Monday, March 8, 2010

PCNL:RIGHT TECHNIQUE AND OVERVIEW

The surgical management of urinary calculus disease has evolved considerably over the past two decades. Twenty years ago, open procedures for stones were some of the most frequently performed urologic operations. Since then, however, stone management has been at the fore-front of “minimally invasive” intervention. The introduction and refinement of percutaneous and ureteroscopic access to the upper tracts, along with the nearly simultaneous development of both extracorporeal and intracorporeal lithotripsy, has relegated the role of open surgery to less than 1% of patient undergoing intervention for their stone disease(some of the superspeciality students in corporate hospitals are not even exposed to open pyelolithotomies and nephrolithotomies).
The rapid acceptance and widespread use of ESWL has made this form of stone therapy the treatment of choice for more than 50% of all patients undergoing intervention for renal and ureteral calculi. However, not all stones are amenable to ESWL and clinical studies have demonstrated that the size and composition of calculi, along with location and renal and ureteral anatomy all significantly affect successful stone fragmentation and clearance.
The percutaneous stone extraction gained acceptance as the procedure of choice for management of most patients with upper tract calculi in the late 1970’s and early 1980’s. In 1987, Leroy et al at the Mayo clinic reported a contemporary experience with percutaneous stone management in the era of ESWL. The authors concluded that despite the increased complexity of patients undergoing percutaneous management, excellent result could still be achieved with acceptably low morbidity.
Indications for PCNL
• Renal calculi greater than 2 cms in diameter.
• Stone with composition inappropriate for ESWL(lower calyceal stone more than 1.5 cm in size).
• Renal malformations like infundibular stenosis, pelvi - ureteric Junction obstruction.
• Failure of ESWL.
• ESWL not suitable because of problems in focussing For ex.Kyphoscoliosis
The patient needs to undergo pre operative workup as required in open operation and Urine culture should be treated with antibiotics, the PCNL procedure is done with help of imaging "C" Arm under spinal anaesthesia.Intra-venous Pyelography is a must as most of the urologists decide pre-operatively the puncture and access.Often even with the development of CT urography the IVP has been a favourite with all urologists.
Technique of Percutaneous Nephrostomy
Initial step of PCNL is cystoscopy and placement of an open ended or ureteric catheter on the side of the stone and injecting dye which will give the configuration of the pelvi-calyceal system. Under the general anesthesia in lithotomy position, retrograde ureteric catheterization was done in all the patients. Later the position was changed to prone and desired calyceal puncture was made under fluoroscopic guidance with the help of retrograde instillation of dye in the pelvi-calyceal system. The initial puncture was decided on table based on the location of the stone bulk and the abnormal anatomy, to access the maximal stone bulk, after a retrograde pyelography. After the initial puncture the gradual dilatation was carried out with the fascial dilators with intermittent fluoroscopic guidance till 16 Fr Amplatz sheath fits in. A Karl Storz 15Fr miniature nephroscope (Karl-Storz) was used in majority cases.In staghorn calculi,conentional PCNL with 26 fr Amplatz was done. The stone fragmentation was done with pneumatic lithotripter. When multiple tracts were needed (the need was assessed prior to puncture), multiple punctures were made initially in the desired calyces and guide wires were left in situ for dilatation as need arises.

Standard Puncture
The puncture is made with needle and help of "C" Arm. Once the needle is in pelvicalyceal system, a J tipped, Teflon coated movable core guidewire is negotiated into the renal pelvis and across the Pelviureteric Junction into the ureter.The position of the guide wire is confirmed both in 0 and 90 degrees rotation of the C-arm so that misguided dilatation and resultant extravasation o bleeding will not occur.


Tract Dilatation
Dilatation need to be done under fluoroscopy to see that it is along the guide wire and it should not be bent during the process of dilatation.

We use miniature nephroscope so that the dilataton is done till 16 Fr over guide rod followed by Karl Storz mini-nephroscope is inserted.


Stone fragmentation:


Renal pelvis is flushed with irrigant through thesheath or from below by open ended catheter. Once the stone is visible, with the Holmium LASER fragmentation is carried out.The LASER often makes up for shortcomings of the the miniature nephrosocpy.The pulverisation is fast.






Larger stone burden/Bleeding/Infective pelvis:
In such cases we always stage the procedure.Keep he nephrostomy tube after clearaing as much as stone possible followed by relook after 3-4 days.


Final steps
By fluoroscopy and nephroscopy the pelvicalyceal system is checked for residual fragments and once all the stones are removed, a Devon nephrostomy tube is passed through Amplatz sheath as a nephrostomy.The radio-opaque tube tip helps in keeping the tube tip in right place and direction. Nephrostomy tube is clamped and removed after 24 hrs. and patient is discharged the next day.









Complication
1. Meticulous technique is necessary to minimize the complication of PCNL. It is a minimally invasive procedure but can have deadly complications. Bleeding from renal parenchyma occurs to some degree due to extremely vascular nature of the kidney, about 2-5% of patients may need blood transfusion.Less than 0.5% patients need extra-intervention like angioembolisation.Precise puncture,controlled dilatation are the keys to prevent bleeding which may sometimes be torrential.
2. Infection, fever or urosepsis is minimized by routine prophylaxis with broad specturm IV antibiotics.But sometimes the sepsis becomes evident only after puncture with pus draining out.If it is frank pus the procedure can be staged to avoid full-fledged septicemia.
CONCLUSION
PCNL is a boon to urologists and patients with complex stone burden.Small stay,small wound and early recovery are the advantages.Earlier day Anatrophic nephrolithotomies now appear as Nightmares to new urologists with the advent of even Miniature PCNLs.The only key is precise calyceal puncture ,avoid infundibulum, confirmation of needle position in two angles preferably 0 and 90 degrees(more safe).If possible guidewire placement in the ureter.The dilatation should be smooth and controlled not jerky(proper pre-operative fasciotomy with the artery forceps aids in dilatation as shown in the video).Holmium LASER and miniPCNL help in reduction of morbidity in terms of pain,bleeding and early recuperation.



2 comments:

  1. great subject
    but where is the video? please

    ReplyDelete
  2. What is your laser setting for PCNL?

    Any tips on puncture techniques - bullseye vs triangulation

    ReplyDelete