Chinese Expert Consensus on Standardized Treatment for Presacral Cysts (2023)

Abstract

1. Origin and Pathology

Etiology

• Derived from incompletely degenerated embryonic structures: tailgut, neurenteric canal, primitive streak.
• Tailgut cysts (most common): polycystic, lined with gastrointestinal epithelium; contain clear/yellowish viscous fluid.

Classification

• Benign: Epidermoid cyst, dermoid cyst, enteric cyst (tailgut cyst, cystic rectal duplication), neurenteric cyst, teratoma.
• Malignant: Rare; may arise from malignant transformation of benign cysts.

2. Diagnosis

Clinical Manifestations

• Asymptomatic (incidental finding) or nonspecific: sacrococcygeal pain, defecation dysfunction, perianal mass, recurrent infection.
• Malignant features: intractable pain, bone destruction, invasion of adjacent organs.

Imaging

• MRI (gold standard): Defines cyst location, size, relationship to sacrum/rectum/sphincter; distinguishes benign vs. malignant.
• CT: Evaluates bone involvement and calcification.
• Ultrasound: Initial screening; transrectal/transperineal for deep lesions.

Biopsy

• Routine needle biopsy not recommended (risk of infection/sinus formation).
• Biopsy only for suspected malignancy (intractable pain, bone destruction, MRI invasion) to guide treatment.

3. Surgical Principles

Core Goal

Indications for Surgery

• Symptomatic cysts (pain, defecation disorder, infection).
• Asymptomatic cysts >3 cm or growing.
• Suspected malignant transformation.

Contraindications

• Severe comorbidities precluding surgery.
• Benign, small, asymptomatic cysts in elderly/frail patients.

4. Surgical Approaches (Recommended)

Transperineal Approach (Preferred for Low Cysts)

• Longitudinal incision: For cysts with upper pole <S4; jackknife position; incision along gluteal sulcus; resect coccyx for exposure.
• Transverse arc incision: For larger low cysts; coccyx as landmark; better exposure for eccentric lesions.
• Intersphincteric incision: For cysts adjacent to anal canal; preserves sphincter function.

Transabdominal Approach

• For high cysts (upper pole >S4) or large/complex lesions; laparotomy or laparoscopy; mobilize rectum, dissect presacral space.

Combined Transabdominal–Transperineal Approach

• For giant, multilocular, or recurrent cysts; optimal exposure for complete resection.

Key Technical Points

• Preserve Waldeyer fascia and presacral fascia to avoid nerve/vessel injury.
• Protect sacral nerves (S3–S5) to prevent incontinence/sexual dysfunction.
• For cyst–rectal fistula: resect fistula tract; use gluteal muscle flap for repair; avoid routine diverting stoma.

5. Perioperative Management

Preoperative

• Bowel preparation; broad-spectrum antibiotics; MRI for surgical planning.
• Multidisciplinary discussion (surgery, gynecology, orthopedics, radiology, pathology) for complex cases.

Intraoperative

• Frozen section for suspected malignancy; extend resection if malignant.
• Hemostasis: preserve middle sacral artery; use electrocautery/hemostatic agents.

Postoperative

• Drainage: closed suction for 3–5 days; monitor for infection/hematoma.
• Complications:
  • Infection: Antibiotics; debridement if abscess.
  • Fecal incontinence: Pelvic floor rehabilitation; sacral nerve stimulation if severe.
  • Recurrence: Re-resection with wider margins.
   

6. Follow-Up

Benign Cysts

• Every 6 months for 2 years; annually thereafter.
• Imaging: MRI/CT/ultrasound to detect recurrence.

Malignant Cysts

• Every 3 months for 2 years; every 6 months thereafter.
• Multidisciplinary adjuvant therapy (radiation/chemotherapy) as indicated.

7. Key Recommendations

1. Complete resection is mandatory for cure; avoid incomplete removal.
2. MRI is essential for preoperative planning.
3. Transperineal approach is first-line for low cysts; transabdominal for high lesions.
4. Preserve sacral nerves and sphincter to maintain function.
5. Multidisciplinary care improves outcomes for complex/malignant cases.