IR and Palliation Flashcards
Antegrade pyelography
- Renal pelvs punctured under US guidance, radiographic contrast medium injected to demonstrate anatomy and level of obstruction
- Urine can also be aspirated for microbiology/cytology
Percutaneous nephrostomy
- Insertion of a pigtail catheter into the collecting system
- External bag for short term drainage, otherwise internal stenting generally preferred
Biliary drainage
ERCP with stent
- stents inserted endoscopically, if at the low CBD
- Failure rate 30-40% plastic stents, 10-15% with metallic
- Higher rates of cholangitis with plastic stents
- If stents occlude, can be replaced (plastic) or have patency restored (metallic)
- Generally worthwhile for QOL improvement unless life expectency is very short
Percutaneous transhepatic biliary drainage
- Used if level of biliary obstruction is high (proximal to common bile duct) or there is distorted anatomy (prev surgery, local tumour)
- Also second line if ERCP fails
Thoracentesis
- Indicated at first presentation of a pleural effusion for diagnosis and therapeutic purposes
- Typically done with US
- Fluid re-accumulates in almost all patients, at which point decision is for pleurodesis vs a tunneled pleural catheter
Tunnelled pleural catheter
- Useful for patients who are ineligible for chemical pleurodesis or those who fail
- Soft catheter with polyester cuff to promote fibrosis to the subcutaneous tissue
- Drainage every other day
- Spontaneous pleurodesis occurs in up to 70% of patients
Chemical pleurodesis
- Ultrasound guided insertion of a tube thoracostomy
- Infusion of sclerosing agent (doxycycline, talc, bleomycin)
- May be painful for some patients
- Tunnelled pleural catheters now preferred in some centres
Indwelling pleural catheter
- Alternative to repeated paracentesis
- Use of tunnelled drain catheter with complication rate similar to that for large volume paracentesis, with drainage facilitated at home
Esophageal stents
- Self-expanding metal stents commonly used for dysphagia
- Placement can be done with fluoroscopy or endoscopy
- Low complication rate
- Covered metallic stents also useful for malignant esophageal fistulas to provide a seal, allow normal PO intake, and prevent thoracic sepsis/malnutrition
Gastroduodenal stents
- Nonsurgical alternative to treating GOO, particularly in patients who may be too frail for a surgical intervention
- Most appropriate for patients with a lifespan of 2-6 months
- Goal is for resumption of PO intake without obstructive symptoms and improved QOL
- Less likely to be successful when obstruction is due to peritoneal carcinomatosis
- May also be a temporising measure to allow stabilization of the patient prior to definitive surgery
- Note that covered stents are more likely to result in perforation - use only uncovered
Colorectal stents
- Self expanding metal stents
Indications:
- Palliation of surgically incurable colorectal cancer
- Emergent bridge to surgery, allowing for optimization and pre op staging
- Management of some patients with extracolonic pelvic tumours (e.g. ovarian ca)
Contraindications:
- Systemic toxicity (e.g. colonic ischemia)
- Intra abdominal abscess
- Persistent coagulopathy despite treatment
- Treatment with bevacizumab (high perforation rates)
**Avoid in distal rectal lesions (within 5 cm of anal verge) as a stent can induce pain, tenesmus, and rectal bleeding - but may allow patients to avoid an ostomy and some patients may wish to try it
Tracheobronchial stents
- Self expanding metallic stent for malignant airway obstruction
- Under general anesthesia, with IR and bronchoscopist
- Bronchoscopy to visualise stricture, marked with a radio-opaque marker, then dilatation under fluoroscopic guidance followed by insertion of a SEMS
Goal
- Symptomatic improvement
- Prevent collapse or infection/abscess beyond an obstruction lesion
**Consider a plastic covered metallic stent for a trachoesophageal fistula where esophageal stent is not feasible
Intravenous thrombolysis for SVC syndrome
- Superior venocavography to visualise site and extent of obstruction
- Can also be used for IVC obstruction
- Simple procedure that can improve WOL
Procedure:
- General anesthetic and selective thrombolysis if there is extensive thrombosis
- Percutaneous transfemoral dilatation of the narrowed SVC, followed by insertion of a self expandable metallic stent
- If tumour is compromising the trachea, airway stent can be placed during procedure as well
Insertion of an IVC filter
Indications
- VTE with absolute contraindication to therapeutic anticoags (ICH, severe active bleeding, recent brain/eye/spinal cord surgery, pregnancy, malignant hypertension), complications of coags, or failure of anticoag where there is acute proximal venous thrombosis
Controversy
- Retrospective study concluded higher 30 day mortality with ICV filter placement
Percutaneous gastrostomy
- Useful when patients are receiving feeds and patients wishes to avoid NG tubes or will require feeds long term
- Placed under fluoroscopy or endoscopic guidance and local anesthesia
Gastrostomy tubes preferred, but gastro-jejunostomy tubes are preferable if there is GOO or GERD
Extraction of ‘lost’ indwelling venous cannulas or catheters
- Equipment may break or dislodge with the catheter (or part thereof) ‘lost’ in the venous system
- Must be retrieved so that they do not perforate vascular structures, cause dysrhythmias, or cause infection
Technique
- Typically lodge in the right side of the heart or pulmonary arteries
- Typically removed with fluoroscopic guidance
Palliative embolization
- Used to control pain, hemorrhage, and hormone production while also reducing tumour bulk
- In some cases, embolization of tumours may improve survival
- Includes ‘TACE’ - transcatheter arterial chemo-embolization’ (cytotoxic agents mixed with embolic materials), used with HCC
- Requires attention to pre-medication (antibiotics to prevent infection, blockade for hormonal tumours, etc.)
Post-embolization syndrome
- Discomfort, pain, fever, and elevated WBC for a few days following embolization of large tumour masses
- Typically due to the presence of necrotic tissue
- Sustained pyrexia is concerning for abscess formation (get blood cultures and US or CT to image)
RFA of HCC/hepatic mets
- Alternating current to induce ionic agitation, frictional heat production within the tissues and cell death
- Generally tolerated well
Complications
- Transient elevation of liver enzymes
- Abscess formation
- Intraperitoneal hemorrhage
Monitoring
- CT to gauge remaining viable tumour (US not very helpful as fibrotic and neoplastic lesions look similar)
- Follow AFP or CEA for trend
RFA of renal masses
- Useful for patients who are poor candidates (though nephrectomy - complete or partial - is standard of care)
- May also be helpful for persistent hematuria
- Preserves kidney function
- Centrally located masses in the kidney harder to treat
Complications:
- Hemorrhage
- Urinoma
- Abscess
- Paresthesias
- Transient hematuria
- Pain
RFA of adrenal tumours
- RFA may improve survival in patients who are not able to undergo surgical excision
- Ensure appropriate endocrine evaluation is complete with appropriate blockade prior to treatment
RFA of lung tumours
- Useful when palliation for pain or a mass lesion is needed or for patients with a small primary NSCLC who are not operative candidates due to comorbidities
Complications:
- Pneumothorax (10-20%)
- Bleeding
- Fistula
- Hemoptysis
- Effusions
- Fever
- Infection
- Pain
RFA of soft tissue mets
- May be useful for painful soft tissue tumours resistant to conventional rads or pharm therapies
- Short term local control
