Pelvis/Perineum

Pelvis/Perineum US Medical PG Question 1: A 33-year-old woman comes to the emergency department because of a 1-hour history of severe pelvic pain and nausea. She was diagnosed with a follicular cyst in the left ovary 3 months ago. The cyst was found incidentally during a fertility evaluation. A pelvic ultrasound with Doppler flow shows an enlarged, edematous left ovary with no blood flow. Laparoscopic evaluation shows necrosis of the left ovary, and a left oophorectomy is performed. During the procedure, blunt dissection of the left infundibulopelvic ligament is performed. Which of the following structures is most at risk of injury during this step of the surgery?

• A. Bladder trigone
• B. Uterine artery
• C. Kidney
• D. Ureter (Correct Answer)

Pelvis/Perineum Explanation: ***Ureter*** - The **infundibulopelvic ligament** (also known as the suspensory ligament of the ovary) contains the **ovarian artery and vein** and is in close proximity to the ureter as it crosses the pelvic brim. - During dissection or clamping of this ligament, especially in an emergency setting or when anatomy is distorted (e.g., by an enlarged ovary or edema), the **ureter** is highly susceptible to injury. *Bladder trigone* - The **bladder trigone** is the smooth triangular region at the base of the bladder, formed by the openings of the ureters and the internal urethral orifice. - It is not directly adjacent to the infundibulopelvic ligament and is therefore at a comparably lower risk of injury during dissection of this ligament. *Uterine artery* - The **uterine artery** travels within the cardinal ligament and supplies the uterus; it is located more medially and inferiorly within the broad ligament. - While important in pelvic surgery, it is not in the immediate vicinity of the infundibulopelvic ligament dissection itself. *Kidney* - The **kidneys** are retroperitoneal organs located much higher in the abdominal cavity, far superior to the pelvis. - They are not at risk of direct injury during pelvic surgery involving the infundibulopelvic ligament.

Pelvis/Perineum US Medical PG Question 2: A 36-year-old woman comes to the physician for a 2-month history of urinary incontinence and a vaginal mass. She has a history of five full-term normal vaginal deliveries. She gave birth to a healthy newborn 2-months ago. Since then she has felt a sensation of vaginal fullness and a firm mass in the lower vagina. She has loss of urine when she coughs, sneezes, or exercises. Pelvic examination shows an irreducible pink globular mass protruding out of the vagina. A loss of integrity of which of the following ligaments is most likely involved in this patient's condition?

• A. Infundibulopelvic ligament
• B. Broad ligament of the uterus
• C. Cardinal ligament of the uterus (Correct Answer)
• D. Round ligament of uterus
• E. Uterosacral ligament

Pelvis/Perineum Explanation: ***Cardinal ligament of the uterus*** - The patient's symptoms, including **vaginal mass**, **urinary incontinence** with coughing/sneezing, and history of **multiple vaginal deliveries**, strongly suggest **uterine prolapse**. - The cardinal ligaments are crucial in providing **lateral cervical support** and are often damaged during childbirth, leading to uterine descent. *Infundibulopelvic ligament* - This ligament primarily supports the **ovaries** and contains the **ovarian artery** and vein. - Damage to this ligament is associated with ovarian prolapse or complications during oophorectomy, not uterine prolapse. *Broad ligament of the uterus* - The broad ligament is a **peritoneal fold** that drapes over the uterus, fallopian tubes, and ovaries. - While it helps to hold these structures in place, its primary role is not in preventing uterine prolapse; it mainly provides a medium for neurovascular structures. *Round ligament of uterus* - The round ligament extends from the uterus to the **labia majora** and primarily helps maintain **anteversion** of the uterus. - It plays a minor role in uterine support and its laxity is not a primary cause of uterine prolapse. *Uterosacral ligament* - The uterosacral ligaments provide **posterior support** to the uterus, particularly by anchoring the cervix to the sacrum. - While damage to these ligaments contributes to **apical prolapse**, the cardinal ligaments are more critical for lateral support and more commonly implicated in overall uterine prolapse following childbirth.

Pelvis/Perineum US Medical PG Question 3: A 25-year-old homeless woman presents to an urgent care clinic complaining of vaginal bleeding. She also has vague lower right abdominal pain which started a few hours ago and is increasing in intensity. The medical history is significant for chronic hepatitis C infection, and she claims to take a pill for it 'every now and then.' The temperature is 36.0°C (98.6°F), the blood pressure is 110/70 mmHg, and the pulse is 80/min. The abdominal examination is positive for localized right adnexal tenderness; no rebound tenderness or guarding is noted. A transvaginal ultrasound confirms a 2.0 cm gestational sac in the right fallopian tube. What is the next appropriate step in the management of this patient?

• A. Tubal ligation
• B. Methotrexate
• C. IV fluids, then surgery (Correct Answer)
• D. Surgery
• E. Pelvic CT without contrast

Pelvis/Perineum Explanation: ***IV fluids, then surgery*** - This patient presents with an **ectopic pregnancy** confirmed by transvaginal ultrasound, along with signs of evolving instability (increasing pain, vaginal bleeding). She is also **hemodynamically stable** at present, so **resuscitation** with intravenous fluids is indicated before surgical intervention to prevent further deterioration. - While she is hemodynamically stable, the symptoms suggest the ectopic pregnancy is **progressing or rupturing**, necessitating a definitive surgical treatment to remove the gestastional sac and prevent hemorrhage. *Tubal ligation* - **Tubal ligation** is a permanent sterilization procedure and is not indicated for the management of an acute ectopic pregnancy. - While the ectopic pregnancy is in the fallopian tube, the immediate goal is to remove the ectopic pregnancy, not to sterilize the patient. *Methotrexate* - **Methotrexate** is an option for **medically stable** patients with **small, unruptured ectopic pregnancies**, without signs of hemodynamic instability or significant pain, and who can adhere to follow-up. - This patient has increasing pain, suggesting impending rupture or active bleeding, making methotrexate less appropriate. Her history of chronic hepatitis C and potential non-adherence to medication also makes methotrexate, a hepatotoxic drug, risky. *Surgery* - **Surgery** is the definitive treatment for an ectopic pregnancy. However, in any patient presenting with pain and vaginal bleeding, even if hemodynamically stable, initial **resuscitation with IV fluids** is crucial before proceeding with surgery to ensure optimal patient outcomes and prevent hypovolemia. - Directly proceeding to surgery without initial stabilization carries a higher risk, especially given the potential for significant blood loss during surgical removal of an ectopic pregnancy. *Pelvic CT without contrast* - A **pelvic CT without contrast** is not indicated as the initial management step for a confirmed ectopic pregnancy. - The diagnosis is already confirmed by transvaginal ultrasound, and a CT scan would expose the patient to unnecessary radiation without adding critical information for acute management.

Pelvis/Perineum US Medical PG Question 4: A 19-year-old woman presents to her gynecologist for evaluation of amenorrhea and occasional dull right-sided lower abdominal pain that radiates to the rectum. She had menarche at 11 years of age and had regular 28-day cycles by 13 years of age. She developed menstrual cycle irregularity approximately 2 years ago and has not had a menses for 6 months. She is not sexually active. She does not take any medications. Her weight is 94 kg (207.2 lb) and her height is 166 cm (5.4 ft). Her vital signs are within normal limits. The physical examination shows a normal hair growth pattern. No hair loss or acne are noted. There is black discoloration of the skin in the axillae and posterior neck. Palpation of the abdomen reveals slight tenderness in the right lower quadrant, but no masses are appreciated. The gynecologic examination reveals no abnormalities. The hymen is intact. The rectal examination reveals a non-tender, mobile, right-sided adnexal mass. Which of the following management plans would be best for this patient?

• A. Pelvic MRI should be the first-line imaging since both transvaginal and transabdominal ultrasound are inappropriate for this virginal, obese patient
• B. Clinical examination is sufficient for diagnosis since the adnexal mass was clearly palpable on rectal examination, making imaging unnecessary
• C. Transabdominal ultrasound is the appropriate first-line imaging for this virginal patient, despite reduced sensitivity due to her obesity, as transvaginal ultrasound would be inappropriate given her intact hymen
• D. The patient's obesity will not significantly affect transabdominal ultrasound quality, so transvaginal ultrasound is unnecessary even though she is virginal
• E. Transvaginal ultrasound should be performed first as it provides superior resolution for adnexal masses, regardless of the patient's sexual history or hymenal status (Correct Answer)

Pelvis/Perineum Explanation: ***Transvaginal ultrasound should be performed first as it provides superior resolution for adnexal masses, regardless of the patient's sexual history or hymenal status*** - **Transvaginal ultrasound (TVUS)** offers superior resolution for evaluating adnexal masses compared to transabdominal ultrasound due to its proximity to pelvic organs. - While patient comfort and sexual history are important, an intact hymen is **not an absolute contraindication** to TVUS; it can often be performed carefully with a smaller probe or with patient cooperation. *Pelvic MRI should be the first-line imaging since both transvaginal and transabdominal ultrasound are inappropriate for this virginal, obese patient* - **Pelvic MRI** is a valuable diagnostic tool but is typically reserved as a **second-line imaging modality** when ultrasound findings are inconclusive or more detailed tissue characterization is needed. - While obesity can reduce the quality of transabdominal ultrasound, and the patient is virginal, TVUS remains the **preferred initial imaging** due to its accessibility and high resolution. *Transabdominal ultrasound is the appropriate first-line imaging for this virginal patient, despite reduced sensitivity due to her obesity, as transvaginal ultrasound would be inappropriate given her intact hymen* - **Transabdominal ultrasound (TAUS)** would be challenging due to the patient's **obesity**, significantly limiting its sensitivity and resolution for adnexal structures. - While TVUS may seem challenging with an intact hymen, it is **not strictly contraindicated** and offers far better diagnostic yield than a suboptimal TAUS in this scenario. *Clinical examination is sufficient for diagnosis since the adnexal mass was clearly palpable on rectal examination, making imaging unnecessary* - A palpable **adnexal mass** on clinical examination, while an important finding, is **not sufficient for diagnosis** without imaging. - Imaging is essential to characterize the mass (e.g., solid, cystic, complex), size, location, and relationship to surrounding structures to guide appropriate management. *The patient's obesity will not significantly affect transabdominal ultrasound quality, so transvaginal ultrasound is unnecessary even though she is virginal* - **Obesity significantly impairs** the quality and penetration of transabdominal ultrasound, making it difficult to visualize pelvic organs and adnexal masses clearly. - Therefore, transabdominal ultrasound is unlikely to provide sufficient diagnostic information in this obese patient, making the higher resolution of TVUS (even with an intact hymen) clinically advantageous.

Pelvis/Perineum US Medical PG Question 5: A 17-year-old girl comes to the emergency department with a 5-day history of severe abdominal pain, cramping, nausea, and vomiting. She also has pain with urination. She is sexually active with one male partner, and they use condoms inconsistently. She experienced a burning pain when she last had sexual intercourse 3 days ago. Menses occur at regular 28-day intervals and last 5 days. Her last menstrual period was 3 weeks ago. Her temperature is 38.5°C (101.3°F), pulse is 83/min, and blood pressure is 110/70 mm Hg. Physical examination shows abdominal tenderness in the lower quadrants. Pelvic examination shows cervical motion tenderness and purulent cervical discharge. Laboratory studies show a leukocyte count of 15,000/mm3 and an erythrocyte sedimentation rate of 100 mm/h. Which of the following is the most likely diagnosis?

• A. Ectopic pregnancy
• B. Ovarian cyst rupture
• C. Pyelonephritis
• D. Appendicitis
• E. Pelvic inflammatory disease (Correct Answer)

Pelvis/Perineum Explanation: ***Pelvic inflammatory disease*** - The constellation of **lower abdominal pain, fever, cervical motion tenderness, purulent cervical discharge, leukocytosis, and elevated ESR** in a sexually active young woman strongly indicates PID. - The history of **pain during intercourse and inconsistent condom use** increases the risk for sexually transmitted infections, which are common causes of PID. *Ectopic pregnancy* - While it can cause unilateral abdominal pain and tenderness, it's typically associated with **amenorrhea** and **vaginal spotting**, neither of which is present, and would not cause purulent discharge or fever this high. - A **positive pregnancy test** would be expected, but none is mentioned, and her last menstrual period was 3 weeks ago, making pregnancy less likely as a cause of such severe symptoms. *Ovarian cyst rupture* - Characterized by **sudden-onset, sharp, unilateral abdominal pain** which may be accompanied by nausea and vomiting, but generally **lacks fever, purulent cervical discharge, cervical motion tenderness, or leukocytosis** as prominent features. - The symptoms in the case, particularly the signs of infection, are inconsistent with a simple cyst rupture. *Pyelonephritis* - Typically presents with **flank pain, fever, dysuria, and CVA tenderness**, often with urinary symptoms like frequency or urgency. - While dysuria is present, the **prominent cervical motion tenderness and purulent cervical discharge** make pyelonephritis less likely as the primary diagnosis, although a co-infection is possible. *Appendicitis* - Causes periumbilical pain that migrates to the **right lower quadrant**, often with anorexia, nausea, fever, and leukocytosis, but **lacks the genitourinary symptoms** such as dysuria, cervical motion tenderness, and purulent cervical discharge. - The patient's pain is described as lower quadrant, which can be diffuse with PID.

Pelvis/Perineum Flashcard 1 of 5

Question: The _____ plexus innervates internal pelvic viscera

Answer: inferior hypogastric

Pelvis/Perineum Flashcard 2 of 5

Question: The _____ is the furthest point of the abdominopelvic cavity in women, and is typically where infections and fluids collect

Answer: Pouch of Douglas

Pelvis/Perineum Flashcard 3 of 5

Question: The _____ muscles hold the bladder and the urethra in the appropriate anatomic position and comprise the pelvic floor

Answer: levator ani

Pelvis/Perineum Flashcard 4 of 5

Question: The inferior rectal artery is a branch of the _____ artery

Answer: internal pudendal

Pelvis/Perineum Flashcard 5 of 5

Question: Which parasympathetics innervate the regions of the hindgut? _____

Answer: Pelvic splanchnic nerves (S2-S4)