Insertion of the Modified Pinnacle sheath for Reduction Of Vascular Events (IMPROVE) Study

Abstract

Objectives. The aim of this study was to prove the efficacy and safety of the Pinnacle TIF Tip sheath during the performance of diagnostic and interventional cardiovascular procedures. Background. Vascular sheaths have been used for almost 30 years to avoid trauma to the subcutaneous tissues. Terumo Interventional Systems has created a vascular sheath with a sheath-dilator technology. Methods. In this consecutive studied population of 146 patients undergoing diagnostic and therapeutic interventions, a total of 197 sheaths were inserted: 146 sheaths were inserted in the arterial system and 51 sheaths were inserted in the venous system. The sheaths range from 6 Fr to 7 Fr, and were 10 cm in length. The purpose of the study was to evaluate the durability, penetration force, visibility, trackability, stiffness, kinking, peeling and fish-mouthing during the insertion of the Pinnacle TIF Tip sheaths, as well as to assess access-site complications related to the insertion of the Pinnacle TIF Tip sheath. Results. All vascular sheaths but one surpassed the durability and kinking test, none of the sheaths had peeling or fish-mouthing, and 95% of the inserted sheaths advanced with minimal force. All were well visualized during fluoroscopic guidance. Only 1% of hematomas were related to the insertion of the Pinnacle TIF Tip sheath. Conclusion. This pilot study clearly demonstrates the benefits of using a better-fit sheath-dilator technology, decreasing the trauma to the subcutaneous tissues, with minimal penetration forces.

Key words: sheaths, cardiovascular procedures

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Introduction

The use of the vascular sheath was initiated three decades ago to protect the subcutaneous tissue and vessels from excessive trauma during the initial advancement of diagnostic and therapeutic catheters. Sheaths are constructed from short segments of thin-walled catheter material, often Teflon, and are sized according to the largest catheter they will accommodate. They are placed into the vessel at the puncture site and left for the duration of the case, usually so that all wires and catheters pass through them. A hemostasis valve is attached on the trailing end so that catheters and guide wires can be exchanged without blood loss. A flushing side port is provided for pressure monitoring, fluid or drug administration, as well as blood withdrawal for anticoagulation monitoring, if required.

Insertion of the sheath is performed with a dilator in its lumen. Dilators are short, stiff, thick-walled sections of catheter, available in a variety of sizes, with a long, tapered end that spreads tissues more easily than diagnostic or therapeutic catheter.

Today’s technology allows sheath insertion without skin nick preparation and subsequent soft tissue plane dissection; however, not all available sheaths are made and designed equally.

The Terumo^® Pinnacle TIF Tip^™ sheath (Figure 1) offers an introducer sheath transition, allowing an atraumatic insertion, with minimal penetration force applied.

The purpose of the study was to test the performance of the TIF Tip sheath, as well as to assess access-site complications related to the insertion of the TIF sheath in 146 consecutive patients referred for cardiovascular procedures. Every sheath was analyzed post-procedure by visual inspection. The following variables were assessed:

1. Durability: Defined as how well the system withstood use during the procedure.
2. Fish-mouthing: An ovaling of the distal opening of the sheath, usually caused when the sheath slips back off the dilator, or there is a dilator-to-sheath transition mismatch.
3. Kinking: Any buckling or bending of either the sheath or dilator shaft during advancement over the wire.
4. Peeling: The sheath folding over on itself, resulting in bunching up on top of the dilator.
5. Penetration force: The subjective measure of the pressure (force) required to insert the sheath and dilator into the vessel. 
6. Stiffness: Represents the support and stoutness of the shafts of both the dilator and the sheath.
7. Trackability: The ability of the sheath set to follow the wire, and not buckle or kink.
8. Visualization: The ability to visualize the system under fluoroscopy, computed tomography (CT), or ultrasound.

Methods

Between September 11, 2009 and January 21, 2010, a total of 146 subjects were enrolled in the trial. Study subjects underwent both diagnostic and interventional procedures. All patients were prospectively followed throughout hospitalization, with each patient evaluated post procedure, post sheath removal, and at 24 hours post procedure.

The femoral vascular sheaths included sizes 6 French (Fr) and 7 Fr, and were 10 cm in length. Every single vascular sheath inserted was analyzed by visual inspection after removal to evaluate durability, fish-mouthing, kinking, and peeling. None of the sheaths inserted were forced to penetrate the subcutaneous tissue at the expense of damaging the vessel wall or creating a kink in the wire.

Procedures

All patients received moderate sedation and infiltration with local anesthetic at the groin site. Before the insertion, fluoroscopy was performed on every individual to identify the femoral head and guide the insertion of the sheath, with the goal of entering the common femoral artery over the medial mid-femoral head. A modified Seldinger technique was used to cannulate the common femoral artery without performing a skin nick.

Upon gaining vascular access, patients received anticoagulation to keep their activated clotting time (ACT) over 200 seconds. After completion of the diagnostic or interventional procedures, all sheaths were removed as long as the ACT was <160 seconds.

Patient sample

A total of 146 consecutive patients, with ages ranging from 33 to 91 years, received arterial and venous sheaths, of which 131 sheaths were placed in the right common femoral artery. Fifteen sheaths were placed in the left common femoral artery due to a previous right common femoral arterial to popliteal artery bypass (4 patients), previous right hip replacement (4 patients), and left common femoral access gained for abdominal aortography and lower extremity run off, with the intentions to proceed with peripheral intervention if indicated (7 patients).

A total of 51 patients had a concomitant venous access, 50 via the right common femoral vein and 1 via the left common femoral vein. All venous access was obtained for the performance of right heart catheterizations.

Data collection and analysis

To assess the penetration force and the resistance accessing the common femoral artery or common femoral vein, a scale was created to measure the applied force during advancement of the sheath. A grade of 0-1 was given when no force or minimal force was applied; grade 2 was given whenever the vascular sheath needed to be torqued at the entry site in order to be advanced; and grade 3 was given whenever the use of the dilator preceded the insertion of the vascular sheath to create a channel.

Results

The total number of vascular sheaths evaluated was 197, of which 146 were inserted into the arterial system and 51 in the venous system.

As shown in Figure 2, a total of 159 inserted vascular sheaths, 81% of the sheaths studied, had insertion applied force graded as 0-1; another 27 inserted sheaths, representing 14% of the studied sheaths, were graded as 2; lastly, 11 inserted sheaths, representing 5% of the studied sheaths, were graded as 3.

Visual analysis of the sheaths showed only one sheath with appreciable kinking, in a patient that was morbidly obese, and required an exchange of the 6 Fr Pinnacle TIF Tip sheath for a 7 Fr metal sheath.

None of the sheaths had evidence of peeling or fish-mouthing. All sheaths but one surpassed the durability test (the one with kinking) with excellent trackability, stiffness during insertion, and visualization. Despite the different grades of penetration forces, all TIF Tip sheaths could be inserted without the need of skin nick preparation, blunt dissection, or use of smaller dilators.

Of the 197 sheaths, 2 small hematomas (1.0%) were directly related to the sheath insertion (Figure 3). One hematoma was related to the kinked sheath that required the upgrade from a 6 to 7 Fr metal sheath, and the other required an upgrade from a 6 to 7 Fr Pinnacle, with resolution of the hematoma post sheath removal. The hematomas were small, < 3 cm in diameter. An additional 3 small hematomas (1.5%), again < 3 cm in diameter, were seen post procedure, in patients that could not keep their limb straight for the mandatory bed rest.

Finally, 2 large hematomas (1.0%) were seen. One was a retroperitoneal hematoma that manifested with hypotension at the end of an interventional procedure, the culprit being a small arterial laceration at the junction of the right external iliac and proximal right common femoral arteries, treated successfully with prolonged balloon inflation and reversal of anticoagulation. The other hematoma was 5 cm in diameter, seen post sheath removal in a patient with prostatic enlargement and subsequent straining during micturition; it was successfully treated with prolonged manual compression.

Discussion

Vascular sheaths have been used for almost three decades, with the initial indication for use whenever multiple catheter exchanges were planned. However, today, the use of the vascular sheath is mere routine during any percutaneous cardiac or peripheral procedure.

Over the last few years, sheath technology has gradually improved to reduce further trauma and complications during the performance of diagnostic and interventional procedures. Terumo Interventional Systems has developed a sheath technology to reduce the resistance and increase the ease in placement of vascular sheaths. The Pinnacle TIF Tip sheath has a dilator-sheath transition that allows the advancement of the vascular sheath with minimal trauma to the tissues and vessels. The absence of peeling or fish-mouthing seen with the Pinnacle TIF Tip corroborate the transition of the vascular sheath, allowing a better-tapered end to spread subcutaneous tissues.

This evaluation of the Terumo Pinnacle TIF Tip sheath has demonstrated its ease of insertion, with smooth tapering, durability and integrity of the vascular sheath, despite challenging scenarios. All of the inserted sheaths were advanced without the need to predilate the access site with a smaller dilator. Most of the inserted sheaths, 95% of the entire population, could be advanced as a unit, without excessive force applied at the entry site.

The access site complication rate of 1.0% due to the inserted sheath despite anticoagulation use is far below the reported national registries. Overall, there was a 3.5% hematoma rate reported in the study, despite standard anticoagulation, with no vessel thrombosis, distal embolization, or dissection reported with the use of the Pinnacle TIF Tip sheath.

Conclusion

Our study supports the contemporary use of this new vascular sheath technology with the purpose of minimizing discomfort, vessel and tissue trauma, and length of stay post procedure, translating into cost reduction for hospital administrations and space-saving strategies for catheterization laboratories, due to the primary avoidance of extra material storage in catheterization laboratory shelves. These findings should be confirmed through a large, randomized clinical trial evaluating the Pinnacle TIF Tip sheath technology head-to-head with other available sheaths.

The authors can be contacted via Dr. Pastor-Cervantes at apastor@pol.net.

References

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3. Baim, DS, Grossman, W. Complications of cardiac catheterization. Baim DS, Grossman W, eds. Cardiac Catheterization, Angiography, and Intervention. 6th ed. Philadelphia, PA: Lippincott, Williams, and Wilkins; 2000.
4. Doyle BJ, Ting HH, Bell MR, et al. Major femoral bleeding complications after percutaneous coronary intervention: incidence, predictors, and impact on long-term survival among 17,901 patients treated at the Mayo Clinic from 1994 to 2005. JACC Cardiovasc Interv 2008 Apr;1(2):202–209.

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Disclosure: Dr. Pastor-Cervantes reports receipt of a research grant from Terumo Interventional Systems. Ms. Robblee and Dr. Nunez-Urquiza report no conflicts of interest regarding the content herein.