فحوصات

• Percutaneous antegrade pyelography and nephrostomy

  Introduction of a drainage catheter into the collecting system of the kidney
• Indications for percutaneous antegrade pyelography and nephrostomy

  • Renal tract obstruction
  • Pyonephrosis
  • Prior to percutaneous nephrolithotomy
  • Ureteric or bladder fistulae: external drainage (i.e. urinary diversion may allow closure)
• Contraindications for percutaneous antegrade pyelography and nephrostomy


  • Uncontrolled bleeding diathesis
• Contrast medium


  As for percutaneous renal puncture
• Equipment for percutaneous antegrade pyelography and nephrostomy

  • Puncturing needle: coaxial needle/catheter set or sheathed 18G needle
  • Drainage catheter: at least 6-F pigtail with multiple side holes
  • Guidewires: conventional J-wire ± extra stiff wire
  • US and/or fluoroscopy—usually used in combination
• Patient preparation for percutaneous antegrade pyelography and nephrostomy

  • Fasting for 4 h
  • Premedication as required
  • Prophylactic antibiotic
• Technique for percutaneous antegrade pyelography and nephrostomy

  1. Patient position: Patient lies prone oblique with a foam pad or pillow under the abdomen to present the kidney optimally

  2. Identifying the collecting system prior to the definitive procedure: Freehand or with a biopsy needle attachment; US guidance is the most common method for localizing the kidney and guiding the initial needle puncture into the collecting system

  3. Site/plane of puncture: A point on the posterior axillary line is chosen below the twelfth rib. Having identified the mid/lower pole calyces with US or contrast, the plane of puncture is determined

  4. Techniques of puncture and catheterization: The skin and soft tissues are infiltrated with local anaesthetic using a spinal needle. Puncture may then be made using one of the following systems: An 18G sheathed needle, or Kellett needle, using the Seldinger technique for catheterization; Coaxial needle puncture systems using a 22/21G puncturing needle that takes a 0.018 guidewire; The trochar-cannula system, in which direct puncture of the collecting system is made with the drainage catheter already assembled over a trocar

  
• Antegrade pyelography


  1. Oblique and AP images are taken with gentle introduction of water-soluble contrast medium

  2. Semierect films may be necessary to encourage contrast medium down the ureters, to show the site and nature of obstruction

  3. Postnephrostomy studies are best performed after a delay of 1–2 days, to allow the patient to recover and be able to cooperate, blood clot to resolve and infected systems to be drained

  
• Aftercare for percutaneous antegrade pyelography and nephrostomy

  • Bed rest for 4 h
  • Pulse, blood pressure and temperature half-hourly for 6 h
  • Analgesia
  • Urine samples sent for culture and sensitivity
• Complications of percutaneous antegrade pyelography and nephrostomy

  • Septicaemia
  • Haemorrhage
  • Perforation of the collecting system with urine leak
  • Unsuccessful drainage
  • Injury to adjacent organs such as lung, pleura, spleen or colon
  • Later catheter dislodgement
• Percutaneous nephrolithotomy

  Removal of renal calculi through a nephrostomy track
• Indications for percutaneous nephrolithotomy


  • Removal of renal calculi
  • Disintegration of large renal calculi
• Contraindications for percutaneous nephrolithotomy


  • Uncontrolled bleeding diathesis
• Equipment for percutaneous nephrolithotomy

  • Puncturing needle (18G): Kellett (15–20 cm length) or equivalent
  • Guidewires, including hydrophilic and superstiff
  • Track dilating equipment; Teflon dilators (from 7-F to 30-F), metal coaxial dilators or a special angioplasty-type balloon catheter
  • US machine
  • Fluoroscopy facilities with rotating C arm, if possible
• Patient preparation for percutaneous nephrolithotomy

  • Full discussion between radiologist/urologist concerning indications and so on
  • Imaging (IVU, CT KUB, CTU) to demonstrate position of calculus and relationship to calyces
  • General anaesthetic
  • Coagulation screen
  • Two units of blood cross matched
  • Antibiotic cover
  • Premedication
  • Bladder catheterization, as large volumes of irrigation fluid will pass down the ureter during a prolonged procedure
• Technique for percutaneous nephrolithotomy

  1. Preprocedure planning may include a CT KUB and CTU to localize stones and to choose most appropriate access

  2. Patient position: As for a percutaneous nephrostomy, usually prone

  3. Methods of opacification of the collecting system: Retrograde ureteric catheterization for demonstration and distension of the collecting system may be achieved, Intravenous excretion urography, Antegrade pyelography

  4. Puncture of the collecting system: A lower pole posterior calyx is ideally chosen if the calculus is situated in the renal pelvis. Otherwise the calyx in which the calculus is situated is usually punctured

  5. Dilatation: This is carried out under general anaesthesia. It is performed using Teflon dilators from 7-F to 30-F, which are introduced over the guidewire. Alternatively, metal coaxial dilators or a special angioplasty balloon (10 cm long) are used

  6. Removal/disintegration: Removal of calculi of less than 1 cm is possible using a nephroscope and forceps. Larger calculi must be disintegrated using an ultrasonic or electrohydraulic disintegrator

  
• Aftercare for percutaneous nephrolithotomy

  • A large bore soft nonlocking straight nephrostomy tube (sutured) is left in for 24 h following the procedure
  • Patient care is usually determined by the anaesthetist/urologist
  • Plain radiograph of the renal area to ensure that all calculi/ fragments have been removed
• Complications of percutaneous nephrolithotomy

  • Immediate: Failure of access, dilatation or removal, Perforation of the renal pelvis on dilatation, Inadvertent access to renal vein and IVC, Haemorrhage. Less than 3% of procedures should require transfusion. Rarely, balloon tamponade of the tract or embolization may be required, Damage to surrounding structures (i.e. diaphragm, colon, spleen, liver and lung), Problems related to the irrigating fluid
  • Delayed: Pseudoaneurysm of an intrarenal artery, Arteriovenous fistula
• Renal arteriography

  Radiographic imaging of the renal arteries
• Indications for renal arteriography

  • Renal artery stenosis prior to angioplasty or stent placement. Diagnostic arteriography has been replaced generally by MR or CT angiography (MRA or CTA)
  • Assessment of living related renal transplant donors—replaced generally by MRA or CTA
  • Embolization of vascular renal tumour prior to surgery
  • Haematuria particularly following trauma, including biopsy. This may precede embolization
  • Prior to prophylactic embolization of an angiomyolipoma (AML) or therapeutic embolization of a bleeding AML
• Contrast medium for renal arteriography

  • Flush aortic: LOCM 300/320 mg I mL−1, 45 mL at 15 mL s−1
  • Selective renal artery injection: LOCM 300 mg I mL−1, 10 mL at 5 mL s−1, or by hand injection
• Equipment for renal arteriography

  • Digital fluoroscopy unit
  • Pump injector
  • Catheters: Flush aortic injection—pigtail 4-F, Selective injection—Sidewinder or Cobra catheter

  
• Technique for renal arteriography

  Femoral artery puncture: For flush aortography, a pigtail catheter is placed proximal to the renal vessels (i.e. approx. T12) and AP, and oblique runs are performed. Selective catheterization as required is used with appropriate catheters for optimal demonstration of intrarenal vessels, and prior to interventional procedures