Catheter Length Marks: 5–15 cm vs 5–20 cm on Each Catheter
Neurosurgical catheter length marks compared: why ventricular catheters are marked 5–15 cm, peritoneal and lumbar 5–20 cm, and what each range tracks.
Length marks tell the surgical team how much catheter has been placed. On DESU catheters they are tantalum marks at every centimetre: from 5–15 cm on the 23 cm ventricular catheter, and from 5–20 cm on the 120 cm peritoneal, 100 cm lumbar and 80 cm lumbar drainage catheters. They support tracking of length, placement or advancement.
Key takeaways
- Ventricular catheters carry tantalum marks from 5–15 cm; peritoneal, lumbar and lumbar drainage catheters from 5–20 cm.
- Marks sit at every centimetre within the range, and the rest of the catheter is not marked.
- The marks support length, placement or advancement tracking, depending on the catheter.
- Antibiotic-impregnated versions carry the same tantalum marks as the standard catheters.
The ranges below are for comparing neurosurgical catheters side by side. Our other articles cover why tantalum and radiopacity matter and how marks help when a peritoneal catheter is trimmed.
Which DESU catheter carries which range?
The table sets out the marked range and what the marks do on each catheter.
| Catheter | Length | Marks | The marks support |
|---|---|---|---|
| Ventricular | 23 cm | 5–15 cm | Tracking of catheter length and placement during implantation |
| Peritoneal | 120 cm | 5–20 cm | Length tracking during catheter placement |
| Lumbar | 100 cm | 5–20 cm | Tracking of catheter length and advancement during implantation |
| Lumbar drainage | 80 cm | 5–20 cm | Tracking of advancement and length during catheter placement |
Kits follow the catheters inside them. The ventriculoperitoneal catheter kit has 5–15 cm on the ventricular catheter and 5–20 cm on the peritoneal catheter. The lumboperitoneal catheter kit has 5–20 cm on both of its catheters. All are silicone catheters with tantalum marks.
What do the numbers 5–15 and 5–20 actually describe?
They give the first and last marked centimetre, not the length of the catheter. Marks sit at each centimetre between those points, so a 5–15 cm range has 11 marks across a 10 cm zone, and a 5–20 cm range has 16 marks across a 15 cm zone.
Two things follow from that. First, the marks do not run the full length. On a 23 cm ventricular catheter the marked zone covers a large part of the catheter, while on a 120 cm peritoneal catheter it covers only a short section. Second, the range alone does not tell you which end the count starts from, so take that from the instructions for use and the catheter itself before relying on a reading.
What are the marks for on a ventricular catheter?
A ventricular catheter is the proximal catheter: it carries CSF from the ventricular system into the shunt. Its 24 drainage holes sit in the proximal section, in four rows of six, so where that section ends up depends on how far the catheter is passed.
The marks help answer that question: they support tracking of catheter length and placement during implantation. The surgeon can read a mark during the pass and record it. The depth itself is a clinical decision made for each patient.
What are the marks for on a peritoneal catheter?
The peritoneal catheter is the distal catheter of a shunt, carrying CSF into the peritoneal cavity. It is supplied long, at 120 cm, and its marks support length tracking during placement.
Compared with the ventricular catheter, the job is less about one precise depth and more about having a readable reference on a long, flexible tube. The marked zone is the same on the peritoneal catheter in a VP kit and in a lumboperitoneal kit. Our trimming article goes through that step in detail.
What are the marks for on lumbar and lumbar drainage catheters?
On these catheters the marks track advancement as well as length. A lumbar catheter is threaded into the lumbar subarachnoid space through a Tuohy needle, so the team needs to follow how far it has travelled as it goes in.
- The lumbar catheter kit is for shunting. Its 100 cm catheter, 0.8 mm inner and 1.6 mm outer diameter, comes with a 14 G Tuohy needle, guidewire and fixation tab.
- The lumbar drainage catheter kit is for external drainage. Its 80 cm catheter has the same diameters and carries CSF from the lumbar region to an external drainage system.
Both have the 5–20 cm range and 24 drainage holes in four rows of six. So the range will not separate the two on a shelf or in an order. Length and kit contents will.
Why is the range not the same on every catheter?
The difference fits the anatomy. A ventricular catheter is short and passes a limited distance from the skull into the ventricle, so a 5–15 cm zone falls within its 23 cm length. Peritoneal and lumbar catheters are much longer and are placed along longer paths, which fits a marked zone that continues to 20 cm.
In day-to-day use, the catheter gives no reading beyond the end of the marked zone, so the team should know the range before the case starts. The surgeon and the instructions for use decide how the marks are used in any given procedure.
Do antibiotic-impregnated catheters carry the same marks?
Yes. Tantalum length marks appear on both the standard and the antibiotic-impregnated versions of the ventricular, peritoneal, lumbar and lumbar drainage catheters, with the same dimensions. Antibiotic-impregnated catheters are orange and standard ones white, so the colour tells the two apart. The marks do not.
The 31 cm ventricular catheter of the EVD-010 (1.5 mm inner, 3.0 mm outer diameter) is not in the table above. If your protocol depends on marks on an EVD catheter, our product specialists can confirm the details for the configuration you are ordering.
Talk to a DESU product specialist
If you need the marking details for a specific catheter or kit, email sales@desu.tr, use the contact page, or request a quote. A DESU product specialist can help you compare the range across your configurations.
Frequently asked questions
Are the marks on DESU catheters printed?
They are tantalum length marks. The catheters themselves are radiopaque silicone, and their position can be followed under imaging.
Does a 5–20 cm range mean the catheter is 20 cm long?
No. The range shows where the marks sit. The catheters with this range are 80 cm, 100 cm and 120 cm long.
Are there marks on every centimetre?
Yes, within the range. There is a mark at each centimetre from the 5th to the 15th on the ventricular catheter and from the 5th to the 20th on the peritoneal, lumbar and lumbar drainage catheters.
Should the mark reading go in the patient record?
Whether and how to record it is set by your hospital’s protocol and the surgeon. Many teams note the placement reading in the procedure record so that later checks have a reference.
Related standards
- ISO 13485: Medical devices — Quality management systems
- ISO 10993 series: Biological evaluation of medical devices