Interventional Radiology PDF

Joint injection Aspiration / Drainage Vertebroplasty By the end of lecture students should be: ▀Summarize the basic information concerning aspiration / drainage and joint injection procedure ▀ Develop the ability of performance aspiration / drainage and joint...

Joint injection Aspiration / Drainage Vertebroplasty By the end of lecture students should be: ▀Summarize the basic information concerning aspiration / drainage and joint injection procedure ▀ Develop the ability of performance aspiration / drainage and joint injection procedure ▀ Illustrate the purpose, indication, and necessary patient preparation for each type of aspiration / drainage and joint injection procedure  Diagnostic aspiration Diagnostic aspiration tends to be used when the nature of the collection is unclear or when there is a small collection that is very difficult to drain. A diagnostic aspirate gives bacterial sensitivity and allegedly reduces the abscess wall tension, which helps antibiotic penetration. Always undertake aspiration under sterile conditions and avoid traversing bowel as there is a real opportunity to inoculate and infect a collection. If you use a 20G needle and cannot aspirate then a further puncture is usually needed. If possible, plan the aspiration so that the route is suitable for drainage as if you aspirate pus that is usually the next step  Drainage Drainage is all about getting gravity on your side, so plan the drainage route so that the shortest access is achieved that will result in a drain in a dependent position and preferably with the drain hub below the level of the collection. Think about the content of the collection. Ultrasound offers the most useful assessment of the viscosity of the collection and the presence of loculi and septa. If the collection is loculated, then target the largest locule first. Look for the following features, which will influence the type and number of drains required: Anechoic collection – probably clear fluid, e.g. urinoma Few scattered echoes – turbid fluid, e.g. thin pus Extensive or swirling echoes – thick fluid, e.g. viscous pus Diffuse echoes with gas – organized abscess or phlegmon.  Drainage catheter Use a 6–8Fr catheter for clear fluid, 8–10Fr catheter for thin pus, 10–12Fr catheter for thick pus and a 12–22Fr drain for collections containing debris.  Procedure The precise technique depends on the type of catheter that has been chosen. Prepare and anaesthetize the skin and the desired puncture site. Make a sufficiently large skin incision to allow passage of the drainage catheter. Pass a needle into the collection, using imaging guidance. Most operators will use a two-step procedure; fluoroscopy is recommended though the skilled operator can do this under ultrasound alone  A supportive guidewire is passed through the puncture needle into the collection. The needle is removed over the wire and the track is dilated using fascial dilators to 1–2Fr larger than the drainage catheter. Fix the wire securely to ensure that it does not kink and that you do not lose wire position during catheter exchanges. The catheter stiffener assembly is then passed over the wire into the collection. When you reach either a significant bend or the collection, detach the stiffener, hold the stiffener and the wire fixed in position, and slide the catheter forward over the guidewire Securely attach the catheter to the patient. There are several ways to do this: Suturing the catheter to the skin Using adhesive anchor systems Using adhesive tape – only secure with waterproof tape. Make sure that the final position will be practical and as comfortable as possible for the patient.  Specific sites Subphrenic abscess Subphrenic collections are usually postoperative. They are inconveniently located, as getting below the pleural reflection can be a challenge. The best approach is with a combination of ultrasound and fluoroscopy and it might need a bit of mental triangulation to determine the upward path for the needle. Some centres will accept an intercostal approach on the premise that the pleural surface will be adherent and empyema is unlikely. While this is an option, we would be cautious about this approach for all patients. Remember to add empyema to the potential complications during consent, regardless of whether you deliberately go through the pleural surface or not. Subphrenic abscess  Upper abdominal solid organ abscesses Liver, renal and splenic abscesses can all be drained percutaneously with reported success rates usually around 90%. Drainage is usually performed under ultrasound guidance and less commonly CT. Peripancreatic abscesses, pseudocysts and phlegmons are common complications of pancreatitis. Infected collections often require drainage Risks are increased with more vascular organs like the spleen and there is a tendency to use smaller catheters.  Liver abscess Renal abscess Splenic abscess  Pericolic abscess These are usually secondary to diverticular disease, periappendiceal or postoperative collections. The aim is often as a bridge to a surgical procedure, however some centres will Imaging guidance is always by CT and care should be taken to avoid puncturing adjacent loops. Further follow-up imaging is usually with CT.  Pelvic collections The commonest difficulty in pelvic biopsy or drainage is identifying a route that does not transgress bowel or bladder. Gravity causes pus to collect in the prerectal space; this is difficult to access from an anterior approach. Alternative options include transrectal, transvaginal and transgluteal approaches. The commonest approach in most centres is transgluteal drainage.  The posterior transgluteal route traverses the sacrosciatic notch and uses CT guidance. The patient is scanned in the prone position and the approach is planned in the conventional fashion. Remember that the sciatic nerve and gluteal vessels pass through the anterior portion of the notch. To avoid them, the tract should pass as close to the sacrum as possible. Burrowing through this much muscle can be difficult and may be uncomfortable for the patient both during and after the procedure. Peri-catheter inflammation can cause sciatica even when the catheter is appropriately placed.  Ultrasound-guided transrectal and transvaginal drainage are readily performed and well tolerated. Although these approaches are unfamiliar, the basic principles of biopsy and drainage apply. These routes offer a direct approach to posterior collections, with the advantage of draining well in the supine position. Most suitable probes have needle guides. Use sterile covers over the probe and guide. The collection is punctured under direct visualization. As always, aspirate some fluid; if it is purulent, formal drainage is performed; if not, the collection is aspirated to dryness. Catheter fixation is difficult and self-retaining catheters are preferred. The catheter can be taped to the patient’s thigh and drained into a leg bag. Transgluteal route for drainage of a presacral abscess (arrows). The catheter (arrowheads) passes close to the sacrum to avoid the sciatic nerve and gluteal vessels that lie anteriorly Transrectal procedures cause surprisingly little discomfort but this is a ‘dirty’ route. A cleansing enema is recommended to remove any faecal residue and antibiotic prophylaxis must be given. Contamination of the collection with faecal organisms is a potential pitfall but is thought not to occur because of the positive intra-abdominal pressure during defaecation. The patient is scanned in the lateral decubitus or lithotomy position. Drains up to 12Fr can be used. Catheter displacement during defaecation is common even with self-retaining catheters.  The transvaginal approach is performed with the patient in the lithotomy position. Sedation is recommended as the procedure tends to be uncomfortable and the vaginal wall can be difficult to traverse. The vagina and perineum are cleaned with povidone iodine solution. Catheters up to 12Fr can be used but require employing serial fascial dilators over a stiff guidewire.  Pancreas Peripancreatic abscesses, pseudocysts and phlegmons are common complications of pancreatitis. Infected collections often require drainage. The management of complex pancreatitis is best left to a specialist team but the following guidelines are generally applicable. Collections in the lesser sac can usually be approached anteriorly through the transverse mesocolon between the stomach and transverse colon. Collections in the left paracolic gutter are more difficult to approach and are best done with CT guidance to avoid colonic puncture. Loculated collections may require several drains. As always, frequent review is mandatory. This often entails serial CT scanning. Large pseudocysts, which continue to drain, can be treated by cyst gastrostomy. EXAMPLE OF DRAINS Intercostal Chest Drains  Intercostal Chest Drains These are used to remove fluid or air within the pleural space Main indications for insertion – Pneumothorax Tension Simple pneumothorax unresponsive to aspiration Pnemothorax in a patient with chronic lung disease – Drainage of pleural fluid Pleural effusion Haemothorax  Optimum position of drain This depends on why the drain is being inserted: – Pneumothorax Towards lung apex (superiorly) – Pleural fluid drainage Towards cardiophrenic border (inferiorly)  Bilateral chest drains This patient has bilateral chest drains, inserted following pneumothoraces secondary to rib fractures. Note surgical emphysema. Both drains lie towards the apex, but the left drain is coiled and should be withdrawn a little. The pneumothoraces are not visible on this film.  Problems with Chest Drains These mostly occur with drain placement – Pain, damage to neurovascular bundle – Trauma to liver, spleen, lung – Drainage ports These must lie within the chest or there is a risk of surgical emphysema and drain failure Drainage hole correctly sited within chest  Complications Complications related to drainage are relatively rare but no technique or operator can completely avoid them. Acute sepsis: Always give appropriate broad-spectrum antibiotics prior to drainage. It is not surprising that sepsis occurs as some bacteraemia during drainage is almost bound to occur. Prompt resuscitation is essential with second-line antibiotics/IV fluids/oxygen and blood cultures. Liaison with the clinical team is essential, as they will need to continue resuscitation and consider moving to a more supportive environment  Bleeding: If you notice bleeding from the tract during dilatation, the best tactic is to ensure you tamponade the tract by inserting the drain. Most tract bleeding is venous and will settle quickly. Monitor pulse and blood pressure, and if there are any adverse features get a CT to plan further therapy such as arterial embolization.  Joint injection -Vertebroplasty DEFINITION  Vertebroplasty, a nonsurgical treatment performed by interventional radiologists using imaging guidance, stabilize the collapsed vertebra with the injection of medical-grade bone cement into the spine. This reduces pain, and can prevent further collapse of the vertebra, thereby preventing the height loss and spine curvature commonly seen as a result of osteoporosis. Vertebroplasty dramatically improves back pain within hours of the procedure, and has a low complication rate.  Vertebroplasty is a pain treatment for vertebral compression fractures that fail to respond to conventional medical therapy.  The Uses  Vertebroplasty are used to treat pain caused by vertebral compression fractures in the spine.  Typically, Vertebroplasty is recommended after simpler treatment, such as bed rest, a back brace or pain medication, have been ineffective, or once medications have begun to cause other problems, such as Stomach ulcers  Vertebroplasty can be performed immediately in patients who have severe pain requiring hospitalization or conditions that limit bed rest and medications.  Vertebroplasty is also performed on patients who:  Are too elderly or fail to tolerate open spinal surgery, or who have bones too weak for surgical spinal repair  Have vertebral damage due to a malignant tumor  Are younger and have osteoporosis caused by long-term steroid treatment or a metabolic disorder.  Indications for Vertebroplasty ▪ Painful osteoporotic fractures less than one year old ▪ Pain refractory to traditional medical therapy  No long-term relief with analgesics (and/or side effects to dosage includes excessive drowsiness, confusion or constipation)  Pain negatively impacting mobility and activities of daily living.  Worsens with weight bearing  Relieved with rest or when recumbent ▪ Painful fracture related to benign or malignant tumor (metastatic disease, hemangiomas) ▪ Patient with multiple compression fractures for whom further collapse would result in compromised pulmonary or GI function Indications for Vertebral Augmentation ▪ Unstable compression fracture with movement at the wedge deformity ▪ Chronic traumatic fracture with non-union of the fracture fragments ▪ Pain from fracture localized to site of the fracture (or 1-2 levels away) – tender on palpation ▪ Often band-like radiation of pain ▪ Radiographic evidence of compression fracture ▪ Negative CT/MRI for HNP, retropulsed fragment. ▪ (Herniated nucleus pulposus) Unstable wedge fracture The preparation  On the day of the procedure, pt should be able to take usual medications with sips of water or clear liquid up to three hours before the procedure. Pt should avoid drinking orange juice, cream and milk.  In most cases, pt may take usual medications, especially blood pressure medications. These may be taken with some water in the morning before the procedure.  Pt does not eat anything for several hours(4-6) before the procedure.  The pt given bone-strengthening medication during treatment  In Vertebroplasty procedures, X- ray equipment, a hollow needle or tube called a trocar, Orthopedic cement, barium powder and a solvent are used.  The orthopedic cement includes an ingredient called polymethylmethacrylate (PMMA)  Other equipment that may be used during the procedure includes an intravenous line (IV) and equipment that monitors heart beat and blood pressure.  Procedure:  Vertebroplasty involves injecting a special cement mixture into the small holes in weakened vertebrae to strengthen the spinal bones making them less likely to fracture again and providing pain relief.  Using image-guidance, a hollow needle called a trocar is passed through the skin into the spinal bone and a cement mixture is then injected into the vertebra.  The performance:  Image-guided, minimally invasive procedures such as Vertebroplasty are most often performed by a specially trained interventional radiologist in an interventional radiology suite or occasionally in the operating room.  This procedure is often done on an outpatient basis.  Pt positioned lying face down for the procedure.  And connected to monitors that track pt heart rate, blood pressure and pulse during the procedure.  A nurse or technologist will insert an intravenous (IV) line into a vein in pt hand or arm so that sedative medication can be given intravenously. And also receive general anesthesia.  Pt given medications to help prevent nausea and pain, and antibiotics to help prevent infection.  The area where the hollow needle will be inserted will be shaved, sterilized and covered with a surgical drape.  A local anesthetic will be injected into the muscles near the site of the fracture.  A very small open is made in the skin at the site.  Using x-ray guidance, a hollow needle called a trocar is passed through the spinal muscles until its tip is precisely positioned within the fractured vertebra.  In Vertebroplasty, the orthopedic cement is then injected. Medical- grade cement hardens quickly, typically within 20 minutes.  On occasion, a CT scan may be performed at the end of the procedure to check the distribution of the cement.  The trocar is then removed.  Pressure will be applied to stop any bleeding and the opening in the skin is covered with a bandage.  And recovery room for an hour following the intravenous line will be removed.  This procedure is usually completed within one hour. It may take longer, especially if more than one vertebra is being treated.  Lobel: Start to finish 1. Review MRI with STIR, pick approach 2. Get patient in good position for both them and you 3. Scout fluoro from T6 to sacrum, match fractures 4. Using MRI knowledge, pick trajectory 5. Wide prep, wide drape, lots of local 6. Get needle perfect. Finish where you start!!! 7. Pull back, balloon, cement, 360, no straws. (Short Tau Inversion Recovery)  Transpedicular Approach - Troubleshooting ▪ Trajectory too steep ▪ Final placement will be anterior and on near side Needle Positioning & Placement ◼ Accurate needle placement is critical for effective cement injection and to reduce risk of complication ◼ Use of high-quality fluoroscopy imaging equipment is critical to get accurate needle placement ◼ Transpedicular approach is safest; often bilaterally ◼ 11 gauge needle for lumbar and lower thoracic spine; 13 gauge for mid to upper thoracic  Benefits:  Vertebroplasty can increase a patient's functional abilities, allow a return to the previous level of activity without any form of physical therapy or rehabilitation and prevent further vertebral collapse.  These procedures are usually successful at alleviating the pain caused by a vertebral compression fracture; many patients feel significant relief almost immediately. Many patients become symptom-free. Benefits:  Following Vertebroplasty, about 75 percent of patients regain lost mobility and become more active, which helps combat osteoporosis. After the procedure, patients who had been immobile can get out of bed, reducing their risk of pneumonia. Increased activity builds more muscle strength, further encouraging mobility.  Usually, Vertebroplasty is safe and effective procedures.  No surgical incision is needed—only a small nick in the skin that does not have to be stitched closed  Risk  Any procedure where the skin is penetrated carries a risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in 1,000.  A small amount of orthopedic cement can leak out of the vertebral body. This does not usually cause a serious problem, unless the leakage moves into a potentially dangerous location such as the spinal canal.  Other possible complications include infection, bleeding, increased back pain and neurological symptoms such as numbness or tingling. Paralysis is extremely rare.  There is a risk of allergic reaction to the contrast material used for intraosseous venography.  The limitation  Vertebroplasty is not:  Used for herniated disk or arthritic back pain.  generally recommended for otherwise healthy younger patients, mostly because there is limited experience with cement in a vertebral body for longer time periods.  a preventive treatment to help patients with osteoporosis avoid future fractures. It is used only to repair a known, non-healing compression fracture. The limitation  used to correct an osteoporosis-induced curvature of the spine, but it may keep the curvature from worsening.  ideal for someone with severe emphysema or other lung disease because it may be difficult for such individuals to lie facedown for one to two hours Vertebroplasty requires. Special accommodations may be made for patients with these conditions.  for patients with a healed vertebral fracture.  Complications:  The complication rate associated with percutaneous Vertebroplasty is 1 to 3 percent for treatment of osteoporotic fractures and 7 to 10 percent for treatment of malignant neoplasms. The majority of complications are transient and minor, and they include the following: Hemorrhage;  Rib or vertebral posterior element fracture;  Transient fever and worsening of pain for several hours following the procedure caused by the heat generated by cement polymerization; Complications:  Nerve root irritation;  Cement embolization to the lungs via the paravertebral venous plexus;  Pneumothorax for thoracic lesions; and infection.  Permanent complications, including those requiring decompressive surgery to remove extruded cement or repair a fractured pedicle, occur at a rate of less than 1 percent. CT Scan A post injection CT image shows the cement filling the fractured vertebral body MRI A T1-weighted midsagittal magnetic resonance imaging scan showing a compression fracture at T12 that has normal bone marrow signal and is not acute (arrow). A second compression at L2 has abnormal bone marrow signal indicating an acute fracture (arrow).  Radiographic evaluation of age of fracture  Plain films  MRI Low signal T1 High signal T2 Best indicator of age is the history.