Central venous Catheters
Central venous catheter insertion is a common and essential procedure for critically ill patients. It involves various techniques and devices that serve multiple purposes, including total parenteral nutrition, dialysis, medication administration, plasmapheresis, and hemodynamic monitoring. These catheters can also facilitate complex interventions like transvenous pacemaker placement. Depending on the specific need, different devices are used to achieve central venous access. These catheters not only enable the delivery of vasoactive medications and venous irritants but also support dialysis, plasmapheresis, and the insertion of additional devices for complex procedures. This review emphasizes the procedure of central venous catheter insertion and underscores the collaborative efforts of the interprofessional team in managing patients who undergo this process.
Significant anatomical variations of SVC:
The Superior Vena Cava (SVC) is formed by the confluence of the right and left brachiocephalic veins. It runs along the right middle mediastinum, draining into the right atrium and coursing next to the trachea and ascending aorta. The average length of the SVC is 7.1 cm ± 1.4, with a maximum diameter of 2.1 cm ± 0.7 in adults. An SVC area less than 1.07 cm² indicating potential obstruction or compression.
The azygos vein is a significant tributary that travels along the right anterior thoracic vertebrae, extending to the carina and then curving over the right tracheobronchial angle before draining into the distal SVC. Besides the azygos vein, there are only a few major SVC tributaries. Nonetheless, some mediastinal, esophageal, and pericardial veins may directly drain into the SVC. Collateral venous pathways become identifiable in cases of SVC obstruction and include the azygos–hemiazygos–accessory hemiazygos system, mediastinal venous plexus, diaphragmatic venous plexus, lateral thoracic and superficial thoracoabdominal venous plexus, and abdominal venous collaterals.
| Congenital |
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| Persistent Left SVC | 1. Most common thoracic venous anomaly 2. Right SVC can be normal, small, without anterior communicating vein (bridging vein) or absent (if absent then look for cardiac anomalies like ASD, VSD, TOF, Bicuspid aortic valve, Aortic coarctation, Mitral atresia or cor triatriatum) 3. Dilated coronary sinus should indicate for persistent left SVC 4. Raghib Syndrome (synonym - coronary sinus atrial septal defect) - Persistent left SVC accompanied by abnormal communication with left atrium at level of left atrial appendage or coronary sinus (creating small right to left shunt). Incidentally detected, asymptomatic. - Rarely cause systemic embolus leading to stroke or brain abscess. Management is done by attaching the bridging vein (adequate size) to right side and left SVC ligation or by reimplanting left SVC to right side (bridging vein is of inadequate size)9+ | Differentials for dilated coronary sinus: 1. Right ventricular failure 2. Right arterial hypertension 3. Severe Pulmonary hypertension 4. Tricuspid regurgitation 5. Coronary AV fistula 6. Cardiac Tamponade 7. Persistent left SVC Patent left SVC causes difficulty in placement of (because of narrow opening of coronary sinus into right atrium) 1. Pacemaker 2. Swan-Ganz catheter 3. Implantable cardioverter-defibrillator leads |
| Right upper lobe partial anomalous pulmonary venous return (PAPVR) | 1. Associated ASD 2. Ct angio - provides anatomical details 3. Phase contrast MR imaging provides information regarding degree of left to right shunt and also helps in flow quantifiaction. | |
| SVC aneurysm | 1. Occurs due to congenital weakness in SVC wall or absence of longitudinal muscle layer in tunica adventitia 2. Saccular shape - surgical resection is advised to avoid complications like rupture, thrombus formation with or without pulmonary thromboembolism and compression of adjacent structures. 3. Fusiform shape - conservative management should be considered | |
| Acquired | ||
| SVC stricture | 1. Severe narrowing leads to SVC syndrome (swelling upper extremities, neck and face) due to impaired venous return 2. Formation of extensive venous collaterals: - Grade Ia = Mild narrowing without collaterals - Grade Ib = Moderate narrowing without collaterals - Grade II = Obstructive above azygous arch - Grade III = Obstructive below azygous arch with azygous vein serving as partial collateral - Grade IV = Obstruction at azygous arch | Intrinsic Factors - Long standing Central venous cather (CVC) - intimal irritation and inflammation leading to intimal hyperplasia -Transvenous Pacemaker - Post-operative /Radiation effect Extrinsic Factor: - Compression from mediastinal mass - Malignancy - Fibrosing Mediastinitis (mediastinal fibrosis) - Lymphadenopathy - Aortic Aneurysm |
| Fibrin Sheath | 1. Homogenous matrix of cell and debris with variable amount of thrombus and endothelial cell collagen. 2. Act as partial block - acting as one way block | |
| Thrombus (Leads to SVC syndrome) | 1. Bland type 2. Tumor Thrombus (Better detection by MR imaging and FDG PET-CT) - Small and non small cell carcinoma lung carcinoma - Mediastinum origin (lymphoma/metastasis) - Pleural and Tracheal origin | 1. Intrathoracic malignancy 2. CVCs, 3. Pacemakers and 4. Prior radiation therapy |
| Primary Neoplasm | 1. SVC lipoma or extension of lipomatous hypertrophy of intraarterial septum 2. Primary SVC sarcoma or Leiomyosarcoma | Most common SVC malignancy is metastasis |
| Trauma | Fatal - Patient succumb shortly after injuries. | |
Vascular Access routes for CVC:
| Vascular access route | Benefits | Disadvantages |
|---|---|---|
| Internal jugular vein | 1. Easily palpable landmarks 2. Short straight course to SVC 3. Valveless 4. Carotid artery directly compressible if punctured | 1. Awkward neck positioning for patients 2. Accidental pneumothorax during insertion - low approach |
| Subclavian vein | More comfortable for patients than IJV | 1. Higher incidence of pneumothorax than IJV 2. Difficult to apply direct pressure if subclavian artery punctured |
| Femoral vein | Low complication rate | 1. Groin area subject to infection 2. Impairs patient mobility |
| External jugular vein | Low complication rate | 1. Venous valves may prevent smooth insertion 2. Tortuous course 3. Smaller vessel – large sheaths may tear vessel wall |
| Basilic and Cephalic | Low complication rate | 1. Increased risk of thrombosis and thrombophlebitis 2. Smaller vessels |
| Translumbar IVC | ||
| Transhepatic IVC |
PICC line insertion:
Understanding CVC:
| Indication | 1. Prevent venous wall damage of small peripheral veins 2. High venous flow needed - Dialysis 3. Monitoring central venous or pulmonary artery pressure |
| Non-tunneled catheters | 1. Central venous catheters 2. Swan-Ganz catheters (pulmonary artery catheter) 3. Shaldon-catheters (dialysis) and 4. PICC lines (peripherally inserted central catheter, usually through the basilic or cephalic veins) |
| Tunneled catheters | 1. Hickman or Broviac catheters 2. Demers catheters |
| Choice of Device | 1. Duration of the central venous access 2. Flow rates 3. Availability 4. Further planned therapies |
| Features | 1. Valves - allow heparin free flushing of catheter 2. Drug-coated device - Reduce infection and thrombosis rates 3. Cuffs (near proximal end) - intended for tissue ingrowth resulting in fixation of the catheter after approximately three to four weeks |
| Catheter tip placement | 1. Neonates - carina level 2. Hemodialysis catheters - catheter should enter the RA for better function 3. Recumbent patient - one vertebral body height distance below the carina |
| Duration | Non-tunneled catheter - 2 weeks PICC lines - up to 3 months Tunneled catheter - more than 3 months |
| Contraindication | 1. No absolute contraindication 2. Local infection or septicemia |
| Complications | 1. Air embolism - Aspiration due to negative venous pressure - Use half filled 2 ml syringe while initial puncture 2. Arterial puncture - Rare when USG guided puncture is taken, confirm venous location prior to introduction of dilators or sheath manual compression is usually sufficient. 3. Bleeding - Using local anesthetic with added vasoconstriction agents 4. Pneumothorax is a rare complication mostly seen in difficult access cases 5. Hemothorax 6. Thrombosis - Early and late (symptoms are arm pain and swelling) - Anticoagulation therapy, line removal 7. Catheter related blood stream infection - Isolation of same organism from catheter segment and blood stream drawn from peripheral vein with bloodstream - Antibiotic management and line removal 8. Catheter fracture 9. Catheter Migration - Snaring and removal 10. Catheter Dysfunction - Most commonly by fibrin sheath formation - Fibrin sheath removal |