What does an ovary with arterial flow demonstrating high resistant flow and absent diastolic flow indicate?

Ovarian Arterial Flow with High Resistance and Absent Diastolic Flow: Diagnostic Implications

An ovary with arterial flow demonstrating high resistance and absent diastolic flow strongly suggests ovarian torsion and requires urgent surgical intervention to prevent ovarian necrosis.

Doppler Findings in Ovarian Torsion

Doppler ultrasound findings in ovarian torsion follow a characteristic progression:

1. Early changes (partial torsion):

   • Diminished arterial velocity
   • Decreased diastolic flow
   • Increased resistive index
   • Venous outflow obstruction (occurs first) 1

2. Progressive changes:

   • Absent diastolic flow (your patient's finding)
   • Reversed diastolic flow 1

3. Complete torsion (>450° rotation):

   • Complete absence of both arterial and venous flow 1, 2

Diagnostic Classification Based on Doppler Findings

Based on the Doppler flow analysis, we can classify the severity of adnexal torsion:

• Class 1: Coiling with both arterial and venous ovarian blood flow
• Class 2: Coiling with arterial ovarian flow but no venous flow (your patient's presentation)
• Class 3: True strangulation with no ovarian blood flow 2

Clinical Significance

The high-resistance arterial flow with absent diastolic flow indicates:

1. Ongoing torsion process - The ovary is likely in the process of torsion with venous outflow obstruction that precedes complete arterial occlusion 1, 3

2. Urgent intervention required - Class 2 torsion (arterial flow present but venous flow absent) requires surgical intervention to prevent progression to complete ischemia 2

3. Potential for salvage - The presence of any arterial flow suggests the ovary may still be viable if promptly detorsed 1, 2

Important Caveats

• Normal Doppler does not exclude torsion - Studies show that 61% of right ovarian torsion cases and 27% of left ovarian torsion cases had normal Doppler flow 4

• Abnormal venous flow is highly sensitive - Absent or abnormal venous flow pattern has 100% sensitivity for torsion, even when arterial flow is present 3

• Early detection is critical - In some cases, abnormal ovarian venous flow may be the only abnormal ultrasound sign during early stages of adnexal torsion 3

Management Approach

1. Urgent gynecologic consultation for surgical evaluation

2. Surgical intervention (typically laparoscopic approach) with:

   • Detorsion as primary goal if tissue appears viable
   • Oophorectomy if necrosis is evident 5, 6

3. Additional imaging considerations:

   • If ultrasound is inconclusive, CT with IV contrast may be considered (sensitivity 74-95%, specificity 80-90%) 1, 5
   • Look for associated findings: enlarged ovary, edematous stroma, peripheral follicles, and twisted vascular pedicle 5

Conclusion

The finding of high-resistance arterial flow with absent diastolic flow in an ovary is highly concerning for ovarian torsion in the intermediate stage, where venous outflow is obstructed but arterial inflow is still partially preserved. This represents a surgical emergency requiring prompt intervention to preserve ovarian function.