A 60-year-old, multiparous, woman comes to the physician because of urinary leakage for the past 4 months. She involuntarily loses a small amount of urine after experiencing a sudden, painful sensation in the bladder. She wakes up at night several times to urinate, and she sometimes cannot make it to the bathroom in time. She has diabetes mellitus type 2 controlled with insulin and a history of pelvic organ prolapse, for which she underwent surgical treatment 5 years ago. Menopause was 11 years ago. She drinks 4-5 cups of coffee daily. Pelvic examination shows no abnormalities, and a Q-tip test is negative. Ultrasound of the bladder shows a normal postvoid residual urine. Which of the following is the underlying cause of this patient's urinary incontinence?

Increased detrusor muscle activity

Decreased pelvic floor muscle tone

Increased urine bladder volumes

Recurrent pelvic organ prolapse

A 40-year-old gravida 4 para 2 woman presents with urinary incontinence requesting definitive treatment. She started experiencing urinary incontinence when coughing, laughing, or exercising about three months ago. Symptoms have not improved with behavioral changes or Kegel exercises. Past medical history is significant for her last pregnancy which was complicated by an arrest of descent and a grade 3 episiotomy. She currently takes no medications. A review of systems is significant for constipation for the last few months. Rectal and vaginal exams are normal. Which of the following is the mechanism that underlies the best course of treatment for this patient?

Anatomic elevation of the urethra

Reduction of detrusor muscle tone

Dilation of a urethral or ureteral stricture

Inhibition of DNA gyrase and topoisomerase

A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?

"Can you tell me more about the symptoms you have been experiencing?"

"Does the diarrhea typically precede the constipation, or vice-versa?"

"Is the diarrhea foul-smelling?"

"Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life"

"Are the symptoms worse in the morning or at night?"

Four hours after undergoing an abdominal hysterectomy, a 43-year-old woman is evaluated in the post-anesthesia care unit because she has only had a urine output of 5 mL of blue-tinged urine since surgery. The operation went smoothly and ureter patency was checked via retrograde injection of methylene blue dye mixed with saline through the Foley catheter. She received 2.4 L of crystalloid fluids intraoperatively and urine output was 1.2 L. She had a history of fibroids with painful and heavy menses. She is otherwise healthy. She underwent 2 cesarean sections 8 and 5 years ago, respectively. Her temperature is 37.4°C (99.3°F), pulse is 75/min, respirations are 16/min, and blood pressure is 122/76 mm Hg. She appears comfortable. Cardiopulmonary examination shows no abnormalities. There is a midline surgical incision with clean and dry dressings. Her abdomen is soft and mildly distended in the lower quadrants. Her bladder is slightly palpable. Extremities are warm and well perfused, and capillary refill is brisk. Laboratory studies show: Leukocyte count 8,300/mm3 Hemoglobin 10.3 g/dL Hematocrit 31% Platelet count 250,000/mm3 Serum _Na+ 140 mEq/L _K+ 4.2 mEq/L _HCO3+ 26 mEq/L _Urea nitrogen 26 mg/dL _Creatinine 1.0 mg/dL Urine _Blood 1+ _WBC none _Protein negative _RBC none _RBC casts none A bladder scan shows 250 mL of retained urine. Which of the following is the next best step in the evaluation of this patient?

Return to the operating room for emergency surgery

Perform ultrasound of the kidneys

Administer 20 mg of IV furosemide

Administer bolus 500 mL of Lactated Ringers

A 56-year-old man is brought to the emergency department 25 minutes after he was involved in a high-speed motor vehicle collision where he was the unrestrained passenger. He has severe lower abdominal and pelvic pain. On arrival, he is alert and oriented. His pulse is 95/min, respirations are 22/min, and blood pressure is 106/62 mm Hg. Examination shows severe tenderness to palpation over the lower abdomen and over the left anterior superior iliac spine. There is no limb length discrepancy. Application of downward pressure over the pelvis shows no springy resistance or instability. Rectal examination is unremarkable. A focused assessment with sonography shows no free fluid in the abdomen. There is no blood at the urethral meatus. Placement of a Foley catheter shows gross hematuria. An x-ray of the pelvis shows a fracture of the left pelvic edge. Which of the following is the most appropriate next step in management?

External fixation of the pelvis

A 22-year-old man is rushed to the emergency department after a motor vehicle accident. The patient states that he feels weakness and numbness in both of his legs. He also reports pain in his lower back. His airway, breathing, and circulation is intact, and he is conversational. Neurologic exam is significant for bilateral lower extremity flaccid paralysis and impaired pain and temperature sensation up to T10-T11 with normal vibration sense. A computerized tomography scan of the spine is performed which shows a vertebral burst fracture of the vertebral body at the level of T11. Which of the following findings is most likely present in this patient?

Flaccid paralysis at the level of the lesion

Stress urinary incontinence procedures — USMLE Lesson

💪 Anatomy - Pelvic Floor Power

Pelvic Diaphragm: The primary support "hammock" for pelvic organs.
- Levator Ani: Puborectalis, pubococcygeus, iliococcygeus.
- Coccygeus muscle.
Innervation: Pudendal nerve (S2-S4). Damage during childbirth is a key risk factor for weakness.
Urethral Support: The diaphragm provides a stable suburethral layer, preventing descent during ↑ intra-abdominal pressure.

Pelvic floor muscles: piriformis, coccygeus, levator ani

⭐ The endopelvic fascia provides passive support, while the levator ani provides active, dynamic support. SUI results from failure of one or both systems.

💧 Pathophysiology - Leaky Faucet Logic

The core issue is when intra-abdominal pressure ($P_{abd}$) exceeds urethral closure pressure ($P_{ure}$).

Urethral Hypermobility: Loss of pelvic floor & fascial support.
Intrinsic Sphincter Deficiency (ISD): Weak urethral sphincter muscle.

⭐ Hypermobility causes loss of the posterior urethrovesical angle, preventing the "backboard" support that normally compresses the urethra during stress.

🩺 Diagnosis - The Cough Test

Objective: Directly visualize urine loss with ↑ intra-abdominal pressure.
Setup: Patient in lithotomy or standing position with a comfortably full bladder.
Action & Finding: Patient coughs forcefully. Simultaneous urine leakage from the meatus is a positive test for SUI.

⭐ Delayed or persistent leakage after the cough suggests detrusor overactivity (urgency incontinence), not pure SUI.

🛠️ Management - Sling It Right

Mid-urethral Slings (MUS): Gold standard for SUI due to high efficacy and minimally invasive nature. A synthetic mesh tape is placed under the mid-urethra to provide support during ↑ intra-abdominal pressure.

Procedure	Approach & Mechanism	Key Complications
Retropubic (TVT)	Mesh passes behind pubic bone. "Top-down" or "bottom-up".	Bladder/bowel perforation, voiding dysfunction, hematoma.
Transobturator (TOT)	Mesh passes through obturator foramen, avoiding retropubic space.	Groin/thigh pain (obturator nerve), less bladder injury.
Burch Colposuspension	Abdominal approach. Sutures attach paraurethral tissue to Cooper's ligament.	Higher surgical morbidity, posterior prolapse, de novo urgency.

⭐ The choice between Retropubic (TVT) and Transobturator (TOT) slings involves a trade-off: TVT offers slightly higher cure rates but with an increased risk of bladder perforation and postoperative voiding dysfunction.

Retropubic vs. Transobturator Sling: Pros & Cons for SUI

⚠️ Complications - Post-Op Pitfalls

Urinary Retention: Common, often transient. May require temporary catheterization if post-void residual (PVR) is high.
De Novo Urgency: New onset urge incontinence. Manage with behavioral therapy, anticholinergics, or beta-3 agonists.
Mesh Complications (Slings): Erosion into vagina/bladder, chronic pain, infection, dyspareunia.
Intra-op Injury: Bladder (most common), urethra, bowel, vascular.
Persistent/Recurrent SUI: Procedure failure.

⭐ Bladder injury is the most common intraoperative complication of retropubic mid-urethral slings. Suspect with post-op hematuria or inability to void. Confirm with cystoscopy.

⚡ Biggest Takeaways

SUI results from urethral hypermobility or intrinsic sphincter deficiency (ISD).

Mid-urethral slings (MUS) are the gold standard, supporting the mid-urethra.

Retropubic (TVT) slings risk bladder/vascular injury; Transobturator (TOT) slings risk groin pain/nerve injury.

Burch colposuspension attaches the vagina to Cooper's ligament; less common now.

Urethral bulking agents are a less invasive option for poor surgical candidates or ISD.

Key complications: urinary retention, mesh erosion, de novo urgency.

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