Air Pyelogram for Percutaneous Nephrolithotomy in Patients with Iodinated Contrast-induced Anaphylaxis

Abstract

Percutaneous nephrolithotomy (PCNL) is the preferred treatment for large renal calculi. Fluoroscopic access conventionally requires iodinated contrast, which may precipitate anaphylaxis in sensitized individuals. We report two cases of contrast-induced anaphylaxis, in which air pyelography was successfully used to delineate the pelvicalyceal system and obtain safe renal access during PCNL.

INTRODUCTION

Iodinated contrast media are widely used during endourological procedures. Although nonionic agents have reduced adverse reactions, anaphylaxis remains a serious complication. Alternative imaging techniques such as air pyelography and ultrasonography (USG) are valuable in high-risk patients.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25]

CASE REPORTS

Case 1

A 43 year old male patient with Right Renal pelvic calculus of size 16mm was planned for procedure of right Pcnl.During procedure patient developed severe hypotension and bronchospasm following intraoperative retrograde pyelography with iohexol. After stabilization, percutaneous nephrolithotomy (PCNL) was successfully performed using air pyelography for access in later procedure [Figures 1-4].

Figure 1.

Three dimensional Reconstructed CT image of Bilateral Kidneys and Urinary Bladder of Case 1

Figure 4.

Plain Xray Image Of Bilateral Kidney,Ureter and Urinary Bladder of Case

Figure 2.

Axial CT image of Bilateral Kidneys of Case 1

Figure 3.

Coronal CT image of Bilateral Kidneys,Ureter and Urinary Bladder of Case 1

The patient underwent cystoscopy + right DJ stenting on 14/4/2025.

5 Fr ureteric catheter could not be placed beyond the distal ureter.

Right check ureterorenoscopy (URS) was done. An unaccommodating, slightly narrow ureter was noted, and URS could not be negotiated above.

Right RIRS with the option to proceed to Right PCNL if required under GA was planned post DJ stenting on May 7, 2025.

The access sheath could not be negotiated over the guidewire into the right ureter.

4/70 ureteric catheter was placed over 0.025 inch guidewire into the right ureter up to the right kidney due to a narrow ureter.

Retrograde pyelography was done with 10cc iohexol + NS contrast (1:3).

The patient was about to be proned, but sudden hypotension (blood pressure – 60/40 mmHg) with tachycardia (120/min) and bronchospasm ensued.

Resuscitation was started with adrenaline, hydrocortisone, and intravenous fluids, and the patient was stabilized.

Procedure abandoned and right 4/26 Dj stent was placed.

Consultations and interdepartmental clinical meetings were held postoperatively with the department of anesthesiology and the department of dermatology to ascertain the cause of anaphylactic reaction.

Iohexol dye was determined as an allergic agent after ruling out anesthetic drugs such as propofol, nitrous oxide, and midazolam given during the procedure. Prior sensitization during computed tomography (CT) urography was also considered a contributory factor.

The patient was posted for PCNL on June 11, 2025, keeping the above in mind, with air pyelogram or USG-guided puncture as alternatives for puncture access.

Cystoscopy was done, and previous DJ stent was removed.

5/70 ureteric catheter was placed in the right ureter, and an air pyelogram was done with 5cc air in the supine position.

The patient turned to the prone position, and a lower calyceal puncture was taken after access was determined by PCS (PelviCalyceal System) opacification with air.

Guidewire was placed, and tract was dilated up to 22Fr by Seldinger approach.

Using a nephroscope, lithotripsy was done, fragments were removed, and 5/24 DJ stent was placed [Figure 5 and Video 1].

Figure 5.

Post PCNL Plain Xray Image Of Bilateral Kidney,Ureter and Urinary Bladder of Case 1

Case 2

A 61-year-old male with documented iodinated contrast anaphylaxis during CT urography which showed 15mm Right Renal middle calyceal calculus [Figures 6-10] underwent PCNL using an air pyelogram, resulting in complete stone clearance without complications. The patient planned for right prone PCNL.

Figure 6.

Anaphlyactic reaction Incident Identity Card of Case 2

Figure 10.

Three dimensional Reconstructed CT image of Bilateral Kidneys and Urinary Bladder of Case 2

Figure 7.

Patient of Case 2 showing skin reaction post Contrast CT scan

Figure 8.

Axial CT image of Bilateral Kidneys of Case 2

Figure 9.

Coronal CT image of Bilateral Kidneys,Ureter and Urinary Bladder of Case 2

Cystoscopy done

• 5/70 ureteric catheter was placed in the right ureter, and an air pyelogram was done with 5cc air in the supine position [Figure 11].

• The patient turned to the prone position, and stone-guided puncture was taken after access was determined by PCS opacification with air.

• Guidewire was placed, and tract was dilated up to 22Fr by Seldinger approach [Figure 12].

• Using a nephroscope, lithotripsy was done, fragments were removed, and a 5/24 DJ stent was placed [Figure 13 and Video 2].

Figure 11.

Preoperative C-arm Xray image of Case 2

Figure 12.

Intraoperative C-arm Xray image of case 2

Figure 13.

Post Operative C-arm Xray image after stone removal of case 2

DISCUSSION

Air pyelography preferentially outlines posterior calyces in the prone position, aiding accurate puncture while avoiding contrast exposure. Radiation exposure may also be reduced. Although venous air embolism has been reported, the risk is extremely low when appropriate precautions are followed.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25]

CONCLUSION

Air pyelogram is a safe and effective alternative to iodinated contrast during PCNL in patients with contrast-induced anaphylaxis.[21,22,23]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.