Distal cephalic vein access for right heart catheterization from the anatomical snuffbox

Corresponding Author:

Hady Lichaa
Ascension Saint Thomas Heart Rutherford Institution,
Medical Center Parkway-Suite 201,
Murfreesboro,
TN ,
USA,
:

Received date: July 12, Accepted date: July 26, Published date: August 02,

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Abstract

Distal radial artery access for Left Heart Catheterization (LHC) from the anatomical snuffbox has become more prevalent in clinical practice due to its multiple well described advantages. If an associated Right Heart Catheterization (RHC) is required, it is usually performed from the antecubital area or distal medial arm access. This requires a dual procedural field preparation which adds more time, patient inconvenience, radiation exposure to the operator as well as suboptimal ergonomics.

We hereby present a new technique for right heart catheterization from a distal cephalic access. This novel approach offers many advantages: Patient comfort, ease of setup, operator convenience in access/ergonomics, reduction of radiation exposure and simultaneous arterial and venous hemostasis with the same distal radial compression device, allowing for improved efficiency and better patient throughput.

Keywords

Anatomical snuffbox • Right heart catheterization • Distal cephalic vein access • Distal radial artery access • Hemodynamic assessment

Introduction

This is a review of a novel technique involving the performance of a RHC from a distal cephalic vein access in the anatomical snuffbox [1].

Radial artery access has clearly demonstrated its superiority over femoral access, with regards to cardiac catheterization procedural morbidity and mortality, in patients with acute myocardial infarction [2,3]. With the radial artery gaining popularity as a default access site for LHC in most parts of the world, some interventional cardiologists are nostalgic about the days when LHC and RHC can be performed from the same procedural field in the groin, rather than two separate fields in the arm [4] (Figure 1). Two separate fields in the upper extremity for arterial and venous access are not only inconvenient and non-ergonomic for the patient, staff and operator alike, but it leads to more radiation exposure to the operator and requires two separate hemostasis methods, which increase total procedural time and slows patient throughput in the catheterization laboratory (cath lab).

Literature Review

The need for an alternative venous access site in the upper extremity

One may ask: Why not access one of the satellite radial veins which course alongside the radial artery?

Well, these radial veins are often too small to accommodate a 5/6F sheath, even after application of a tourniquet around the distal forearm. To solve this problem, one would have to think “outside the box” with regards to alternative venous access sites. This can be safely achieved in the anatomical snuffbox.

Distal radial artery access for Left Heart Catheterization (LHC) from the anatomical snuffbox has become more prevalent in clinical practice due to its multiple well described advantages [5]. The distal cephalic vein originates from the dorsal metacarpal veins of the hand and courses through the anatomical snuffbox, in the superficial fascia overlying the distal radial artery [6] (Figure 2). It often has a similar size as the distal radial artery and this can be significantly increased with a tourniquet placed under the drape at the distal forearm right before venous access (Figures 3 and 4). The compliance of venous wall allows it to handle sheath sizes from 5 to 6 French (F) depending on the size of the patient and the vein itself. One important advice is to avoid the usual aspiration and flushing of the sheath side port after insertion, because the vein often spasms at the tip of the sheath and negative aspiration will often cause air bubbles to appear, from suction through the sheath valve. If one would like to flush the sheath, it is advisable to open the sheath side port and let it passively bleed, then flushing the sheath with saline afterwards.

Advantages of distal cephalic vein access

RHC and LHC from the anatomical snuffbox allow for optimal patient comfort, since the hand is positioned in a neutral position alongside the patient’s body. This reinforces patient satisfaction even more than in traditional radial access, which requires abduction and external rotation of the arm (less comfortable for obese patients and associated with more radiation exposure to the operator).

This technique also allows for a more comfortable procedural setup for the cath lab staff. If the operator depends on the nursing staff in getting sterile intravenous access in the antecubital fossa ahead of the procedure, this eliminates this need, hence saving time and avoiding the complexity of removing the transparent adhesive dressing, in the middle of field of access, in a sterile fashion.

This distal cephalic vein approach to RHC is also a much more ergonomically friendly to the operator, who can manipulate and torque the catheter much more easily while standing straight, instead of leaning forward and reaching the medial aspect of the patient’s proximal arm.

Additionally it results in a much lower radiation exposure to the operator since right heart catheter manipulation is performed further away from the radiation source (Figure 5). With traditional arm antecubital venous access for right heart catheterization, the operator’s hand is very close to the radiation source while advancing the right heart catheter. Conversely, with this new technique, the operator’s hand is at least 40 cm-50 cm further away from the fluoroscopy field which significantly reduces radiation exposure.

Another advantage lies in the use of one hemostatic compression device for both contiguous arterial and venous access sites, when compared to the traditional approach that requires additional manual hold time for venous hemostasis (Figures 6 and 7). After pulling the radial arterial sheath with the patent hemostasis technique, the venous sheath is pulled, without the need for additional compression. This saves precious time and allows for faster patient throughput in the cath lab, while increasing patient satisfaction. Patients love the minimally invasive approach of getting to both sides of their heart from the “back of the thumb”. They are frequently amazed by it.

Disadvantages of distal cephalic vein access

On the other hand, the major downside of this technique is the long distance to the pulmonary capillary wedge position which is often longer than the 110 cm catheters available on the market, in patient taller than 167 cm. As far as we know, there are no dedicated right heart catheters longer than 110 cm on the current market. Hence, patients taller than that are not good candidates for this technique unless 150 cm flexible peripheral 4F catheters (e.g. 4F angled Navicross catheter-Terumo) are used. The latter technique is performed over a supportive 0.014” wire (e.g. Grandslam [Asahi intec], Spartacore [Abbott Vascular], etc.) with a hemostatic Y valve connected to the back of the catheter, hence allowing for continuous pressure assessment while the catheter is advanced through the right chambers over the wire. Cardiac output can be estimated by the Fick method, however it does not allow for measurement of the cardiac output with the thermodilution method. We are hoping that industry starts manufacturing 170 cm balloon tipped catheters, which allow for the use of this technique in most patients.

Moreover, another disadvantage is the relatively small size of the distal cephalic vein at this anatomical location, which is significantly smaller than the distal arm basilic or brachial veins and smaller than the mid cephalic or antecubital veins. However, with the application of a tourniquet at the distal forearm, 5/6 or even 6/7F thin walled sheaths can be often placed without difficulty. Ultrasound examination prior to draping, while a distal forearm tourniquet is applied, is highly recommended. Identification of a very small venous size at this location before draping saves time and effort. It also allows selection of patients where this technique is not anatomically possible and for a quick change of vascular access strategy from the beginning of the case, hence improving procedural efficiency.

Care must be taken to avoid multiple venous punctures, since veins in this location quickly spasm and become inappropriate for further access attempts. The operator could use the modified Seldinger access technique with the bare needle used for radial access, however if one feels more comfortable with the combined “needle-in-IV” approach for the recommended shallow angle of venous entry, it is also considered reasonable.

Finally, the sharp angle of the cephalic vein relative to the axillary vein and often the presence of a valve at that transition may require an 0.025˝ or 0.018˝ wire for crossing. However, there are four types of anatomical connections between the cephalic and basilic veins [7] (Figure 8), which allow for switching routes to the right heart chambers, by transitioning from the cephalic to the basilic vein, which has a more straightforward course to the heart. Usually, advancement of a bare right heart catheter under fluoroscopic guidance, of course without inflation of the tip balloon before reaching the shoulder, leads to the subclavian vein. If difficulties are encountered in the process, a “road mapped” cephalic venogram would be recommended from the access sheath, with 7 ml-8 ml of iodinated contrast. Clear and efficient venography is achieved with distal forearm manual compression, to augment and accelerate venous outflow.

Technical tips and tricks

Fifteen practical tips and tricks for achieving success with this technique are presented in Table 1.

Table 1: Fifteen practical tips and tricks.

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Conclusion

This novel technique, consisting of performing a RHC from a distal cephalic vein access, right next to the distal radial artery which serves as an access for LHC, is a safe, comfortable, convenient and ergonomic approach with potential for less radiation exposure and faster patient throughput. In other words it is a winning situation for the patient, cath lab staff and operator alike.

References

Indwelling catheters (IDCs) are common devices used for urinary drainage. Nursing staff are often responsible for basic IDC management, with escalation to doctors when complications arise. However, the literature has shown that IDC insertion and management is poorly taught in medical schools and to junior medical staff.1 Limited exposure to IDCs in formative years and reliance on specialist nursing care poses a risk of de-skilling doctors. As a result, patients present to emergency departments unnecessarily or are placed on long specialist outpatient clinic waiting lists when most IDC-related problems can be adequately managed without specialist input.2

Indications for catheterisation

To prevent complications, catheters should be used only when clinically indicated.3 Initially, the least invasive form of catheterisation should be chosen and only advanced once a method is no longer appropriate.

Intermittent ‘in and out’ urethral catheterisation

Indications for intermittent catheterisation include relieving urinary retention, drainage of post-void residual urine, urethral stricture dilatation and obtaining sterile urine specimens. Individuals with certain neurogenic or detrusor muscle dysfunction may have regular self-catheterisation regimens. Depending on the indication, self-catheterisation can vary in frequency from weekly to multiple daily insertions. These patients require adequate knowledge and competency to safely perform self-catheterisation.4 Education and assessment can be obtained from continence nurses and doctors specialising in urinary issues.  

Indwelling urethral catheterisation (short term and long term)

Short-term IDCs are commonly used in hospital for management of acute urinary retention (AUR), urine measurements, bladder irrigations, diversion and drainage of urine after surgery, or for patients requiring epidural anaesthesia.4 Individuals presenting with AUR may require an IDC to remain in situ for several days before attempting a voiding trial. This allows the bladder to regain its tone before attempting a voiding trial. Multiple failed, appropriately timed, voiding trials warrant specialist referral.

Long-term IDC should be avoided and is not a substitute for nursing care for incontinence management. In rare situations, when a suprapubic catheter (SPC) is contraindicated and other methods have failed, a chronic IDC may be needed.4 Safe community practice ensures IDCs are changed every 4–6 weeks. Scheduled IDC changes may vary according to individual needs. However, IDC changes should never persist beyond three months.

Suprapubic catheterisation

In hospital, short-term suprapubic catheterisation is used for AUR management when other methods have failed or for lower urinary tract diversion after surgery or trauma.4–6 In these situations the SPC is a temporary measure. Once efficient urethral drainage is achieved, the SPC can be removed and the fistula will promptly close. Long-term suprapubic catheterisation is needed when urethral catheterisation is no longer feasible or in certain neurological diseases.4,6 Compared with IDCs, SPCs  are easier to clean and change, less likely to block, do not cause urethral erosion, maintain sexual function and reduce enteric microorganism contamination.7 A new suprapubic tract takes 10 days to four weeks to become established. Most institutions wait six to eight weeks before changing a newly inserted SPC. After this time, SPCs are typically changed routinely every four to six weeks.8 An SPC should be replaced immediately once it has been removed, as the suprapubic tract closes rapidly.

Patients with permanent catheterisation are at increased risk of bladder stones and bladder cancer. They require annual bladder ultrasonography and serum renal function investigations. They may also require ongoing urological review and cystoscopy surveillance.

Contraindications for catheterisation

IDCs are contraindicated in patients with abnormalities of the urethra, including false passages, severe strictures, injury or tumour.4 Pelvic injury associated with meatal blood, boggy prostate or perineal haematoma is highly suspicious for urethral injury, and specialist input should be sought before catheterisation. More caution should be undertaken in patients self-catheterising with a urinary tract infection.

SPCs are contraindicated when patient factors increase the risk of trauma or infection with insertion. These factors include coagulopathy, bladder carcinoma, pregnancy, ascites, severe obesity, large ovarian cysts, lower abdominal scar tissue, mesh or adhesions from previous surgeries, pelvic cancer or radiation treatment.4,6 Bladder and prostate cancer seeding along the cystotomy tract is also a potential risk.

Types of catheters

All Australian catheters must conform to Australian safety standards.9 Common catheter materials include polyvinylchloride (PVC), latex and silicone.4 The straight Nelaton catheter is a common, single-use PVC product used for intermittent catheterisation.4 Short-term IDCs are usually made of latex or silicone. Latex IDCs are not routinely used because of allergy risk. However, in the absence of allergy there is no difference in the incidence of urinary tract infections.4 Silicone catheters have larger internal diameters, are usually clear and have been associated with reduced rates of bacterial colonisation. Long-term use is associated with a lower risk of urethritis and urethral strictures, making them the preferred material.4

Catheter coatings were intended to reduce trauma and infections.7 Evidence supporting hydrogel, silver-coated or antibiotic-impregnated catheters is limited.4,8 However, there is a growing trend towards hydrogel catheter use in Australia for self-catheterisation and long-term IDC. Hydrogel catheters become smoother when wet, which reduces urethral friction.10 Some studies have shown that hydrogel IDCs can be left in situ for 12 weeks without complications.10

Catheters have one to three lumens. Single-lumen catheters are hollow tubes allowing unidirectional flow, and are used for intermittent catheterisation and sterile urine collection.3 Double-lumen catheters have an inflatable retention balloon in one channel while facilitating urine drainage in the other channel.3,4 Triple-lumen catheters use a retention balloon in one lumen and allow for bi-directional irrigation in the other two lumens. Triple-lumen catheters are used for bladder irrigations to remove pus, clots and thick fluids from the bladder.4

Catheter size is measured by the external diameter and expressed in French gauge (Fg or Fr; 1 Fr = ⅓ mm). The correct size is determined by patient characteristics, type of fluid drained and indication for insertion.3 Generally, the smallest appropriate gauge should be selected to prevent urethral erosion or stricture formation.3 Catheter lengths vary for adults and children (Figure 1).

Figure 1. A summary of catheter tips, sizes and lengths4

Catheter tips vary in shape. Tip selection is guided by the indication for insertion and anatomical factors. Standard catheters have a rounded tip and a draining distal lateral opening, allowing easy insertion and drainage of clear urine.4 Whistle-tip catheters have an open, bevelled end that improves drainage of viscous fluids but poses increased risk of urethral trauma on insertion.4 Coudè and Tieman tip catheters are rounded catheters with an angulated tip. Both catheters are useful for males with enlarged prostates, high bladder necks and urethral strictures.4 Open-ended catheters result in less bladder mucosal irritation and may be useful for long-term catheterisation.11 

Complications of catheters and management

Complications are reduced when catheters are inserted only when indicated and remain in situ for the minimum time required (Table 1).4,12 Catheter-associated urinary tract infections (CAUTIs) are the most common complication of catheterisation and frequently account for presentations to general practice or the emergency department.13 To a lesser extent, catheter blockages and catheter bypassing are other common emergency department presentations.2
 

   

Infections/colonisation

CAUTIs are the most common nosocomial infection worldwide.4 Of healthcare-associated urinary tract infections, 80% occur in catheterised patients, resulting in increased morbidity, mortality and length of hospital stay.14 CAUTI incidence is reduced by appropriate placement and care of catheters. This includes ensuring insertion is indicated, using aseptic technique, implementing good hand hygiene when handling catheters, maintaining a closed drainage system, ensuring patients are adequately hydrated and providing timely removal.4,14

In patients with a long-term IDC, bacterial colonisation of the urinary tract is progressive and 95% of catheterised patients will have bacterial colonisation at four weeks.15 CAUTIs are defined by the presence of bacteriuria and simultaneous symptoms, including generalised malaise, malodorous urine, urinary colour change and systemic signs of illness.16 Antibiotic therapy should be reserved for patients with symptomatic infections and guided by culture sensitivity to prevent antibiotic resistance.15,16 If a CAUTI is suspected, the IDC should be changed while under antibiotic coverage.

Catheter obstruction

Accumulation of blood clots, crystals, tissue and biofilms can cause obstruction. Urinary retention causes discomfort, increases infection risk, causes autonomic dysreflexia in patients with spinal cord injuries and chronically results in permanent bladder dysfunction from detrusor overstretching.6,17,18 Promoting diuresis through adequate hydration prevents obstruction.4,18 Manually flushing a catheter with sterile normal saline can relieve obstruction. If unsuccessful, the blocked IDC should be removed and replaced immediately.17 Larger catheters with irrigation channels may be required. For instance, >20Fr IDC and bladder irrigations are necessary for clot obstruction.

Catheter bypass

Urine bypassing a catheter occurs for various reasons. These include small IDC size, under-inflated retention balloon, constipation, obstruction and bladder spasms. Bladder spasms are sudden involuntary contractions of the detrusor that result in lower abdominal pain, intense urgency and, potentially, urinary bypass in a neurologically intact individual. Removing a catheter usually eliminates bladder spasms, but when not possible, anticholinergic agents (oxybutynin) or β3-agonists (mirabegron) are needed.17 Prevention of constipation through a bowel care regimen also prevents catheter complications, including leakage and obstruction.4

Trauma

Urethral, prostate or bladder neck injury resulting in false tracts, strictures and bleeding are related to traumatic urethral insertion.4 For correct catheter insertion, refer to Figure 2. Traumatic injury is less likely to occur with appropriate catheter selection, lubrication, correct patient positioning and insertion into a full bladder. Retention balloons should only be inflated inside the bladder, which is indicated by urine return with IDC inserted to the hilt. If there is any uncertainty regarding catheter placement, the balloon should not be inflated. If the patient experiences pain with inflation, deflate the balloon immediately and reassess IDC position as this may indicate the catheter is outside the bladder. IDCs should be used with caution in patients at risk of self-extraction, such as those with dementia or who are delirious. When available, ultrasonography is recommended to evaluate bladder volumes and guide SPC insertions.4,6 Urethral erosion occurs more commonly with catheters of larger gauge, prolonged tension or use.4

Figure 2. Appropriate catheter insertion in male and female patients
Images reproduced with permission from Michael D'Alessandro, from Bergman R. Bladder catheterization. Anatomy Atlases, www.anatomyatlases.org/firstaid/BladderCatheterization.shtml
IDC, indwelling catheter

Referral to the emergency department or urologist

Hospital referral should be made if specialist input is required. This includes instances where catheter removal or re-insertion is unsafe or difficult, perforation is suspected and visualisation of the urinary tract is required. Specialist input should also be sought for sepsis or CAUTIs unresponsive to oral antibiotics, ongoing and uncontrolled bleeding, recurrent catheter obstruction and inadequate pain management. 

Conclusion

Appropriate knowledge and experience of catheter management and associated complications by general practitioners reduces the impact on acute-care facilities. Many issues related to catheters can be safely and adequately managed in the community, resulting in timely management and increased patient satisfaction. Emergent specialist input should be reserved for patients in whom basic measures are unsuccessful or where further harm or life-threatening complications are suspected.

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