The novel use of spinal anesthesia at the mid-thoracic level: a feasibility study

Background
Breast surgery is commonly performed in geriatric patients. In this age group, patients commonly suffer from comorbidities, making regional anesthesia the preferred option during surgery. Recently, segmental thoracic spinal anesthesia for laparoscopic cholecystectomy was tried successfully. Anatomical studies showed that the posterior dural–spinal cord distance is wider at the mid-thoracic region. This encouraged us to test the feasibility of performing spinal anesthesia at the mid-thoracic level for surgeries in the thoracic region, namely breast surgery.
Materials and methods
We performed a prospective feasibility trial including 25 patients, American Society of Anesthesiologists-I (ASA-I), undergoing minor breast surgery (lumpectomy or simple mastectomy) under segmental thoracic spinal anesthesia at T5 level with 1 ml plain bupivacaine (5 mg/ml) and 0.3 ml fentanyl (50 μg/ml). We assessed the number of attempts required, paresthesia during needle insertion, sensory block level, need for supplemental analgesics or general anesthesia, and block-related complications. Hemodynamics as well as patient satisfaction were also recorded.
Results
The block was successful in all patients. A single insertion attempt was needed in 22 (88%) patients. No paresthesia was recorded during needle insertion. The upper sensory level was at T1 (T1–T2) and the lower sensory level at T11 (T11–T12). No additional analgesics or general anesthesia were needed during procedure. Four patients required ephedrine to correct hypotension. Two of these patients developed nausea during hypotension. No other complications were recorded. Total satisfaction was reported by 23 (92%) patients.
Conclusion
Segmental thoracic spinal anesthesia at T5 level in healthy patients undergoing breast surgery can be used successfully with minimal hemodynamic instability. The safety of this technique needs to be confirmed by further studies involving larger number of patients, with comorbid conditions, before it can be advised for routine use.