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REVIEW ARTICLE
Year : 2023 | Volume
: 9
| Issue : 1 | Page : 18-23
Anatomical snuffbox for interventional cardiology: Hype or hope?
E Thirumurugan
Research Scholar, Srinivas University, Karnataka; Lecturer, Faculty of Allied Health Science, Dr. MGR Educational and Research Institute, ACS Medical College, Chennai, Tamil Nadu, India
Correspondence Address:
E Thirumurugan
Dr. MGR Educational and Research Institute, Chennai, Tamil Nadu
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/jpcs.jpcs_12_23
Cardiovascular catheterization has traditionally been done through transradial access. Vascular complications, primarily radial artery (RA) occlusion, continue to exist despite their rarity. In recent times, interventionalists have reported using the anatomical snuffbox (ASB) or distal transradial approach for cardiac catheterization. This distal radial approach has been promoted to lower the risk of bleeding and vascular access site complications as well as RA occlusion at the forearm. This state-of-the-art review outlines the feasibility and safety of left versus right ASB in interventional cardiology.
Keywords: Distal transradial approach, left anatomical snuffbox, right anatomical snuffbox, transradial access
In 1948, surgical cut-down was used to access the radial artery (RA) and provided the first description of arterial access for cardiac catheterization. The preferred arteriotomy method transitioned from the Sones approach of brachial artery cut-down to the Seldinger and Judkins technique of percutaneous femoral artery access.[1] The first 100 cases of the percutaneous RA approach for coronary angiography were published in 1989 after it was invented by Lucien Campeau at the Montreal Heart Institute (Canada) in 1986.[2] With advancements in technology and equipment, transradial coronary intervention has become the primary technique for coronary interventional treatment around the world.[3] In comparison to femoral access, radial access reduces access-site bleeding due to the easily compressible and superficial anatomy of this artery and improves patient comfort with early mobility after procedures.[4] According to a 2017 Kiemeneij study, left RA cannulation in the anatomical snuffbox (ASB) is practical and safe. This novel technique can address a variety of concerns associated with right distal RA cannulation.[5] This state-of-the-art review outlines the feasibility and safety of left versus right ASB in interventional cardiology.
MethodologyResearch question
The purpose of the systematic review was to evaluate the safety and feasibility of right and left-ASB approaches in the field of interventional cardiology as an alternative to traditional radial approaches.
Research protocol
We searched for original articles examining the safety and feasibility of using ASB in the field of cardiology. The review included studies comparing the right ASB with the left ASB approach, the right ASB with the conventional right radial approach, and the left ASB with the conventional left radial approach. Review articles, systemic reviews, meta-analyses, case reports, and editorials as well as qualitative studies were excluded.
Literature search
An extensive literature search was conducted on various scientific literature databases, including PubMed/MEDLINE, Science Direct, Google Scholar, and Web of Science, using the following keywords: Anatomical snuffbox, Distal RA and Left anatomical snuffbox, and Right anatomical snuffbox. The literature search was conducted by two independent reviewers. The applicability of each study and publication to the theme of our review was carefully considered. Articles with a conventional radial approach that were compared with the right or left anatomical snuffbox approach for coronary interventions were also considered. This systematic review of clinical trials was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement [Figure 1].
Figure 1: The systematic review methodology according to the recommendations for systematic reviews and meta-analyses Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. ASB: Anatomical snuffbox Anatomy The anatomical snuffbox is a surface anatomy feature defined as a triangular depression on the dorsum of the hand near the base of the thumb. This region is more apparent when the palm is flat on the table and the thumb is extended and lifted off the table. The use of the depression as a method of placement for the inhalation of powdered tobacco, also known as dry snuff, gave rise to the name “ASB,” which was first documented in the medical literature in 1850.[6]
Snuffbox Puncture TechniqueThe anatomical snuffbox can be used to gain radial access for coronary angiography and percutaneous coronary intervention. The patient places his left or right upper arm over a cushion and bends the elbow just enough for the hand to rest comfortably in the groin area. An anatomical snuffbox was injected with 1 ml of lidocaine hydrochloride using a 21-gauge needle to establish local anesthesia. After that, a puncture was made utilizing the anterior wall puncture technique using a 21-gauge open needle. A 0.025-inch straight wire is introduced after a successful puncture, and then, the radial sheath is placed. To prevent arterial spasm, 0.2 mg of nitroglycerin, 2.5 mg of verapamil, and 3000 units of unfractionated heparin dissolved in 10 ml of saline solution are administered after successful cannulation [Figure 2 ].[7]
ResultsThe initial search for clinical trials comparing ASB approach to the traditional radial approach for interventional or diagnostic coronary interventions yielded 2530 potentially interesting publications. Additional inclusion/exclusion criteria were used, and a total of 13 articles were obtained.
Procedural FeasibilityChugh et al. recently conducted a study on 545 patients undergoing coronary procedures. Puncture success was defined by the author as the successful advancement of the radial sheath. The same author defined “puncture time” as the time period between the initial skin contact of the puncture needle and the effective cannulation of the access artery with the sheath wire.[8]
Studies comparing the right anatomical snuffbox with the left anatomical snuffbox approach
Three (60%) of the five studies reported an increased rate of puncture success for the left ASB approach for coronary intervention. In 1 (20%) study, it is depicted that the rates of puncture success for the right and left ASB approaches were similar. In total, the left ASB was the best approach or superior for coronary intervention in 3 (60%) studies out of 5. In 1 (20%) article, the left ASB was found to be inferior [Figure 3]. The articles were mentioned in tabular form [Table 1] along with the relevant findings.
Figure 3: Feasibility of a left anatomical snuffbox approach for coronary intervention based on successful cannulationStudies comparing the right anatomical snuffbox with the conventional right radial approach
Through a systematic review of the data from six clinical trials, we sought to compare the right ASB with the conventional right radial access (RRA) for diagnostic or interventional coronary procedures. Five (83.3%) of the six studies reported a lowered rate of puncture success for the right ASB approach for coronary intervention [Figure 4]. Moreover, there was an indication of a higher failure rate of right ASB than the conventional RRA. The most notable finding of this review was that the right ASB approach for coronary intervention took a longer time to puncture than the conventional right radial approach in 5 (83.3%) of the six studies. The articles were mentioned in tabular form [Table 2] along with the relevant findings.
Figure 4: Feasibility of a right anatomical snuffbox approach for coronary intervention based on successful cannulation. DRRA: Distal right radial access, RRA: Right radial access
Table 2: Right anatomical snuffbox versus conventional right radial approachStudies comparing the left anatomical snuffbox with the left conventional radial approach
A comparison of the left ASB technique to the conventional left radial approach did not exist in the literature or was not yet described. The assumed reasons for this are as follows: Most operators use the right conventional radial approach rather than the left because catheter manipulation can be performed from the patient's right side without physical discomfort to the operator. Saleem et al.[18] showed that there was a longer puncture time in Left distal transradial approach (LDRA) compared with RRA [Table 3].
Table 3: Left anatomical snuffbox versus conventional right radial approach Procedural Safety Chugh et al. recently conducted a study on 545 patients undergoing coronary procedures. The distal radial artery occlusion on color Doppler ultrasound was defined by the same author as flow reversal in the RA in anatomical snuffbox. The term vascular access site complications (VASC) were formulated by the same author and refers to conditions such as compartment syndrome, pseudoaneurysm development, dissection, and arteriovenous (AV) fistulas. Forearm hematomas (5 cm) and hematomas limited to the hand (due to bleeding and extravasation) were also included. The same author defined non-VASCs as any access site-associated permanent or temporary motor or sensory nerve injury, including localized transient numbness and paresthesia at 1 and 6 weeks, as confirmed by a neurological assessment.[8]
Studies comparing the right anatomical snuffbox with the left anatomical snuffbox approach
Four (80%) of the five studies reported a 0% rate of RA occlusion for the left ASB approach for coronary intervention, whereas the right ASB approach reported RA occlusion in two (30%) of the three studies [Table 4].
Table 4: Procedural safety of anatomical snuffbox for coronary intervention based on complicationsStudies comparing the right anatomical snuffbox with the conventional right radial approach
Three (60%) of the five studies reported an increased rate of RA occlusion for the conventional right radial approach than the right ASB approach for coronary intervention. Vascular access complications such as hematomas were reported at a higher rate for the right ASB approach than the conventional radial approach in two (40%) of five studies, whereas in another two (40%) of five studies, an increased rate of hematomas was reported in the conventional radial approach than the right ASB [Table 5].
Table 5: Procedural safety of right anatomical snuffbox versus conventional right radial approach for coronary intervention based on complicationsStudies comparing the left anatomical snuffbox with the left conventional radial approach
We sought to compare the left ASB with the conventional left radial access for diagnostic or interventional coronary procedures. Mehmet Kış et al. (2022) reported a 0% rate of RA occlusion in both the left DRA and L-RRA. The increased rate of AV fistulas was reported in the L-RRA rather than the L-DRA. In addition, the increased rate of RA spasm was reported in L-DRA rather than LRRA [Table 6].
Table 6: Procedural safety of left anatomical snuffbox versus conventional left radial approach for coronary intervention based on complications Pros of Anatomical Snuffbox The left snuffbox technique is more attractive to many interventional cardiologists because it can overcome several drawbacks of the traditional left radial approach, even though both the left and right snuffbox procedures are feasible for the majority of the patients. The catheter is easily manipulated in the same way as the femoral approach in the traditional left radial approach while offering more backup support than the right radial approach. Despite these advantages, many interventionists prefer the right radial approach for a variety of reasons:
For needling, operators frequently need to travel to the patient's left sideBending across the table to patients' left wrists increases the risk of radiation exposure for operatorsThe left snuffbox method is used by drawing the patient's left hand towards the right inguinal area. In this position, operators can perform needling in the same way as the conventional right radial techniqueIn addition, the left snuffbox method is particularly beneficial for right-handed people. It enables patients to immediately utilize their dominant hand without restriction following the treatment, facilitating their return to work. Cons of Anatomical SnuffboxThe snuffbox technique can reduce the guiding catheter's effective length by about 3–5 cm compared to the traditional radial access. As a result, catheters may not reach the coronary ostium, particularly in cases when patients are tall and the arteries are tortuousIn the anatomical snuffbox, the RA is smaller in size, more tortuous, and more prone to spasm, making it harder to needle than that using the traditional radial approachDue to the closeness of the radial nerve and the carpal bones, needling can easily produce discomfort by irritating the periosteum and nerveSheaths >7 Fr are challenging to introduce since the RA is small in the snuffbox. Conclusion In terms of procedure efficiency, safety and the recent implementation and development of the left or right anatomical snuffbox approach had a significant impact on interventional cardiology. This technology will play a significant role in the future of interventional cardiology as advancements eliminate the drawbacks of the traditional radial approach for coronary procedures. A larger study demonstrating the safety and feasibility of the left or right anatomical snuffbox approach as well as addressing technical difficulties would be required.[20]
Acknowledgments
Researchers thankfully acknowledge Dr. Kalpana Devi, Principal, and Dr. Kalavathy Victor, Director of Allied Health Science of Dr. M. G. R. Educational and Research Institute for active guidance. We want to thank Ms. Sakathi Varsha for his special contribution to drawing original pictures in [Figure 1].
Ethics clearance
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Nil.
Conflicts of interest
There are no conflicts of interest.
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