thigh varices, or previous varicose vein 3a 3b 4a 4b treatment failure. Endovascular treatment with pelvic and ovarian vein embolisation has been shown to be effective in providing significant symptomatic relief and has been gaining increased acceptance. There are challenges that can lead to difficulty in diagnosing the condition or treatment failure / partial response, especially the relatively low sensitivity of different imaging modalities, variant anatomy and associated anatomic disorders. Aims: 1. To demonstrate the anatomy of the interconnecting plexus of veins draining the pelvic organs and lower limb 2. To discuss the sensitivity of the different imaging modalities and objective findings on imaging for diagnosis 3. To demonstrate other anatomical disorders that can lead to failed result or partial response that progresses to failure Anatomy Figures 3a & 3b: Figures 4a & 4b: 3a: Refluxing right obturator vein Duplicated left ovarian vein before and after embolisation A detailed understanding of the relevant pelvic venous anatomy including common variants is essential for successful endovascular treatment. 3b: Embolised obturator vein Usually, blood in the left ovarian vein drains into the inferior vena cava (IVC) via the left renal vein (figure 1), whilst the right ovarian vein is Imaging: typically a direct tributary into the IVC variably between T12 and L2-3. There are anatomic variations for both the left and right ovarian vein, for Magnetic resonance imaging (MRI), transabdominal ultrasound (US) and computed example the left ovarian can occasionally be a direct tributary from the IVC or the right ovarian arise from the right renal vein. tomography (CT) can be used to exclude intrinsic pelvic pathology, but all of these studies The internal iliac venous plexus has a far more variable appearance. The veins most commonly responsible for symptomatic reflux are the are limited in their sensitivity for pelvic varices, in part because of the supine positioning, tributaries of the anterior division of the internal iliac artery – incompetent internal pudendal and broad ligament parametrial branches are and perhaps hydration and hormonal variation. The sensitivity for diagnosis of pelvic associated with pelvic venous congestion, whilst incompetent branches of the obturator and circumflex femoral veins are often associated with congestion syndrome is low – not exceeding 60% with MRI currently considered the most pelvic venous reflux into vulval or lower limb varicosities (figures 2 and 3). Incompetent ovarian veins may contribute to either clinical sensitive examination. manifestation. In experienced hands, transabdominal combined with transvaginal ultrasound has been It is important to be aware of variant anatomy. For example, the ovarian veins may be duplicated (figure 4), and the obturator vein which normally found to be useful in demonstrating both pelvic varices and pathological venous reflux. has two draining tributaries into the anterior division of the internal iliac vein may have two single draining veins into both the internal and external Sonographic findings include enlarged ovarian veins greater than 6 mm in diameter with iliac vein s (figure 5). Failure to appreciate the former will lead to treatment failure, failure to appreciate the latter can lead to disastrous reversed blood flow, presence of pelvic varicocele (> 5 mm) and dilated (> 5 mm) arcuate consequence of non-target embolisation. veins crossing the uterine myometrium between pelvic varicoceles. Despite negative findings on any of the above studies, venography (gold standard as widely available and objectively comparable) is indicated when clinical suspicion for pelvic Figures 1 a & 1b: 5 congestion exists. It can be performed for confirmation of the condition, and treatment can be performed at the same sitting. 1a: Left renal venography shows free reflux to the significantly Figure 5: dilated left ovarian vein. No patent venous valve is seen. Note Obturator vein draining into both internal (catheter in 1a 1b the extensive venous tributaries off the middle to distal portion of situ) and external iliac vein (arrow) the ovarian vein (arrow) 1b: Left ovarian venography shows stagnation of contrast Associated anatomical disorders (figures 6 and 7)that may be responsible for the dilated pelvic veins and will lead to failure of material in the dilated pelvic varices. Contrast refluxes across embolisation if unrecognised or left untreated (commonly require stenting prior to embolisation of pelvic veins) the midline to the contralateral ovarian and internal iliac veins (arrows) Figure 7 6 Figure 6 7 May-Thurner syndrome – Nutcracker compression of the left phenomenon – left common renal vein Iliac vein against the compression by lumbar spine by the overarching superior overlying right common mesenteric artery iliac artery. Figures 2a & 2b: Conclusion: 2a: Refluxing internal iliac venous branches with vulval In the appropriately selected/diagnosed patients, embolisation for pelvic congestion syndrome can achieve significant varicosities symptomatic improvement provided that meticulous attention has been paid to anatomy to identify variation or associated 2b: Refluxing internal iliac venous branches with lower anatomic disorders. limb varicosities References: 1. Pelvic congestion syndrome; patient information. British Society of Interventional Radiology 2a 2b 2. Kim HS et al. Embolotherapy for pelvic congestion syndrome: long term results. J Vasc Interv Radiol 2006; 17: 289-297 3. Lopez A. Female pelvic vein embolisation: indications, techniques, and outcomes. CVIR 2015; 38: 806-820 4. Durham JD, Machan LM. Pelvic congestion syndrome. Semin Intervent Radiol 2013; 30: 372-380 Contacts: Dr. Morteza Afrasiabi MD,MSc [email protected] Dr.Neda Noroozian MD,MRCP [email protected] .