Supine PCNL in Flank-Free Oblique Supine Modified Lithotomy (FOSML) Position: Our Point of Technique

Objective: There are various positions described for supine PCNL but ideal position for supine PCNL remains debatable. To describe technique of Percutaneous Nephrolithotomy in Flank-free Oblique Supine Modified Lithotomy (FOSML) Position. Material and Method: Patients with Renal stones >1cm were selected to undergo Percutaneous Nephrolithotomy. After due approval from Research review committee and necessary informed consent, patients were taken up for surgery and given Spinal or General anaesthesia. First standard lithotomy position was given and torso of patient was turned lateral to opposite side. Shoulders remain perpendicular to table and supported by backrest. Ipsilateral Buttock allowed to rest on an inflatable Gel pad and ipsilateral leg extended at the hip to open up the flank. Gel pad under buttock, is inflated to get desired elevation of flank. Final position is Flank free Oblique Supine Modified lithotomy Position. Result: This position helps in quick positioning after anaesthesia induction. One time painting and draping required for entire surgery and simultaneous lower tract (for cystoscopy and ureteric catheterization) and upper tract (puncture and stone removal) access is possible throughout the surgery. This position gives all the advantages of other supine PCNL positions while overcoming limitations like difficult superior calyceal access or spine superimposition. Conclusion: This position is easy and uncomplicated with various advantages over previously described positions for supine PCNL. We have found it as most versatile position in terms of stone access (both antegrade & Retrograde) and access to superior calyx