Complications related to vascular access are most common and most dreaded ones during percutaneous interventions. It increases both morbidity and mortality related to them. Obtaining an appropriate vascular access is the basis of a successful procedure. If proposed interventional anatomy is available then decision regarding access can be taken more appropriately. Once decided, a proper technique to gain vascular access helps to avoid complication.
FEMORAL ACCESS
Femoral access is still remains the preferred technique for cardiac catheterization at many centers. Although radial route has gained huge popularity because of patient convenience and less access site compilations, femoral route has an edge over it in complex procedures, it is technically easier, can use dedicated hardware which gives better support for the procedure. A simultaneous venous access can be used for temporary pacing, monitoring pulmonary artery pressures, or infusing fluids or medications. Femoral arterial access is still the most common access site for cardiac catheterization in USA.1 The technique of taking puncture is often underestimated but is a single most frequent cause of access site complications.2
ANATOMY OF FEMORAL ARTERY AND IDEAL LOCATION OF PUNCTURE
Femoral artery is entered through the femoral triangle, which in the groin is bounded superiorly by inguinal ligament, medially by adductor longus and laterally by sartorius muscle. Structures of femoral triangle from lateral to medial include femoral nerve, femoral sheath and its content which include femoral artery, femoral vein and deep inguinal lymph nodes and associated lymphatic vessels (Fig. 1).
An ideal “landing zone” of femoral artery puncture is defined by vascular entry above the femoral bifurcation and below the upper margin, which is several centimeters below the inferior excursion of the inferior epigastric artery3 (Fig. 2). Lower puncture can result in increased incidence of bleeding complications like hematoma and pseudoaneurysm because of lack of underlying bony structures to give adequate substrate for compression. Also the relatively smaller caliber of artery below the bifurcation makes it more prone for catheter related arterial occlusions.4 Whereas higher cannulation is also associated with increased risk of retroperitoneal hemorrhage because of lack of underlying bony structure for effective compression.5
PRACTICAL LANDMARKS FOR PUNCTURE
- Skin/Inguinal crease: It ideally signifies underlying inguinal ligament. An ideal arterial puncture (not skin puncture) should be 2–3 cm below the mid-point of the crease. However, in obese patients the ligament is much lower.
- Bony landmarks: Ideal point lies 2–3 cms below the mid-inguinal point which is the mid-point of a line drawn from anterior superior iliac spine and pubic tubercle.
- Maximal pulsation: Site of maximal pulsation may help in easy cannulation but it may often lead to a higher or lower puncture especially in obese patients.
- Fluoroscopic landmark: It is more appropriate method for cannulation of femoral artery and is used frequently in catheterization labs. In an AP view a metal clamp is used to mark the ideal point of arterial puncture. The ideal radiological location is 1 cm lateral to most medial aspect of femoral head, midway between its superior and inferior borders. The skin puncture is done 1–2 cm below that point at an angle of 30–45° from the skin. Target zone from the lower border of the head of femur to the mid portion of the head is ideal, whereas the safety spot (even in the 23% of cases with high femoral artery bifurcation) is at the mid-portion of the head of femur.6
COMPLICATIONS
The overall incidence of complications of femoral access was around 6% in 1990s7 but with advances in hardwares it is now around 2%.8 Various factors that are associated with higher incidence of complications include inappropriate puncture technique, larger French sheaths, counter-puncture of artery, inadequate compression, repeat procedures, advanced age, peripheral artery disease, high doses of anticoagulation, use of GP IIb/IIIa inhibitors and obesity.9 Analysis from the IMPACT II trial has identified modifiable risk factors, such as early sheath removal, avoiding placement of venous sheaths, and careful monitoring of heparin doses as potential ways of decreasing bleeding risk and complications.10 The common complications include:
- Hematoma: As per a series of 474 patients showed an incidence of 1.3%for a large hematoma (> 10 cm) and 8.9% for a smaller hematoma (< 5 cm).11 It usually requires conservative management; even large hematomas rarely require surgical evacuation until there is an arterial connection or infected hematomas.
- Pseudoaneurysm: Incidence of pseudoaneurysm varies from 0.5 to 7.7% in various series.7 Factors associated with pseudoaneurysm are lower puncture, multiple punctures, and inadequate compression. Smaller pseudoaneurysms of 2–3 cm can be managed conservatively with close follow up or can be closed with ultrasound guided compression of the neck. Those larger than 3 cm rarely close spontaneously and requires either ultrasound guided compression or Doppler guided thrombin injection into the sac. Surgery is reserved if these measures fail.
- Arteriovenous fistula: It is rare with an incidence of approximately 0.4%. It occurs when the artery is punctured through the vein or it overlies the vein. Most of them are small and close spontaneously but a large fistula causing symptoms of high-output failure need to be corrected surgically.
- Acute arterial thrombosis: Occlusion of the femoral artery may occur due to thrombosis or local arterial injury.
- Retroperitoneal hematoma: A higher puncture can cause a leak into the retroperitoneal space. It is a life threatening complication and the diagnosis requires high index of suspicion. The alarming features include unexplained hypotension which may be fluid responsive initially, unexplained drop in hematocrit, pain/discomfort in flanks. It can be sometimes missed even on ultrasound. An adequate evaluation of source of bleeding should be identified and corrected appropriately. Rarely, there can be a diffuse bleeding in retroperitoneal space which is result of coagulopathy and requires urgent correction of the same.5
Closure Devices
Closure by manual compression is the gold standard, however, it has disadvantages of patient discomfort, prolonged bed rest, need of interrupting anticoagulation, and more time of healthcare providers. Vascular compression devices (VCD) improve patient comfort, shorten time for hemostasis, ambulation and discharge. However, studies have shown higher risk of infection and leg ischemia with closure devices. A large randomized trial comparing angio-seal with manual compression showed similar complication rates in both groups; with main advantage of angio-seal being patient comfort with shorter bed rest and immobilization.12
There are two types of closure devices active and passive. Passive ones like FemoStop provides a mechanical compression with a belt with a transparent inflatable bubble. Active VCDs results in immediate closure and includes suture devices, collagen plugs or clips.
Collagen Plug Device: Angio-Seal
It contains a small collagen plug at tip and an absorbable suture. First, the existing arterial sheath is exchanged for a specially designed 6F or 8F sheath with an arteriotomy locator. Once blood return confirms proper positioning within the arterial lumen, the sheath is held firmly in place while the guidewire and arteriotomy locator are removed. The Angio-Seal device is inserted into the sheath until it snaps in place. Next, the anchor is deployed and pulled back against the arterial wall. As the device is withdrawn further, the collagen plug is exposed just outside the arterial wall and the remainder of the device is removed from the tissue track. Finally, the suture which connects the anchor, the collagen plug, and the device is cut below skin level, leaving behind only the anchor, collagen plug and suture, all of which are absorbable.
Other devices include Collagen plug device—Mynx, Cardiva Catalyst (Boomerang), Polyglycolic Acid (PGA) plug device: ExoSeal, Clip device: Starclose, Suture devices: Perclose.
Transcatheter Aortic Valve Implantation (TAVI)
For TAVI, larger sheaths are required and hence the pre-procedure protocol for evaluation of the same involves the CT angiography of the peripheral vessels to evaluate the diameter, iliofemoral axis, tortuosity, calcification and extend of atherosclerosis. A diameter of femoral artery required should be more than or equal to 6 mm so as to accommodate 18F sheath. Closure devices are used post procedure to close the access.6
Radial Access
Over the last decade, the radial access has gained lot of popularity as it is more comfortable to the patient, has very less complication rates as compared to femoral route. However, it has some limitations like frequent radial spasms, limitations of catheter size which restricts its use in complex cases. Studies have shown major advantage of radial access in patients with acute coronary syndrome where larger doses of anticoagulants, GP IIb/IIIa inhibitors and in some cases fibrinolytics are used. Use of radial route has shown reduction in access site complications, overall morbidity and mortality.13 This is due to the superficial location of the radial artery, the extensive palmar collaterals, lack of adjacent veins or nerves, and hence easy and safe hemostasis, and no ischemic squeal or injury of surrounding structures.
Anatomy of Radial Artery
Radial artery is a branch of brachial artery and mostly the bifurcation occurs just below the elbow joint. It passes along the lateral margin of the forearm until it reaches the level of the wrist. The radial artery passes along the lateral margin of the forearm until it reaches the level of the wrist. In the upper forearm the vessel is deep to the body of the supinator longus muscle. In the mid forearm, down to the level of the wrist, it lies between the tendons of the supinator longus and the flexor carpi radialis. The radial artery is usually smaller than the ulnar artery at their origins, but is equal or larger at the wrist as the ulnar artery gives off numerous branches in the forearm.14
Absolute contraindications to radial artery cannulation include inadequate circulation to the extremity, Raynaud syndrome, thromboangiitis obliterans (Buerger's disease), and full-thickness burns or skin infection over insertion site.
Evaluation of palmar arch: When the radial artery is compressed complete, it is essential to have a good palmar arch so as to maintain adequate perfusion of hand.
Modified Allen's Test (Fig. 3)
- Positive modified Allen's test—If the hand flushes within 5–15 seconds, it indicates that the ulnar artery has good blood flow; this normal flushing of the hand is considered to be a positive test.
Fig. 4: The four patterns of ulnopalmar arch patency assessed by plethysmography and pulse oximetry as described by Barbeau et al. (2004). A, B, and C suggest adequacy of patency of palmar arch.
Plethysmography and Pulse Oxymetry for Evaluation of Palmar Arch
On the basis of the modified Allen's test ≤ 9 seconds criteria, 6.3% of patients were excluded from the transradial approach, whereas with plethysmography and pulse oxymetry types A, B, and C, only 1.5% of patients were excluded (Fig. 4).15
Puncture Technique
The patient's wrist is hyperextended and held in place with an arm board and gauze dressing so that the wrist is exposed (Fig. 5). Positioning of the patient's arm and wrist is one of the most important preparatory steps, as hyperextension of the wrist brings the radial artery more superficial and increases success rate.8
The entry site is typically 1–1.5 cm above the junction of the arm and the hand (Typically at the level of second crease). Typically the best approach is to find the area of maximal arterial pulsation. An Angiocath or Jelco can be used to puncture the artery. Initial angle of the needle with the forearm should be between 30 and 45 degrees. Counter-puncture technique is preferred choice of puncture as it gives more chances of successful cannulation. Once pulsatile blood flow is noted the sheath is inserted by Seldinger technique.
Right or Left Radial Approach
The choice between right and left radial approach is more or less related to the operator's preference. The left radial approach (LRA) requires a different table set-up and logistics. The Judkins catheters can be used to cannulate the ostia while going by left radial approach. The LRA is certainly the approach of choice when the Allen's test is negative on the right radial or when a left internal mammary artery (LIMA) angiography is indicated.
Ulnar Approach
The ulnar artery as an access site was an acceptable alternative with lower success rates compared with transfemoral and transradial approaches. The mean success rates were between 38% in intention-to-treat patients and 100% in highly selected cases. The lower success rates can be explained by deeper location of the artery, close proximity to ulnar nerve which can lead to pain if punctured, and also it doesn't have a good bone support for compression.9
COMPLICATIONS
Complications related to radial access are little different than those with femoral route. As the caliber of artery is smaller spams and occlusions are common. Most radial complications are preventable.
Spasm: It is the most frequent complication with radial route. It causes pain and discomfort to patient and also difficulty in manipulations of hardware through it. Risk factors for spasm are patient and operator bound, and include anxiety, age, female gender, improper sheath: lumen ratio, tortuosity, hematoma, and repeated puncture.
Radial occlusion: It occurs in 3–5% of cases and is asymptomatic as a rule; 50% of radial occlusions spontaneously recanalize over time. Predictive factors for radial occlusion include long duration of catheterization, high sheath: artery ratio, heparin dosage, longer sheath, and prolonged compression times.
Bleeding, iatrogenic radial artery perforation: One of the most common reasons for femoral crossover is iatrogenic perforation or dissection of the RA, which can usually be treated conservatively with a proximal pressure bandage. If undetected, perforation may lead to severe forearm hematoma.
Forearm hematoma: Hematoma most commonly results from perforation of a side branch or avulsion of small radial artery from a radial loop. A low threshold to perform a radial artery arteriogram when any resistance to guidewire or catheter insertion is encountered will help prevent this complication. Adequate compression is usually required.
Compartment syndrome is the most dreaded complication of radial artery hemorrhage. A large hematoma causes hand ischemia due to pressure-induced occlusion of both the radial and ulnar arteries. Fasciotomy with hematoma evacuation must be performed as an emergency procedure to prevent chronic ischemic injury. This complication is rare, occurring only once in our early experience; it should always be preventable.
Brachial and Axillary Artery Puncture
The indications of these accesses are similar to those of radial artery puncture. Few advantages of these accesses are these arteries are larger than radial but have disadvantage of higher local complication rates. In present scenario, these would be used as a rescue technique when radial and lower limb arteries are not available.
REFERENCES
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- Babu SC, Piccorelli GO, Shah PM, et al. Incidence and results of arterial complications among 16,350 patients undergoing cardiac catheterization. J Vasc Surg. 1989;10:113–6.
- Cilingiroglu M, Feldman T, Salinger MH, et al. Fluoroscopically-guided micropuncture femoral artery access for large-caliber sheath insertion. J Invasive Cardiol. 2011;23:157–61.
- Altin RS, Flicker S, Naidech HJ. Pseudoaneurysm and arteriovenous fistula after femoral artery catheterization: association with low femoral punctures. Am J Roentgenol. 1989;152:629–31.
- Illescas FF, Baker ME, McCann R, et al. CT evaluation of retroperitoneal hemorrhage associated with femoral arteriography. Am J Roentgenol. 1986;46: 1289–92.
- Turi ZG. An evidence-based approach to femoral arterial access and closure. Rev Cardiovasc Med. 2008;9:7–18.
- Omoigui NA, Califf RM, Pieper K, et al. Peripheral vascular complications in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I). J Am Coll Cardiol. 1995;26:922–30.
- Marso SP, Amin AP, House JA, et al. Association between use of bleeding avoidance strategies and risk of periprocedural bleeding among patients undergoing percutaneous coronary intervention. JAMA. 2010;303:2156–64.
- Muller DW, Shamir KJ, Ellis SG, et al. Peripheral vascular complications after conventional and complex percutaneous coronary interventional procedures. Am J Cardiol. 1992;69:63.
- Mandak JS, et al. Modifiable risk factors for vascular access site complcations in the IMPACT II Trial of angioplasty with versus without eptifibatide. Integrillin to Minimize Platelet Aggegration and Coronary Thrmobosis. J Am Coll Cardiol. 1998;31(7):1518–1524.
- Anderson K Bregondalh M, Kaestel H, et al. Haematoma after coronary angiography and percutaneous coronary intervention via the femoral artery frequency and risk factors. Eur J Cardiovasc Nurs. 2005;4(2):123–7.
- Hermanides RS, Ottervanger JP, Dambrink JH, et al. Closure device or manual compression in patients undergoing percutaneous coronary intervention. J Invasive Cardiol. 2010;22(12):562–6.
- Agostoni P, Biondi-Zoccai GG, de Benedictis ML, et al. Radial versus femoral approach for percutaneous coronary diagnostic and interventional procedures: Systematic overview and meta-analysis of randomized trials. J Am Coll Cardiol. 2004;44:349–56.
- Haerle M, Hafner HM, Dietz K, et al. Vascular dominance in the forearm. Plast Reconstr Surg. 2003.111:1891–8.
- Barbeau GR, Arsenault F, Dugas L, et al. Evaluation of the ulnopalmar arterial arches with pulse oximetry and plethysmography: comparison with the Allen's test in 1010 patients. Am Heart J. 2004;147:489–93.