(Frequently Asked Questions)

Q: How to store Doccol MCAO sutures?
A: We suggest 4°C storage.

Q: How long can Doccol MCAO sutures be stored?
A: Doccol MCAO sutures are to be used within 6 months if stored under room temperature in a sealed container, and within 12 months if stored under 4°C - 8°C. Doccol guarantees the suture quality within this time range, and use batch numbers for quality tracing. After 6-12 months the coating texture and binding force may change, customers may still use it at their own risk.

Q: How to use Doccol MCAO sutures?
A : Doccol suggests some modifications of your regular surgical procedures for inducing MCAO models. Please refer to the page MCAO Procedures for more information.

Q: What are the successful rate and infarct variation when Doccol MCAO sutures are being used for inducing MCAO models?
A: The successful rate and infarct variation in each individual experiment differs in a limited range from lab to lab, from performer to performer. In experienced hands, the successful rate could reach 98%, and the standard deviation could be as low as 5% of its corresponding mean value for the infarction volume.

Q: Will Doccol guarantee a successful rate and certain range of infarct variation?
A : No. Doccol Corp will not guarantee any specific successful rate and infarct variation because many factors may affect the successful rate and infarct variation. These factors include the differences of animal species, animal body temperature, brain temperature, blood pressure, respiratory function, and the tissue oxygen level; the occurrence of monofilament dislodging, occlusion/reperfusion duration, surgical skills, and post-surgical animal care.

Q: Why a pilot study is needed to find out the optimal MCAO sutures for my study?
A: Although you may find some information from the literature regarding the suture size, coating length, inserted length, and related surgical procedures; these monofilament parameters may not be optimal for your study because each individual experiment is different. In addition, a stable surgical skill is also very important for you to obtain consistent results. New and inexperienced surgeons need a period of time to command the skills for producing acceptable consistent results, which is the so-called “learning curve”. For these modeling reasons, you will need a pilot study to find out the optimal MCAO suture for your own study design and lab settings. The pilot study will be fundamental for your study design because it may provide you the closest information for your infarct variation, successful rate, and mortality rate.

Q: What is the appropriate coating length for my study?
A: Coating lengths are available from 2-3 mm to 9-10 mm. A super long coating length from 10 mm to 15 mm may also be possible through special request to Doccol. The most commonly purchased MCAO sutures have coating lengths of 5-6 mm and 4-5 mm. A shorter coating length leaves more bare surface area on the MCAO suture, which makes the surgeon feel easier to handle it. However, a shorter coating length may increase the chance of incomplete occlusion in inexperienced hands. If the coated part of the MCAO suture passes over the origin of MCA, the blood from the posterior circulation may reach MCA through the residue space around the uncoated part of the MCAO suture. A longer coating length may increase the chance of complete occlusion; however, its increased contacting area with endothelial cells may cause more traction force on those contacted endothelial cells. Such traction may cause endothelial cell damage when you withdraw the MCAO suture for reperfusion. In a summary, a shorter length may be good for reperfusion while longer length good for permanent occlusion; and the selection of the coating length will depend on your own study design, lab setting, and your surgical skill.

Q: What are the differences between disposable monofilaments and reusable monofilaments?
A: Disposable monofilaments are designed for just one time use for most common experiments, and are not recommended for repeated use. Reusable MCAO sutures are specially designed and manufactured such that they have a more uniformed coating surface and a more rigid bare filament, which make them maintaining their shapes better after their initial use than the disposable ones do. They are designed to use twice and may be ideal for the in vivo efficacy study by using paired-controls, in which the paired animals have the same body weight and use the same monofilament. Such a use of paired-controls may drastically increase the consistence of infarction volume. In a catalog number “Re” stands for reusable.

Q: How to understand Doccol catalog numbers?
A: Doccol catalog numbers are encoded using a basic formula of “UUDD (LL)(PKn)(Re)”. In this formula, “UU” stands for USP “0” numbers, for example, when “UU” equals “40” it stands for a 4-0 USP size; “DD” stands for the diameter in 1/10 and 1/100 mm, for example, when “DD” equals “37” it stands for a diameter of 0.37 mm; “LL” stands for coating length range in mm, for example, when “LL” equals “56” it stands for a coating length of 5-6 mm. The default coating length is >= 5 mm and could be omitted in the catalog number, therefore, 4037 stands for a 4-0 monofilament coated to a diameter around 0.37 mm and a coating length of >= 5 mm; “PKn” stands for the amount of filaments that will be packed in a plastic tube. For example, “PK10” stands for 10 monofilaments being packed in a plastic tube. If “PKn” is being omitted in a catalog number, it means a single monofilament; “Re” stands for reusable.

Some old catalog #s, such as 40-3033PK10, 50-3033PK10, 50-3033PK5Re, 60-1720PK10, 60-1720PK5Re, 70-1720PK5Re, and 70-1720ReL10 are kept for the convenience of retrieving some product-related information. These products have a broader range of diameters than that of our new products. Please refer to their product descriptions for more information. Under the “My Special Design” subcategory, the catalog numbers are encoded as “UUSP (Re)”, wherein “UU” and “Re” stand for USP “0” numbers and reusable filaments, respectively; “SP” stands for special. The diameter and coating length are options that should be selected to specify your MCAO sutures while you place your order.