Studies available in the epidemiological field have shown that the incidence of breast cancer is increasing with increase in age. The incidence is increasing most likely due to the widespread prevention campaigns and availability of modern diagnostic tools. Presently general anaesthesia is the standard technique used for surgical treatment of breast cancer. Nevertheless, the associated higher stress response, lack of residual analgesia, higher incidence of nausea and vomiting and increasing length of hospitalization demand for an alternative technique. 

Additionally, associated major medical problems are higher in these geriatric age group of patients, which makes regional anaesthesia a preferable option.

The regional anaesthesia techniques can reduce the surgical stress response and can come up with better analgesia with reduction in opioid consumption postoperatively. Moreover, local anaesthetics have direct protective action on cancer cell migration.

Conventionally used regional anaesthesia techniques for breast cancer surgery include thoracic epidural and thoracic paravertebral block. These regional techniques are very productive in the aspect of breast surgery, yet the delayed onset of block, patchy sensory block and large volume of local anaesthetic consumption with the likely local anaesthetic toxicity are even now concerned issues when applying these techniques during breast surgery. 

The blocking of the required dermatomes needed for the proposed surgery could be provided by thoracic segmental spinal anaesthesia with an exceedingly low dose of local anaesthetic. The patients will be having motor control over the limbs, which reduces anxiety and manifest a high level of satisfaction. 

Thomas Jonnesco (1909) introduced to the world the use of general spinal anaesthesia for surgeries of entire body including the skull, head, neck, and the thorax. The punctures were made at a level of spinal column appropriate to the region to be operated upon. Anaesthetic agent used was stovaine solution with addition of strychnine. They conducted high dorsal analgesia in 103 patients for operations in skull, face, Throat, thorax and upper limb. For head and neck procedures, punctures were performed between the 1st and the 2nd thoracic vertebrae, which resulted in good analgesia for the head, neck, and upper limbs. In thoracic area, high dorsal spinal anaesthesia was given for cases such as large extirpation in cancer breast, amputation of breast with extirpation of the axillary gland, extirpation in cystic disease of breast and resection of ribs.

Elakany MH et al, conducted a trial of segmental spinal anaesthesia in patients undergoing breast cancer surgeries and came to the conclusion that segmental spinal anaesthesia has some advantages over general anaesthesia in terms of patient satisfaction, post-operative analgesia, immediate post-operative recovery. 

Paliwal N et al, conducted a trial of segmental thoracic spinal anaesthesia versus general anaesthesia for breast cancer surgery. Author concluded that segmental thoracic spinal anaesthesia provides better satisfaction with better post-operative analgesia & fewer complications as compared to GA.

Mahmoud AAA et al, conducted a feasibility study where he used segmental thoracic spinal anaesthesia at T5 level in healthy patients undergoing breast surgery and concluded that segmental spinal anaesthesia can be used successfully in these patients with minimum hemodynamic instability.

Most important risk factors for post-operative morbidity & mortality are increasing age & associated comorbidities which have been a great challenge to provide perioperative care to the elderly patients. Also, routine use of GA in major surgeries is responsible for increased perioperative complications. Regional anaesthesia (RA) techniques especially neuraxial blockade can improve recovery & minimize adverse effects and perioperative complications. Potential benefits of using neuraxial blockade include decreased cardio-respiratory complications, decreased neuroendocrine response to surgical stress stimuli, better perioperative care & faster recovery of the patient with less incidence of postoperative nausea & vomiting (PONV), prevention of thromboembolic events & early patient mobilization.

Segmental thoracic spinal anaesthesia (STSA), because it is highly selective spinal block has more advantages like better control at the time of both induction & surgical anaesthesia with increased sensory and motor blockade, better cardio-respiratory stability & less requirement of local anaesthetics with reduced risk of toxicity as compared to other RA procedures like lumbar spinal anaesthesia & thoracic paravertebral block (TPVB). 

The current literature review shows only isobaric local anaesthetics have been used in segmental thoracic spinal anaesthesia for breast cancer surgery, the isobaric local anaesthetic drugs are known to produce delayed onset of block with diffuse spread of spinal anaesthesia.

The aim of the current study is to compare block characteristics and outcomes of hyperbaric versus isobaric ropivacaine in patients undergoing unilateral modified radical mastectomy under segmental thoracic spinal anaesthesia in female patients.