Considerations for Subtotal or Near-Total Excision Procedures
Subtotal or near-total excision procedures should be considered when complete resection poses significant risk to critical structures, with the understanding that residual tumor volume directly correlates with recurrence rates. 1
Vestibular Schwannomas
Extent of Resection and Recurrence Risk
- Goal of surgery should be total or near-total resection since residual tumor volume correlates with rate of recurrence (evidence class III, recommendation level B) 1
- Recurrence rates vary significantly based on extent of resection: gross total resection (3.8%), near-total resection (9.4%), and subtotal resection (27.6%) 1
- Patients with subtotal resection experience recurrences over 13 times more often than those treated with near-total resection 1
- Near-total resection via an enlarged translabyrinthine approach has shown lower rates of regrowth compared to subtotal resection 2
Functional Preservation vs. Complete Removal
- For large vestibular schwannomas, the lower risk of recurrence after gross total resection must be weighed against higher risk for facial nerve dysfunction and lower rates of hearing preservation 1
- Partial resection followed by stereotactic radiosurgery has become increasingly popular for large vestibular schwannomas 1
- This combined approach shows superior outcomes for facial nerve function and hearing preservation compared to total resection, with comparable tumor control rates 1
Follow-up After Incomplete Resection
- After intentional near-total or subtotal resection, a watch and scan policy is warranted as only a minority of remnants progress 1
- Risk of progression increases with the size of the remnant 1
- For recurrences after radiosurgery, both reoperation and radiosurgical retreatment are possible options 1
Neuroendocrine Tumors
Surgical Approach
- For symptomatic recurrence from local effects or hormone hypersecretion, subtotal resection of a large proportion of the tumor (typically >90%) can effectively palliate symptoms 1
- Planned cytoreductive, incomplete (R2) resection of advanced disease in patients with asymptomatic or nonfunctional disease remains controversial 1
Rectal Cancer
Quality of Mesorectal Excision
- The quality of mesorectal excision is graded based on the plane of surgical excision: mesorectal plane (good), intramesorectal plane (moderate), and muscularis propria plane (poor) 1
- A good quality total mesorectal excision shows intact mesorectum with only minor irregularities, no defect deeper than 5 mm, no coning, and smooth circumferential resection margin 1
Partial Mesorectal Excision
- A partial mesorectal excision with a distal margin of at least 5 cm of mesorectum can be considered in high rectal cancer 1
- Standard of care for surgery is total mesorectal excision (TME), implying that all mesorectal fat, including all lymph nodes, should be meticulously excised 1
Low-Grade Gliomas
Treatment After Subtotal Excision
- Patients who only had a stereotactic biopsy, open biopsy, or subtotal excision should be treated with immediate fractionated external beam radiation therapy or chemotherapy (category 2B), particularly if symptoms are uncontrolled or progressive 1
- Patients with asymptomatic residual tumors or stable symptoms may be followed until disease progression 1
- Follow-up should include MRI every 3-6 months for 5 years, and then at least annually 1
Crohn's Disease
Surgical Options
- Segmental colectomy is appropriate for patients with a single involved colonic segment in Crohn's disease 1
- When multiple segments are involved, subtotal/total colectomy with ileorectal anastomosis is generally indicated 1
- A defunctioning stoma for non-acute refractory Crohn's colitis may delay or avoid the need for colectomy 1
Common Pitfalls and Considerations
Risk Assessment
- Experience of the surgical team is an important factor affecting outcomes, suggesting that procedures should be performed in high-volume centers (evidence class IV, good practice point) 1
- Intraoperative monitoring is mandatory for surgery of vestibular schwannomas and should include somatosensoric evoked potentials and monitoring of the facial nerve 1
- For large lesions, electromyography of the lower cranial nerves is recommended (evidence class IV, good practice point) 1
Balancing Risks and Benefits
- The functional risk for the facial nerve upon reoperation is higher after previous irradiation, requiring a very meticulous, conservative dissection technique 1
- In vestibular schwannomas recurring after surgery, radiosurgery may be preferred because the risk of damage to the facial nerve is lower than with a second operation 1
- For colloid cysts, even a subtotal excision may be acceptable when experience with the endoscope is limited, as these are slow-growing lesions 3