Question

An otherwise healthy $34$-year-old woman is brought to the emergency department due to the sudden onset of severe, right-sided pelvic pain that began abruptly while she was exercising $3$ hours ago. She reports two episodes of non-bilious emesis since the pain started. Her last menstrual period was $2$ weeks ago, and she has regular $28$-day cycles. She has no history of sexually transmitted infections or prior abdominal surgeries. Her temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $132/82\text{ mm Hg}$, pulse is $108/\text{min}$, and respiratory rate is $16/\text{min}$. Physical examination reveals a non-distended abdomen with marked tenderness to palpation in the right lower quadrant. Voluntary guarding is present, but there is no rebound tenderness. Pelvic examination demonstrates a tender fullness in the right adnexa. A urine pregnancy test is negative. Laboratory studies show a leukocyte count of $11,500/\mu\text{L}$. A transvaginal ultrasound with color Doppler is performed. The right ovary measures $6.5\text{ cm} \times 5.0\text{ cm} \times 4.5\text{ cm}$ and exhibits a heterogeneous stroma with multiple peripherally displaced follicles. Color Doppler evaluation demonstrates the presence of arterial blood flow, but venous flow is entirely absent. The left ovary is normal in size and appearance. A small volume of anechoic free fluid is noted in the rectouterine pouch (cul-de-sac). Based on the imaging findings, which of the following is the most appropriate next step in management?