Arrow Int PA Catheter
Another device was a 7-Fr
balloon-tipped catheter (7 F, single lumen; Arrow Int, Reading,
PA) used by Diab et al (Figure 16 ). After accessing the CS
through either right femoral or left subclavian veins and before
contrast injection, the balloon was inflated by air to obstruct the CS
and contrast aspiration was performed using a syringe. In order to
determine the volume of extracted contrast, reduction of patients’ blood
Hct from Hct levels in CS blood was calculated and the result was
divided by the patients’ Hct. Finally, the result of this equation was
multiplied by the volume of aspirated blood from the CS. All the
procedures are done without any failures. However, direct CS cannulation
was just performed successfully in six patients and CS quadripolar or
decapolar catheters were used to help cannulation in the remaining 12
individuals. Contrast aspiration was performed through a balloon-tipped
catheter in 10 patients or direct extraction from the sheath in the
other eight participants. Although patients who underwent CS contrast
removal through the balloon catheter had remarkably higher time to
clearance of the contrast compared to the direct aspiration group, the
fraction of extracted contrast was not significantly different between
groups. The possible mechanisms for shorter contrast clearance time in
those undergoing CS contrast extraction via the sheath might be
associated with the faster rate of aspiration and wider sheath caliber.
Also, the sheath tip has a lower probability of collapsing or facing the
vessel wall during the procedure and it also creates a more negative
suction pressure. They suggested the possible safety of CS cannulation
using trans-septal sheath due to its favorable curves and proper
manipulation and rotation with or even without dilator support. They
also claimed the simplicity of this method as well as its
cost-effectiveness without the requirement of advanced technologies.
Despite their suggestion for optimal choice between balloon catheter or
direct sheath is defined by CS caliber in relation to the sheath,
complementary studies are required. Their potential concern on CS
obstruction on limitation of coronary arterial blood flow might be
explained by reactive hyperemia leading to increased microcirculation
after balloon deflation. Additionally, this enhanced coronary transit
time in the context of CS occlusion might be associated with decreased
necessary contrast
volume (93).
● Expected challenges in CS engagement for contrast
removal:
Although the safety and feasibility of CS contrast removal have been
indicated in several animal and human studies and this procedure is
quite accessible in most clinical settings, there are still some
possible challenges that should be considered. Despite its rareness, CS
anatomical abnormalities are one of the culprits in this regard. CS
length of less than 20 mm is considered to be short CS and might be
associated with difficult CS
cannulation (97–99).
Also, the CS can be varied from enlarged to hypoplastic or even absent
in a few individuals. CS enlargement could be either primary or
secondary to other pathologies including unroofed CS, interrupted
inferior vena cava, coronary artery fistula, and total or partial
anomalous pulmonary venous return. The former abnormality is a
unidirectional left to right or a bidirectional shunt between the left
atrium and superior segment of
CS (99,100).
Also, CS manipulation during catheterization or contrast aspiration
might be associated with CS trauma or thrombosis, or ectopia of atria or
ventricles (90).
It seems CS morphology and proper catheter placement might play pivotal
roles in successful cannulation and should be individually assessed.
Moreover, blood loss per coronary injection might be considerable.
Danenberg et al. reported aspiration of 12-16 ml of blood per
injection (90).
This was 16.6 ± 3.23 ml per injection in Diab et al.’s study. Also,
post-procedural hemoglobin was slightly lower in the CS group in the
aforementioned study, but it was statistically insignificant (10.85 ±
1.3 g% vs. 11.62 ± 1.3 g%, P=
0.06) (93).
Patient discomfort, unstable sheath position, and difficulty in
advancing the sheath to the CS ostium have been reported to be some
difficulties during CS
cannulation (100).
Another study reported an approximate 10% of minor myocardial damage
during CS catheter placement, but all complications were not clinically
evident (97).
Another considerable factor might be attributed to CS cannulation time
which has been reported in different ranges. The time was 19.27 ± 3.54
minutes in one study compared to 11.1 ± 9.3 minutes in another
one (80,93).
The equipment, the procedure (angiography versus intervention) as well
as skillfulness of the interventionist might be some possible
explanations for these reported differences.
Contrast extraction from CS seems to be a novel method ultimately
leading to a decrease in CIN incidence among CA/PCI patients. However,
some questions are currently needed to be investigated by further
comprehensive studies. For instance, despite PCI or CA being common in
origin, the required time for completion of each method is quite
different. Acceptable catheter sheath size should also be more
investigated. Appropriate training for proper CS manipulation should
also be considered. The blood loss amount is another potential concern
that needs to be evaluated and probably corrected by returning the
aspirated blood without contrast media to the patient. Normal blood loss
during conventional CA should be less than 300 cc (86). Moreover,
studies are probably necessary to define the exact CS contrast
aspiration time to prevent CIN.
Summary:
CIN in the context of CA and PCI is a major concern. Despite several
proposed methods to prevent CIN, CIN occurs in high rates with high
morbidity and mortality. New means that can reduce CIN is desirable.
Contrast removal from CS has been shown to be such a mean with future
potential in order to decrease CIN risk during coronary procedures with
a great safety profile. Large randomized trials are required to assess
the efficacy and safety of this approach.
Competing interests : Mohammad Reza Movahed has the Patent
holder for the contrast removal device.
Abbreviations:
- BIVA: Bioimpedance Vector Analysis
- CA: Coronary Angiography
- CI: Confidence Interval
- CI-AKI: Contrast-Induced Acute Kidney Injury
- CIN: Contrast-Induced Nephropathy
- CKD: Chronic Kidney Disease
- eGFR: estimated Glomerular Filtration Rate
- Hct: hematocrit
- IQR: Interquartile Range
- IVUS: Intravascular Ultrasound
- LVEDP: Left Ventricular End-Diastolic Pressure
- MOZART: Minimizing Contrast UtiliZation With IVUS Guidance in
Coronary AngioplasTy
- MYTHOS: Induced Diuresis With Matched Hydration Compared to
Standard Hydration for Contrast-Induced Nephropathy Prevention
- N-AC: N-Acetyl Cysteine
- NYHA: New York Heart Association
- OR: Odds Ratio
- PCI: Percutaneous Coronary Intervention
- REMEDIAL II: Renal Insufficiency After Contrast Media
Administration Trial II