2DNB (Diplomat of national board), Urology, Muljibhai Patel Urological Hospital, Gujarat 387001, India.
You are watching: What does pcn mean in medical terms
3Department of Urology and Renal Transplant, Muljibhai Patel Urological Hospital, Gujarat 387001, India.
Correspondence Address: Dr. Arvind Ganpule, DNB (Diplomat of national board), Urology, Muljibhai Patel Urological Hospital, Nadiad, Gujarat 387001, India. E-mail: doctorarvind1
Received: 10 Jul 2017 | First Decision: 1 Sep 2017 | Revised: 30 Sep 2017 | Accepted: 11 Oct 2017 | Published: 28 Dec 2017
This is an open access article licensed under the terms of Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original author is credited and the new creations are licensed under the identical terms.
Percutaneous renal access remains the cornerstone initial step in varied clinical settings. For obtaining the best surgical outcome and minimizing patient morbidity, an appropriate access to the target calyx is needed. Though the site of entry depends upon anatomy of pelvicalyceal system and indication for access, a proper technique should be used for gaining access and at the same time minimizing the associated complications. This article describes our technique of gaining access to the pelvicalyceal system and subsequent percutaneous nephrostomy placement in a stepwise manner. Percutaneous nephrostomy, ultrasound, hydronephrosisPercutaneous nephrostomy (PCN) is a widely used interventional procedure for upper urinary diversion and decompression of the renal collecting system in varied clinical settings. Despite it being a basic urological procedure, it remains technically challenging to insert it in the right way and in the right place. Most of the time it’s because of lack of exposure of the urologist/interventional radiologist to correct technique of PCN placement in a stepwise manner. Goodwin et al.<1> first reported placement of percutaneous trocar (needle) nephrostomy in a hydronephrotic kidney. Since then, many direct and wire guided methods of PCN placement has been elucidated in literature. PCN can be done under flouroscopy, ultrasound (USG) or computed tomography guidance. In this chapter we will describe the USG guided technique of PCN placement in a stepwise manner which is safe, effective and easily reproducible.
Benign causes: impacted ureteric/pelvis calculi with secondary hydronephrosis (HN), uretericstricture disease, pelvic ureteric junction obstruction, HN associated with pregnancy, in transplant patients (e.g. HN due to anastomotic stricture), retroperitoneal fibrosis, urosepsis, pyonephrosis. Malignant causes: HN secondary to tumor of urinary tract, HN secondary to carcinoma cervix/prostate<2,3>.
Urinary diversion in an attempt to heal conditions such as malignant/inflammatory fistula, urinary leak or fistulas resulting from trauma, and hemorrhagic cystitis etc.<2,3>.
For providing route of access
Chemotherapy, antifungal/antibiotic therapy, benign stricture dilatation, antegrade ureteral stent placement, stone retrieval, endopyelotomy<2,3>.
Pre-operative preparation and a counseling of the patient
Commonly, this procedure is done in local anesthesia (LA). Patient should be well explained about the procedure in detail. Informed consent should be taken beforehand. Bleeding parameters should be within normal limits. Attain intravenous (IV) access and antibiotics should be given half an hour prior to procedure particularly particularly in patients presenting with urosepsis. For uncooperative but willing patient, procedure should be performed under general anesthesia. Relevant radiological images should be reviewed again in order to decide anoptimal approach for renal access.
Step 1: patient positioning
With patient in prone position, a roller pack is placed underneath pelvic bone and another under upper abdomen and chest region (as shown) so as to give adequate stretching around flank region<4,5>. The side to be operated should be brought at the edge of operating table. The area should be cleansed with povidone iodine and draped
Figure 1. The patient in prone position with roller pack underneath upper abdomen and chest, abdominal contents falls forward so as to give proper access to the kidneys
Step 2: surface marking
If we place PCN in quadrangle of safety formed by posterior axillary line as lateral limit, upper margin of iliac crest as lower limit, lateral margin of paraspinous muscle as medial limit, the 11th and 12th rib border as upper limit, there are less chances of associated intrabdominal visceral injuries
Figure 2. Surface marking (concept of Quadrangle of safety): with the patient in prone position, Quadrangle of safety is formed by posterior axillary line as lateral limit, upper margin of iliac crest as lower limit, lateral margin of paraspinous muscle as medial limit, the 11th and 12th rib border as upper limit
Step 3: USG to decide site of percutaneous puncture
USG of the diseased kidney should be done starting from medial aspect (Para spinal), advancing laterally until the posterior axillary line so as to see posterior calyces first followed by lateral calyces thereafter and thus to have an idea of degree of HN, type of pathology in the renal unit
Figure 3. (A) USG of the diseased kidney started from medial aspect and advancing laterally; (B) local anesthetic injected at the site selected for percutaneous access directing along the intended line of tract placement (puncture guide – dotted line in incet); (C) skin incision is made using No. 11 surgical scalpel; (D) a 15-cm, diamond-tipped, 18-gauge two-part trocar needle is engaged in needle attachment connected with the USG probe. USG: ultrasound guidance
Step 4: puncture technique
The 5 mL LA in form of 2% lignocaine is injected at the site selected for percutaneous access and directed in deeper planes along the intended line of tract placement guided by puncture guide
Figure 4. (A) Tip of the needle is engaged first through the skin incision site; (B) as the needle is advanced its tip is seen along the dotted line; (C) egress of urine after removing needle stellate; (D) dye study for calyceal delineation as seen on fluoroscopy
Step 5: guide wire insertion
Once position of needle is ensured, guide wire (0.038-inch diameter) is introduced through the needle under fluoroscopy guidance, trying to negotiate it into the ureter
Figure 5. (A) Guide wire is introduced and parked into ureter under fluoroscopy; (B) tract dialatation using single step fascial dilator (14 Fr) over the guide wire using rotatory screw movements of hands; (C) dilator and guide wire should be in straight line and any guide wire kinking or buckling of kidney is avoided; (D) Malecot in place with its opened flower end
Step 6: tract dialatation
With help of No. 11 surgical scalpel, tract is incised by sliding scalpel over needle until dorsolumber fascia is incised. Tract then is dilated up to 14 F using single step fascial dilator over the guide wire using rotatory screw movements of hands
Step 7: insertion of nephrostomy over guide wire
In a similar fashion and direction as used during tract dilatation nephrostomy tube is inserted with screwing movement of hands (avoid pushing) over the guide wire until it reaches well into the pelvis. We generally prefer to use 14 F Malecot catheter as nephrostomy tube, as it is self-retaining and less chances to get blocked due to its large diameter even in infective conditions like pyonephrosis. Once in place Malecot catheter inner occluder is opened and flower rotation should be appreciated under fluoroscopy guidance
Post procedure care
Vitals should be recorded every half hourly for first 6 h post procedure. As the most important indication for nephrostomy placement is obstructive uropathy, so after decompression diuresis is expected in these patients mandating close monitoring of urine output and electrolytes. Bed rest should be advised for around 4 h with recommencement of the preprocedural diet. If sepsis is suspected, a broad spectrum injectable antibiotic is started round the clock. Nephrostomy tube should be checked for its patency periodically and if blocked can be gently washed with diluted 5 mL betadine/antibiotic solution.
Fluoroscopy guided access
A complete opacification of the system is done using the chiba needle and thereafter access is gained in the appropriate calyx<6>.
MDCT guided access
In cases where the collecting system is complicated with difficult anatomy MDCT guided access is valuable with added advantage of delineating abnormal anatomy with respect to surrounding viscera and access site. Main limitations are its availability and radiation exposure<7>.
Advantages of ultrasound guided technique
(1) Reduces radiation exposure both for operating staffs and patients; (2) decreases need for contrast media; (3) decreases chances of major adjacent viscera organ or major vessel (color doppler) injury; (4) can be performed in supine position; (5) can be done safely in pregnant, pediatric patients; (6) method of choice in transplant kidney and ectopic kidney (reduces chances of bowel injury); and (7) overcomes the problem of unsuccessful retrograde ureteral catheterization that is required for contrast media injection in fluoroscopic guidance.
Disadvantages of ultrasound guided technique
Technically challenging for novice as well in case of mild or no hydronephrosis.
Tips and tricks of successful ultrasound guided puncture
(1) Proper positioning and surface marking as described; (2) correct identification of posterior calyx; (3) use puncture guide during puncture of desired calyx; (4) use diamond tipped needle instead of beveled tipped needle during puncture; (5) in case of inadequate dilatation of pelvicalyceal system diuretic can be given preoperatively; (6) during puncture one should appreciate full course of needle along the puncture guide; (7) once calyx is punctured and dye is instilled, the target calyx should be opacified first followed by pelvis and other calyx; (8) placement of guidewire through the target calyx into ureter or upper calyx; and (9) always perform repeat ultrasound at end of procedure to see for any residual hydronephrosis which may require another PCN placement.
(1) Hematuria: virtually every patient have some amount of transient hematuria but only 1-3% of those patients require transfusion, surgery, or embolization. If noted at the time of nephrostomy itself, can be controlled by applying tamponade over the nephrostomy tract<8>; (2) pain: this is also one of the common complications, can be controlled by oral/IV analgesics; (3) sepsis: PCN insertion in pyonephrotic kidneys can result in severe bacteremia and sepsis; (4) injury to adjacent organs: pneumothorax and colonic injury are rare but are known complication especially in supracoastal punctures; (5) extravasation of urine; (6) catheter dislodgement; and (7) inability to remove nephrostomy tube due to crystallization.
USG guided technique of PCN placement is safe, effective and easily reproducible if done with correct technique though it requires some degree of learning curve to overcome to become competent in this technique.
Study conception and design, drafting of the manuscript: A. Jairath
Drafting of the manuscript, critical revision: A. Ganpule
Critical revision: M. Desai
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
Cite This Article
JairathA, GanpuleA, DesaiM. Percutaneous nephrostomy step by step. Mini-invasive Surg2017;1:180-85 http://dx.doi.org/10.20517/2574-1225.2017.24