The original Seldinger technique was developed in 1953 by a Swedish radiologist named Sven Ivar Seldinger. The method revolutionized the insertion of central venous catheters thereby reducing the number of attempts needed to access the vein; this improved the success rate while also lowering the risk of infection or other complications. In addition, the technique nullified the requirement of using a large-bore needle, which often made a puncture exceedingly difficult.
Peripherally Inserted Central Catheter (PICC Line)
A PICC catheter is a line that is inserted into the patient’s vein, usually in the arm but can also be the leg. A PICC line then works by accessing the large central venous system around the heart. The purpose of the PICC catheter is to provide medication, hydration, nutrition, or liquids to the patient before, during, and after medical treatment. PICC lines are typically used for cancer treatments, liquid nutrition (when the body cannot process regular food and water through the digestive system), antibiotics and anti-fungal medications, and pain relief, along with other medications.
Once the PICC line is inserted, it can also be used to draw blood, receive blood transfusions, and to introduce fluids that are often required for x-rays or other exams.
Medical personnel must carefully monitor a PICC catheter for any complications, including life-threatening blood clots, infection, bleeding, nerve damage, a blocked or torn PICC line, vein damage, or irregular heartbeat.
Original Seldinger vs. Modified Seldinger Technique
The original Seldinger technique used a hollow needle inserted into a vein, a guidewire was then inserted through the needle, and the tip of the guidewire was positioned at the desired final location. The needle was then withdrawn. A dilator was then passed over the guidewire to dilate the vessel. The dilator was then removed, and a catheter was passed over the guidewire and threaded to the final location and the guidewire was removed.
The Modified Seldinger Technique (MST) differed from the original concept in that it was used as a tool to insert a tear-away sheath introducer and replace over-the-needle introducers. Interestingly, this technique increased the accuracy of first-time introducer placement to 75% and then, when combined with ultrasound, the accuracy increased to 95 -100%. Additional benefits of the MST, combined with safety guide wire needles, include reduced exposure of healthcare personnel to inadvertent needle sticks and to the spread of bloodborne pathogens.
Additionally, the MST allows the placement of large-bore catheters in jugular veins, pulmonary arteries, and even hollow organs. With any method that promotes vascular access, there is always the possibility of complications, however, the MST reduces risk by greatly improving the overall accuracy of placement.
What Do Studies Say About MST? Benefits and Considerations
Various studies that compared both the Seldinger Technique and the Modified Seldinger Technique consistently prove that the MST provides a risk-free option thereby avoiding major complications associated with catheterization such as arterial puncture, pneumothorax, hemothorax, and mispositioning. Some studies to consider are:
- Seldinger vs modified Seldinger techniques for ultrasound-guided central venous catheterization in neonates: a randomised controlled trial.
- Modification of Seldinger technique for introduction of femoral lines in newborns.
Modified Seldinger Technique for Neonatal Patients
Central venous catheterization in neonatal patients is difficult for many reasons, including the accessibility of incredibly small veins as well as frequent needle perforation completely through the vein.
The MST is minimally invasive and is ideal for premature neonates because it provides a high percentage of guidewire insertion and successful catheterizations on the first attempt.
When inserting a pediatric catheter, accurate puncture of the vein is critical. Therefore, specialists typically combine the MST with an ultrasound to guide insertion and placement. Inserting a guidewire is more complicated with neonates due to easy displacement and misplacement of the needle in the vein. Due to the success rate of the MST in adults, and older pediatric patients prior to any studies, experts hypothesized that it would work ideally for neonatal patients.
Subsequent studies comparing ultrasound-guided internal jugular vein catheterization techniques in neonates found that the MST was far superior for successful punctures, guidewire insertion, and catheterization on the first attempt (95% vs. 75%). One study included 120 neonates less than one-month-old; researchers examined the success rate of insertion on the first attempt and gauged successful puncture on the first attempt using this model. In addition, they monitored the guidewire’s successful insertion and catheterization on the first attempt.
In conclusion, the results of a successful catheterization on the first attempt for the group using the MST were significantly higher (83% vs. 65%) than the group using the original Seldinger model. Successful insertion of the guidewire also scored higher with the MST (95% vs. 75%). Successful first attempt puncture did not vary much between the two groups.
Due to this evidence, researchers concluded that the MST was significantly superior to the original Seldinger technique for ultrasound-guided internal jugular vein catheterization in neonates and first-try successful catheterization with guidewire insertion.
NeoMedical’s Neonatal Modified Seldinger Technique Introducer Kits
NeoMedical provides products such as the NeoMagic® 1.9/2.0 Fr 30-gauge dilator MST kit for successful implementation of the MST in neonates. The kit includes a sheath dilator and guide wire introducer needle specially designed for neonatal use. Both have been lubricated for easy insertion. The 0.010 nitinol deflection-tip guide wire allows seamless insertion of the sheath dilator into the vein, thereby minimizing trauma. The tear-away sheath includes a funneled entry to ease catheter placement. Success rates have been reported as high as 95-98%.
NeoMedical’s MST introducer kits were specifically designed for neonatal patients and their particular needs.
MST Mini Modified Kits
NeoMagic® MST kits are designed specifically for smaller pediatric patients. NeoMedical’s 2.5/3.0 Fr 30-gauge MST Introducer Kits fill the void by offering access for 2.5 Fr and 3.0 Fr catheters. A 0.010-inch nitinol guidewire combined with an atraumatic soft deflection tip maintains access to the blood vessel. The product’s 30-gauge dilator tearaway design eases entry and provides less trauma for the patient.
Small infants and children require special pediatric catheters therefore vascular access becomes an issue due to the immaturity and small size of their veins. The NeoMagic® Mini MST kits provide a solution to the problem.
Modified Seldinger Technique Introducer Kits and Mini MST Kits are just two examples of the substantial line of vascular access products offered by NeoMedical specifically for neonatal and pediatric patients.