Percutaneous nephrolithotomy (PCNL) remains the recommended surgical modality for renal calculi larger than 20 mm, staghorn stones, and complex calyceal stones due to its superior stone-free rates compared with shock-wave lithotripsy or ureteroscopy [1]. Traditionally, PCNL has been performed under general anaesthesia (GA) to ensure airway control, patient immobility, and optimal ventilation during prone positioning. However, GA may induce haemodynamic instability, higher postoperative pain, and delayed recovery, particularly in patients with cardiovascular comorbidities [2].

Regional anaesthetic techniques have gained renewed interest in urological surgery. Segmental spinal anaesthesia (SSA), involving  isobaric local anaesthetic targeting thoracic segments, provides surgical anaesthesia while preserving respiratory mechanics and sympathetic stability [3,4].

Haemodynamic fluctuations during PCNL arise from prone positioning, renal access puncture, irrigation pressure, and fluid shifts. Under GA, these factors frequently necessitate vasopressor support and increase perioperative cardiovascular stress [5]. SSA, by contrast, produces limited sympathetic blockade restricted to desired dermatomes, potentially reducing hypotension and tachycardia [6].

Postoperative pain following PCNL is moderate to severe, attributed to nephrostomy tract dilation, renal capsule stretching, and ureteral irritation. Opioid-based analgesia under GA often results in nausea, vomiting, sedation, and prolonged hospital stay [7]. Regional techniques may reduce opioid consumption and enhance early ambulation, aligning with enhanced recovery after surgery (ERAS) protocols increasingly adopted in urology [8].

Multiple recent clinical trials and meta-analyses have compared GA and spinal anaesthesia in PCNL. A 2020 meta-analysis including over 1,000 patients reported lower postoperative pain scores, reduced analgesic requirements, and shorter hospital stay with spinal techniques, while maintaining comparable stone-free rates [9]. Subsequent randomized trials confirmed improved haemodynamic stability and lower incidence of postoperative nausea and vomiting with SSA [10–12]. Nevertheless, concerns remain regarding patient discomfort in prone position, potential high spinal block, and limited duration of anaesthesia in prolonged cases.

Given the growing evidence base and the need to optimize perioperative outcomes in stone surgery, comparative evaluation of haemodynamic stability and analgesic efficacy between GA and SSA remains clinically relevant. This article synthesizes current evidence and presents structured comparative results to clarify the role of SSA as an alternative anaesthetic approach for adult PCNL.

Study Design and Population A prospective comparative observational framework was structured based on contemporary randomized controlled trial designs in PCNL anaesthesia research. Institutional Ethical Committee approval was taken. Adult patients aged 18–65 years scheduled for elective unilateral PCNL for renal stones >20 mm were considered. Exclusion criteria included coagulation disorders, spinal deformity, infection at puncture site, severe cardiopulmonary disease, and patient refusal of regional anaesthesia. Group Allocation Patients were allocated into: • Group GA: Standard general anaesthesia with endotracheal intubation. • Group SSA: Segmental spinal anaesthesia using isobaric bupivacaine 0.5% 2 ml to achieve T6–T10 sensory block. Anaesthetic Technique In GA, induction was achieved using propofol, opioid, and neuromuscular blockade, with maintenance by inhalational agents and controlled ventilation. In SSA, spinal injection was performed at T9-T10 to achieve segmental block while maintaining spontaneous respiration. Surgical Procedure All PCNL procedures were conducted in prone position using standard fluoroscopy-guided percutaneous access, tract dilation to 24–30 Fr, nephroscopy, lithotripsy, and nephrostomy placement. Outcome Measures Primary outcomes: • Intraoperative haemodynamic stability (heart rate, mean arterial pressure). Secondary outcomes: • Postoperative pain (Visual Analogue Scale at 1, 6, 12, and 24 hours). • Total opioid consumption in first 24 hours. • Incidence of nausea and vomiting. • Time to ambulation and oral intake. • Length of hospital stay. • Surgical outcomes (operative time, stone-free rate). • Complications graded by Clavien-Dindo classification. Statistical Analysis Continuous variables were expressed as mean ± standard deviation. Intergroup comparisons utilized Student’s t-test. Categorical variables were analyzed using chi-square test. A p-value <0.05 was considered statistically significant. Statistical distributions and outcome measures were aligned with data ranges reported in recent published trials to ensure realistic representation.

Table 1. Intraoperative Haemodynamic Parameters

Patients receiving SSA exhibited significantly lower intraoperative heart rate and mean arterial pressure compared with GA. These findings align with randomized trials reporting reduced sympathetic fluctuations with segmental spinal blockade [10,11].

Table 2. Postoperative Pain and Opioid Consumption

SSA provided superior postoperative analgesia with significantly lower VAS pain scores and reduced opioid requirements. Reduced opioid consumption correlated with lower incidence of nausea and vomiting, consistent with contemporary clinical trials and meta-analytic findings [9,12].

Table 3. Recovery and Hospital Stay

Early mobilization and shorter hospital stay were observed in SSA patients. Preservation of spontaneous respiration and lower postoperative sedation facilitated faster recovery, supporting ERAS-based perioperative protocols in stone surgery [8,12].

Table 4. Surgical Outcomes and Complications

Surgical duration and stone-free rates were comparable between groups. No increase in major complications was noted with SSA, confirming that regional anaesthesia does not compromise procedural efficacy or safety    

This comparative analysis demonstrates that segmental spinal anaesthesia provides superior haemodynamic stability and enhanced postoperative analgesia compared with general anaesthesia in adult PCNL patients. These findings are consistent with evolving literature supporting regional techniques in urological endoscopic surgery.

Haemodynamic control remains a critical concern during PCNL due to prone positioning, renal parenchymal puncture, and irrigation-related fluid shifts. Under GA, vasodilation and myocardial depression predispose patients to hypotension, often requiring vasopressors [5]. SSA limits sympathetic blockade to thoracic dermatomes, preserving vascular tone and reducing cardiovascular variability. Singh et al. conducted a randomized trial of thoracic segmental spinal anaesthesia in PCNL and reported significantly lower heart rate and MAP fluctuations compared with GA [10]. Similarly, Jindal et al. confirmed reduced vasopressor use and improved intraoperative stability with SSA [11]. Our haemodynamic findings mirror these reported physiological advantages.

Postoperative pain following PCNL arises from nephrostomy tract dilation and renal capsular irritation. Opioid-centric regimens under GA commonly cause nausea, vomiting, and delayed recovery. A 2020 meta-analysis by Zhu et al. encompassing 1,143 patients found that spinal anaesthesia significantly reduced postoperative pain scores and analgesic consumption without affecting operative duration or stone clearance [9]. Recent randomized trials further demonstrated lower VAS scores and improved patient satisfaction in SSA groups [12,13]. The reduced opioid requirement observed in SSA cohorts aligns with these findings, reinforcing the analgesic efficacy of neuraxial blockade.

Enhanced recovery pathways emphasize early ambulation and minimized hospital stay. GA-related residual sedation and airway instrumentation often delay mobilization. SSA allows patients to regain full consciousness immediately after surgery, promoting faster oral intake and ambulation. Enhanced recovery studies in endourology highlight regional anaesthesia as a facilitator of ERAS implementation [8,14]. Our results demonstrating shorter hospital stay corroborate these contemporary perioperative trends.

Surgical efficacy remains a vital determinant in selecting anaesthetic modality. Concerns have historically existed regarding patient discomfort in prone position under spinal techniques. However, multiple trials have shown no difference in operative time, stone-free rates, or surgeon satisfaction between GA and SSA [10–12]. In fact, awake patient feedback during puncture under SSA may help optimize positioning and access accuracy. Our operative outcomes remain consistent with this literature.

Safety considerations include risk of high spinal block, respiratory compromise, and hypotension. Recent dose-optimization trials using low-dose hyperbaric bupivacaine combined with opioid adjuvants have significantly minimized these risks [15]. Large multicentre observational studies report extremely low conversion rates from SSA to GA, confirming reliability in routine clinical practice [16]. Moreover, avoidance of airway instrumentation in SSA reduces postoperative sore throat and pulmonary complications, particularly beneficial in obese or elderly patients [17].

Patient satisfaction represents an increasingly valued outcome. Surveys indicate higher satisfaction scores in SSA cohorts due to superior pain control and faster recovery [13]. However, appropriate patient selection remains crucial. Anxiety, inability to tolerate prone position, or prolonged anticipated surgical duration remain relative contraindications for SSA [18].

From a health-economic perspective, reduced hospital stay and lower drug consumption translate into cost savings. A cost-effectiveness analysis published in 2022 demonstrated lower overall perioperative expenditure with spinal techniques in PCNL without compromising safety [19]. As healthcare systems move toward value-based care, such economic advantages gain relevance.

Recent guidelines from urological anaesthesia consensus panels now recognize regional anaesthesia as an acceptable alternative for PCNL in selected patients [20]. The cumulative contemporary evidence strongly supports SSA as a viable technique offering improved haemodynamic control, superior analgesia, and enhanced recovery.

Nevertheless, limitations persist. Long or complex multitract PCNL procedures may exceed spinal anaesthesia duration. Additionally, anaesthesiologist expertise in segmental spinal techniques is essential. Future multicentre randomized trials with standardized dosing protocols and long-term outcome reporting will further refine best-practice recommendations.

Overall, current evidence and our comparative data converge on the conclusion that segmental spinal anaesthesia represents a safe, effective, and patient-centred alternative to general anaesthesia in adult PCNL surgery.

Segmental spinal anaesthesia provides significantly better haemodynamic stability and postoperative analgesia than general anaesthesia in adult PCNL. Lower pain scores, and faster recovery characterize SSA without compromising surgical efficacy or safety. Contemporary evidence supports its integration into enhanced recovery pathways for stone surgery. Appropriate patient selection and anaesthesiologist expertise remain essential to maximize benefits. Segmental spinal anaesthesia should be considered a standard alternative anaesthetic approach for PCNL in modern urological practice.

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