Female pelvic congestion syndrome: how can CT and MRI help in the management decision?

Abstract

Objective:

Diagnosis of female pelvic congestion syndrome (PCS) is challenging. Although invasive venography is the gold-standard for diagnosis, however, CT and MRI are important in the assessment. In this study, we tried to highlight the role of CT and MRI as non-invasive tools in the diagnosis and management of PCS.

Methods and material:

This was a retrospective study of 50 patients confirmed clinically to have PCS. These patients had already done CT and MRI before venography or surgery.

Results:

The mean age of the patients was 48 years ± 12 years SD. Vaginal discharge and pelvic heaviness were the commonest symptoms (46 and 42% respectively). The commonest risk factor was multiparity (56%) followed by the RVF uterus (26%). No significant difference was found between CT, MRI, and venography as regarding the diameter of the ovarian vein, diameter, and the number of the varicose veins. The sensitivity of CT and MRI was 94.8 and 96%. CT and MRI discovered five cases with local pelvic obstructing cause,14 cases with evidence of vascular compression syndrome, and the rest 31 cases diagnosed to have primary non-obstructing PCS which was effective in decision-making with the surgery indicated in the first group while stenting of the vascular obstruction followed by bilateral ovarian veins coiling was the better option for the second group and only bilateral coiling was needed for the last group.

Conclusion:

CT and MRI play important roles in the diagnosis and even management decision in cases of PCS.

Advances in knowledge: :

Identification of the importance of diagnostic radiology before management decisions of cases with PCS.

Background

Chronic pelvic pain is diagnosed as a continuous disabling pelvic pain for 6 months not related to the menstrual cycle with no response to the usual medical treatment. Its causes are multiple and may be combined. Endometriosis comes on top of its causes and some considering that, endometriosis represents about 30% of the cases with chronic pelvic pain. ^1,2

Female pelvic congestion syndrome (PCS) considered one of the most important challenging causes of chronic pelvic pain in the female. Its diagnosis is multidisciplinary work depending on the co-operation between multiple specialties including obstetrician/gynecologist, radiology specialist, and other specialties that may be involved as urology, neurology, and psychiatrist. ³

PCS in the female is like varicocele in males yet being internal, non-visualized, and pelvic in position, its diagnosis is difficult. The symptoms of PCS are related to the presence of pelvic and ovarian varicosities. The patients usually complain of pelvic heaviness feeling or lower abdominal dull aching pain that increases at the end of the day and with exercises. Also, it may be associated with dysuria, dysmenorrhea, vaginal discharge, and dyspareunia. The pain increased after and before the menstruation and after sexual intercourse and during pregnancy period. This is may also be associated with lower limb varicosities. Some patients may complain of depression due to the prolonged duration needed for diagnosis. ^4,5

The exact pathology of chronic PCS still unclear, yet multiple risk factors were found to have a role in the development of incompetent pelvic and ovarian veins and valvular disorders which represent the non-obstructing form of PCS and some called it pelvic venous insufficiency (PVI) such as a family history of varicose veins, history of pelvic surgery, repeated pregnancies and hormonal changes with estrogen hormone suggested to cause venous wall weakness. ³

The pelvic varicosities are more seen on the left side due to the anatomical insertion of the left ovarian vein into the left renal vein in controversy to the direct drainage of the right ovarian vein into the IVC. Also, anatomical abnormalities play a role in the development of obstructive PCS such as the Nutcracker phenomenon. PCS may appear as a complication of other pelvic pathologies such as tumors causing secondary pelvic congestion with the development of varices. ⁶

TV ultrasound has a lot of limitations in the diagnosis of cases with PCS. It is an operator-dependent technique, time-consuming with painful maneuver with cases already having deep pelvic pain, inability to assess the vascular abnormalities cause of pelvic varices which is common, and lastly can’t be done for virgin females. ⁷

Radiological investigations like CT and MRI play a cornerstone role in diagnosis and even selection of an appropriate type of treatment for the cases with PCS. First, to exclude other causes of chronic pelvic pain. Secondary, the diagnosis of PCS. The treatment strategy decision is depending on the radiological findings, severity, and causes of PCS. ⁸

The transcatheter venography is the gold standard for diagnosis of PVI and pelvic varicosities yet being an invasive procedure, its use now limited to venous planning before embolization or when the diagnostic imaging as CT and MRI are non-conclusive. Percutaneous pelvic vein embolization is one of the important treatment options for cases with PCS. It is characterized by being less invasive compared to the surgery with a low incidence of morbidity and mortality using a variety of embolic agents as foams or coils. The embolization technique used when the cause is congenital or acquired incompetent pelvic veins while if there is venous obstruction or secondary to pelvic pathology, it must be treated first. ^6,9

In this study, we tried to highlight the role of CT and MRI as non-invasive tools in the diagnosis and assessment of cases with pelvic congestion syndrome. And, to evaluate to what extent the CT and MRI can alter the management strategy of the patients.

Methods

Patients

This was a retrospective study conducted on selected 50 patients diagnosed to have chronic pelvic congestion syndrome and came for pelvic vein embolization or surgery as a management for their condition. All selected patients have done either CT or MRI examination before the embolization process. The study was conducted over the period from January 2019 to March 2020. Approval of the institutional ethical committee was obtained to use the patient’s data with no need for consent being a retrospective study with complete precaution regarding the confidentiality of the patients' data. The clinical data and history were checked with special concern regarding the risk factors for the development of PCS.

Inclusion criteria

All patients with a diagnosis of PCS excluding the other causes of pelvic pain and they all had CT or MRI before any interventional procedure. No age predilection.

Exclusion criteria:

We excluded patients with chronic pelvic pain with another diagnosis other than PCS such as patients with pelvic pathology without the development of pelvic varicosities. Patients diagnosed as PCS with no available CT or MRI before the management. No available data about the management strategy.

Technique

• CT technique:

  • CT machine and technique: The study was performed using a 16-slice CT machine (High speed, GE “general electric”, USA) or an 80-slice CT machine (Prime Aquilion, Toshiba, USA). The patients were put in the supine position. Scout was taken starting from above the dome of the highest copula of the diaphragm down to the mid-thigh level. The scanning process was acquired using bolus tracking technique with the region of interest (ROI) placed at the abdominal aorta below the level of the renal arteries with intravenous injection of 100 ml non-ionic contrast medium (Omnipaque 350 or Ultravist 370) at a rate of 4–5 ml/s using an injection pump (Medrad injector) via a wide pore cannula better to be inserted in the anticubital vein. The arterial phase was taken followed by the venous phase 10 s later.
  • CT parameter, image interpretation, and the diagnostic CT criteria for PCS were summarized in (Table 1).

• MRI technique: it was adjusted for both anatomical and vascular evaluation. We used Philips superconductive magnet system 1.5 T using an abdominal coil.

  • MRI parameter, image interpretation, and the diagnostic MRI criteria for PCS were summarized in (Table 1).

• The 1ry management decision for cases with PCS usually was ovarian vein coiling. A multidisciplinary meeting was held to check the management decision taken for the selected patients depending on the CT and/or MRI results and to what extent these results changed the patient’s management plan.

• The conventional venography studies of the patients who underwent coiling or coiling and vascular stenting were revised and data about the presence of unilateral or bilateral varicosities, the diameter of the ovarian veins, number, and maximum diameter of the varicosities were collected to be compared with the CT and MRI results.

Table 1.

Show the image acquisition, image interpretation, and the diagnostic criteria for the CT and MRI used in the diagnosis of pelvic congestion syndrome.

	CT technique	MR technique
Image acquisition:	1.25 mm slice thickness.  0.625 mm slice interval.  512 × 512 matrix.  Tube speed 35 mm/rotation.  0.5 s rotation time.  The Kv was 120.  The mA ranging from 150 to 400 according to body weight.	Single-shot fast spin-echo (coronal).  T2 weighted Images (Axial, sagittal, coronal).  T2 weighted fast spin (axial).  Diffusion-weighted (axial).  Contrast-enhanced T1 weighted images (axial, coronal, sagittal).
Images interpretation:	The images were transferred to the workstation for image analysis which was performed by a radiologist experienced in female imaging with at least 3 years’ experience blinded to the aim of the study and the patient’s clinical status.  The following parameters were assessed:  Presence of pelvic varicosities (number and diameter).  The diameter of the ovarian vein.  Presence of pelvic pathology.  Presence of vascular anatomical abnormalities
Diagnostic criteria:	At least four ipsilateral parauterine veins of varying caliber.  At least one measuring more than 4 mm in diameter.  They appeared as tortuous dilated veins filled with contrast surrounding the uterus, vagina, ovaries, and along the sides of the pelvic wall.  An ovarian vein diameter was greater than 8 mm.  Absence of obstructing mass lesions. 10	At least four dilated parauterine varices with dilated ovarian vein >8 mm.  They appeared as multiple dilated tubular structures displaying flow void signal (hypointense) on T1WI and hyperintense signal on T2 or sometimes heterogeneous due to slow turbulent flow that was filled with contrast after contrast injection.  Absence of an obstructing mass or structural obstruction.  No evidence of endometriosis. 10,11‚ 12

Sample size calculation:

Using PASS II program for sample size calculation and according to a previous systematic review done by Steenbeek et al, ¹³ the expected sensitivity of CT or MRI for diagnosis of PCS is ranging from 80 to 100%, setting power at 80 and ά error at 0.05, a sample size of at least 20 patients were needed for each method.

Analysis of data:

The analysis of data was done using IBM SPSS statistics (v. 25.0, IBM Corp., USA, 2017–2018) was used for data analysis. Data were expressed as Mean ± SD for quantitative parametric measures in addition to both number and percentage for categorized data. χ² test to study the association between every two variables or comparison between two independent groups as regards the categorized data. The probability of error at 0.05 was considered sig., while at 0.01 and 0.001 are highly sig.

Results

This is a retrospective study conducted on 50 selected patients presented with a clinical diagnosis of PCS and underwent CT and MRI study before the management decision (Figure 1). 32 patients underwent CT and MRI before the management decision, 10 patients underwent CT only, and the rest 8 patients underwent MRI only.

Figure 1.

Flowchart of the selected patients during the different levels of the study. PCS, pelvic congestion syndrome.

The mean age of the selected patients was 48 years ± 12 years SD. The main symptom presented was vaginal discharge reported in 23 cases (46%) followed by pelvic heaviness sensation reported in 21 cases (42%). Regarding the risk factors for the development of PCS, multiparity was the commonest with 28 patients had a history of labor more than twice. This is followed by the RVF position of the uterus documented in 13 patients (Table 2).

Table 2.

Demographic data of the study population including the mean age, presenting symptoms, and the presence of risk factors for the development of PCS

	Number (%) (Total = 50)
Mean age ± SD	48 ± 12 years old.
Presenting symptoms:
- Discharge.	23 (46%)
- Heaviness.	21 (42%)
- Dysmenorrhea.	12 (24%)
- Dysuria.	11 (22%)
- Dyspareunia.	9 (18%)
Risk factors for PCS:
- Multiparity (>2).	28 (56%)
- RVF/AVF	13 (26%)
- Pelvic surgery.	11 (22%)
- PCO (polycystic ovary)	7 (14%)

PCO, polycystic ovary; PCS, pelvic congestion syndrome; SD, standard deviation.

After MRI and CT results, the decision was surgical treatment for five cases without the need for conventional venography. 45 patients out of 50 underwent conventional venography. The results of the CT and MRI were compared to the conventional angiography and we found no significant difference between the CT, MRI, and conventional venography as regards the diameter of the ovarian vein, number, and size of the varicose veins (Table 3).

Table 3.

Shows the mean, median, standard deviation of the ovarian vein diameter, diameter, and the number of the varicose veins as measured by CT and MR compared to the conventional angiography result

	The average diameter of the ovarian vein (mm)		p-value	The maximum diameter of the varicose vein (mm)		p-value	The number of varicose veins (no.)		p-value
	CT	Venography		CT	Venography		CT	Venography
Mean	8.46	8.41	0.894 (NS)	4.58	4.57	0.709 (NS)	6.08	6.13	0.909 (NS)
Median	8.5	8.5		4.6	4.55		6	6
SD	±0.58	±0.65		±0.393	±0.32		±1.61	±1.57
	MR	Venography	p-value	MR	Venography	p-value	MR	Venography	p-value
Mean	8.39	8.42	0.927 (NS)	4.63	4.64	0.744 (NS)	6.57	6.35	0.636 (NS)
Median	8.5	8.6		4.7	4.6		7	6
SD	0.64	±0.65		±0.35	±0.36		±1.32	±1.64

SD, standard deviation.

CT diagnosed three patients with unilateral varicosities although they had bilateral varicosities as confirmed by invasive venography. Similar to CT, MRI missed the diagnosis of bilateral varicosities in two cases (Table 4). The sensitivity of CT for the diagnosis of PCS was found to be 94.8% while in MRI was found to be 96%. 18 cases (36% of the total cases) were diagnosed to have left side-unilateral varicose veins as confirmed with conventional venography.

Table 4.

The number of patients diagnosed to have unilateral or bilateral pelvic varicosities by CT and MRI compared to the conventional venography

	Unilateral	Bilateral	Total number
CT	25	15	40
Conventional venography	22	18	40
MRI	25	12	37
Conventional venography	23	14	37

The 1ry decision which was taken for the management of the cases with PCS was the ovarian vein coiling. However, after the analysis of the results of the CT and MRI, the treatment was changed in 38% of cases (Table 5). 14 patients needed vascular stent application before ovarian coiling due to the diagnosis of vascular compression syndrome leading to obstructing PCS (Figures 2–5). Five patients underwent surgical treatment for a local pelvic pathology diagnosed by CT or MRI to be the cause of secondary PCS (Figure 6). The rest 62% of the cases were treated as 1ry decision with unilateral or bilateral ovarian coiling (Figures 7 and 8).

Table 5.

Showing the cause of PCS as described by the CT and MRI and the decision taken for management

CT/MRI findings	Number (%)	Management decision
- Local pelvic obstructing cause	5 (10%)	Surgical treatment.
- Vascular compression syndrome:  ✓Anterior Nutcracker syndrome (Figure 2).  ✓Posterior Nutcracker syndrome (Figure 3).  ✓May-Thurner syndrome (Figures 4 and 5).	6 (12%) 5 (10%) 3 (6%)	Stent application for the vascular obstruction followed by ovarian veins coiling.
- No definite cause	31 (62%)	Bilateral ovarian vein coiling
Total number	50 (100%)

PCS, pelvic congestion syndrome..

Figure 2.

A P3 female patient 36 years old complain of vaginal discharge and dysmenorrhea and diagnosed clinically as a case with PCS underwent MRI and CT before management decision which was expected to be bilateral ovarian coiling. (A, B) MRI axial image T ₂ WI and post-contrast T ₁WI reveals the presence of bilateral polycystic ovaries as well as a right ovarian cyst. This is associated with bilateral parauterine and pelvic varicosities appear as serpiginous signal void vessels in A and enhanced tortuous vessels in B (white arrow). (C, D) Axial CT image of the same patient reveals left renal vein compression between the aorta and SMA (anterior nutcracker syndrome) (red circle in C) associated with bilateral dilated ovarian veins (green circle in D). The decision of treatment changed to be stenting of the left renal vein and bilateral ovarian coiling. PCS, pelvic congestion syndrome.

Figure 3.

A P4 female patient 45 years old complain of heaviness sensation and vaginal discharge, diagnosed clinically as a case with PCS underwent CT before management decision. (A, B) Axial and sagittal post-contrast CT images reveal a retro-aortic course of the left renal vein with vascular compression syndrome known as posterior nutcracker syndrome (red circle in A, B) associated with left ovarian vein dilatation (green circle in C) as well as multiple left-sided pelvic and parauterine varices (white arrow in D). The decision of treatment changed to be stenting of the left renal vein and left ovarian vein coiling. PCS, pelvic congestion syndrome.

Figure 4.

A P2 female patient 45 years old complain of heaviness sensation, dysuria, and vaginal discharge, diagnosed clinically as a case with PCS underwent MRI before management decision. The axial T ₂WI image shows bilateral pelvic varicosities appear as serpiginous intermediate signal vessels (white arrow in A) which appear hyperintense in STIR (white arrow in B) and hypointense on T ₁W (white arrow in C). Post-contrast axial T ₁WI reveals bilateral pelvic enhancing tortuous varicose veins (white arrow in C, D). PCS, pelvic congestion syndrome; STIR, short-tau inversion recovery.

Figure 5.

The same patients in Figure 4 with post-contrast CT. (A, B) Axial CT images show vascular compression syndrome in the form of compression of the left common iliac vein by the right common iliac artery (May Thurner syndrome) (Red circle in A, C) associated with bilateral tortuous dilated parauterine and pelvic varicosities (white arrow in B). image D shows a 3D reformat image describing the associated left lower limb varicose veins. 3D, three-dimensional.

Figure 6.

A P1 female patient 52 years old complain of heaviness sensation and dyspareunia diagnosed clinically as a case with PCS underwent MRI before management decision. The axial and sagittal T ₂WI image shows right lateral subserosal fibroid as well as large anterior wall exophytic subserosal fibroid (F in images A, B). This is associated with multiple right pelvic and parauterine varicosities that appear as serpiginous signal void vessels (white arrow in C, D). PCS, pelvic congestion syndrome.

Figure 7.

A P3 female patients 45 years old complain of heaviness and dysmenorrhea. The patients underwent MRI and CT with the final diagnosis was non-obstructing PCS. (A–C) Axial T ₁WI showing bilateral pelvic varicosities as multiple para-ovarian and para-uterine tubular serpiginous signal void structures (white arrow). A dilated right and left ovarian veins were noted (white circle in A, C respectively. Post-contrast CT study as seen in image D shows bilateral dilated ovarian veins (white circle) with no definite vascular compression cause. The management decision was bilateral ovarian coiling. PCS, pelvic congestion syndrome.

Figure 8.

The same patient in Figure 7 who was diagnosed to have primary non-obstructing PCS and the treatment decision was bilateral ovarian coiling. (A, B) Images show the catheter inserted into the left ovarian vein with evidence of left side varicose veins with crossing veins to the right side and positive reflux into the right ovarian vein. Left side coiling was followed by catheterization of the right ovarian vein (image C). Image D shows a successive bilateral ovarian coiling. PCS, pelvic congestion syndrome.

Discussion

30% of the patients with chronic pelvic pain show no abnormalities during the routine diagnostic workup and finally found to have PCS diagnosed by specific pelvic imaging. ^9,14

PCS is a challenging disease in its diagnosis with multiple investigations must be done for proper management decision decreasing the rate of the patient’s morbidity and incidence of recurrence. Hence, in this retrospective study, we assessed the CT and MRI results of 50 patients diagnosed to have PCS and detected the role of the non-invasive imaging in the diagnosis of the cause and to what extent these results affect the management strategy of the patients.

Multiple presenting symptoms were detected in our study with vaginal discharge, and pelvic heaviness were the commonest presenting symptoms and this is consistent with Knuttinen et al as well as Ignacio et al articles discussing the multiple presentation symptoms and complains caused by PCS. ^3,8

Multiparity was the commonest risk factors found in our study population found in 28 cases representing 56% of our cases. This is also consistent with Kuligowska et al and Nicholson et al who documented that, PCS is typically presented in childbearing age and multiparous females. ^4,15

We found predominant left-sided pelvic and parauterine varicosities in 18 patients (36% of the cases) and this consistent with the anatomical consideration of left ovarian vein insertion into the left renal vein instead of direct insertion into the iliac vein. ⁶

CT and MRI are considered non-invasive radiological tools used during the management of cases with PCS. ⁹ The CT has the advantages of being less expensive, available, and considered the imaging modality of choice for diagnosis of vascular compression syndromes due to its highest temporal and spatial resolution with the advantages of post-imaging processing in the form of multiplanar reformatting as well as 3D reconstruction images. ¹⁶ No clear data were available about the sensitivity and diagnostic accuracy of CT in the diagnosis of PCS. ⁹ Our results revealed CT sensitivity equal to 94.8% with no statistically significant difference found between the CT and the conventional venography in the assessment of the ovarian vein diameter, number, and the diameter of the varicose veins. However, the CT missed the diagnosis of bilateral varicosities in three cases which were diagnosed by CT to have unilateral varicosities. Although CT has higher temporal and spatial resolution especially during imaging of the vascular structure, yet still of limited value for detection of the direction of flow and assessment of the reflux status of the veins.

Kauppila et al ¹⁷ found MR venography sensitivity and specificity were 88 and 67% for ovarian veins, 100 and 38% for internal iliac veins, and 91 and 42% for the pelvic plexus while Yang et al ¹³ found a time-resolved MRI sensitivity of 100% among 19 patients. Yang et al ¹⁸ found 67–75% sensitivity of time-resolved MR angiography for ovarian reflux with 100% specificity. This is comparable to our result showing MR sensitivity equal to 96%. We couldn’t calculate the specificity due to the absence of a control group.

Asciutto et al ¹⁹ studied the role of MR venography in the assessment of venous insufficiency in the pelvic plexus, ovarian vein, and hypogastric vein and resulted in a sensitivity of 91%, 88%, and 100%, respectively. Meneses et al ²⁰ used a phase-contrast velocity mapping and concluded a sensitivity of 100% and specificity of 50%, based upon nine patients with suspected PCS.

The main goal of this study was to highlight the effect of CT and MRI results on the decision plan of the patients. We found 14 cases (28 %) with vascular compression syndrome representing vascular obstruction cause of PCS which needed change in the management plan with the insertion of a stent at the site of vascular compression followed by ovarian vein coiling. These cases with vascular compression syndrome were best demonstrated by CT.

Six cases (12%) described having anterior nutcracker syndrome which also known as superior mesenteric artery syndrome with the left renal vein compressed between the aorta and SMA. Its diagnosis depends on the presence of a narrow aortomesenteric angle (AMA) (<15) and decreased aortomesenteric distance (AMD) (<8 mm). ^16,21 This is close to Scultetus et al ²² who described nutcracker syndrome with SMA compression in 17.9% of patients with PCS while in Holdstock et al ²³ study described the anterior nutcracker syndrome in only 2% of patients.

We described five cases (10%) with posterior nutcracker syndrome which occurred secondary to the retro-aortic course of the left renal vein with compression of the renal vein between the aorta and spine. It is recorded to be found in 3% of the population. ²⁴

May-Thurner was the least form of vascular compression syndrome detected in our study, only found in three cases (6%). It is defined as left external iliac vein compression against the right common iliac artery and is considered a rare cause of PCS and usually presented with thromboembolic manifestation. The diagnosis of such condition is essential before surgical or embolization treatment of cases with PCS as stenting of the left common iliac vein will be acquired. ²⁵

Although the surgical treatment is 100% curative, some reported 30% residual pain and 20% recurrence pain. So, it is now limited to the treatment of the PCS cases secondary to pelvic pathology commonly large fibroids. ^8,26 In our study, we found five cases (10%) diagnosed to have pelvic pathology as fibroids, and ovarian masses which were the actual cause of PCS and so, the surgical treatment was the decision taken for better care.

Limitation of the study:

It is a retrospective single institutional study. A multicentric study is needed for a larger sample size which of course will give us more accurate results. A control group was difficult to be available keeping in consideration the invasive nature of the venography technique which is the gold-standard and the reference investigation.

Conclusion

PCS management is a matter of challenge and needs multidisciplinary teams for accurate diagnosis, management, and better decision-taking aiming for adequate treatment with low morbidity and low incidence of recurrence. CT and MRI are non-invasive available diagnostic tools that must be done before management decision for diagnosis of vascular compression syndrome causing vascular obstructing PCS and diagnosis of pelvic pathologies which all change the management decision for better care.