biology

Tessys method

Tessys method is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Tessys method rather than just read about it. In short: The TESSYS method (transforaminal endoscopic surgical system) is a minimally-invasive, endoscopic spinal procedure for the treatment of a herniated disc. It was a further development of the YESS method by the Dutch Dr Thomas Hoogland in the Alpha Klinik in Munich in 1989 and was first called THESSYS (Thomas Hoogland EndoScopic SYStem).

Key takeaways

Tessys method belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Tessys method to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Tessys method from memory before moving on to harder problems.

Reference excerpt

The TESSYS method (transforaminal endoscopic surgical system) is a minimally-invasive, endoscopic spinal procedure for the treatment of a herniated disc. It was a further development of the YESS method by the Dutch Dr Thomas Hoogland in the Alpha Klinik in Munich in 1989 and was first called THESSYS (Thomas Hoogland EndoScopic SYStem). The procedure involves performing a small foramenotomy and removal of soft tissue compressing the nerve root.

Concept With the Tessys method, the surgeon removes the herniated portions of the disc using posterior lateral endoscopic access. This surgical method for spinal disc herniations is especially gentle for the patient. During the procedure, the patient is positioned either in the lateral or prone position, and local anesthetic is administered, usually in combination with sedation. The patient remains responsive, and typically general anesthesia is not necessary. The surgeon removes the herniated disc tissue through an access tube of mere millimeters via the intervertebral foramen. With special instruments, the surgeon progressively and gently dilates to access the disc without disrupting the surrounding muscles or conjunctive tissue.

History The first blind transforaminal discectomy was done by Parvis Kambin in 1973 with Craig's canula's. The Tessys method was a further development of the existing YESS method (American Anthony Yeung) by the Dutch Thomas Hoogland in 1989 in Munich by reaming a few mm's from the SAP (Superior Articular Process). As of January 2018, more than 400,000 patients worldwide are operated with the TESSYS method. Most of them with the original joimax reamers or the newer safer MaxMoreSpine drills also developed and patented by Dr Thomas Hoogland The system was introduced in the Netherlands in 2004 under the acronym PTED (Percutaneous Transforaminal Endoscopic Discectomy) by orthopaedic surgeon M. Iprenburg, who has since then successfully used the procedure with over 2600 of hernia patients with the joimax reamers.

Indication The Tessys method is suitable for most prolapsed discs, regardless of the anatomical position. Another spinal indication for the Tessys procedure would be cauda equina syndrome, in a case where conservative methods of treatment failed to ameliorate the pain, or if only surrounded nerves are affected. Every intervertebral surgery requires a prior detailed discussion with the patient and imaging diagnostics such as MRI, CT scans and/or X-ray. Monitoring of the compressed nerves and associated pathways is indicated due to the proximity of surgical manipulations that are in contact with nerve roots and/or the spinal cord. Monitoring modalities indicated are continuous somatosensory evoked potentials and spontaneous electromyography of the muscles supplied by the affected nerve roots. Performing a discogram during the surgery procedure provides additional confirmation of the patient's anatomy and the position of the disc prolapse but might increase the degenerative changes in the disc. .

Surgical procedure To remove a herniated disc, the Tessys method uses a lateral, transforaminal, endoscopic access path via the intervertebral foramen. The surgery takes about 45–75 minutes. During the procedure, the patient is either in the lateral or prone position. The operation is preferable done under analgo-sedation in daysurgery. In Germany patients have however to stay for three days in the hospital to get proper payment from insurance companies. The access to the prolapse is achieved using a three-step guide wire technique: The surgeon gradually dilates through the soft tissue with the aid of C-arm radiographic monitoring and stretches the foramen step-by-step, with little or no disturbance to the surrounding muscles and nerves. Utilizing Tessys via nature's entry point, also known as Kambin's Triangle, preserves the stability of the spinal column. The endoscope features a slim working channel to guide instruments to the anatomy. The surgeon leads the endoscope through the working tube while in surgery. The camera emits pictures and/or video of the operating field to a monitor, while the surgeon uses special surgical instruments to remove the herniated disc material safely, with precision.

Advantages Minimally-invasive surgical access: the risks of bleeding, infection and nerve injury are reduced Less post-operative pain: no wound or muscle pain Short recovery period and fast return to active lifestyle No general anesthetic necessary: the risks of nerve injury or thrombosis are significantly reduced; less cardiac cycle stress Immediate pain relief directly after the surgery procedure in 90% of cases Direct access to the sequester of the herniated disc Cost-saving method due to the reduced length of hospital stay

Disadvantages Steeper learning curve compared to open surgery techniques Costs of instruments and technologies Technically demanding surgical procedure

Studies Studies document the advantages and the success of minimally invasive endoscopic spine surgery. The US research clinic the Cleveland Foundation agrees that the recovery period in patients treated with the Tessys method is accelerated by several weeks to months in comparison to conventionally treated patients. Many other studies document a success rate of more than 93%. In January 2018 more as 3000 publications about endoscopic spine surgery are found in PubMed. Among them 2 RCT's. In the USA a complete new coding system was started for all endoscopic spine procedures. In the Netherlands the procedure was called experimental in 2006.

References

Neurosurgical Focus Feb 2016 / Vol. 40 / No. 2 / Page E7 "Patient radiation exposure during transforaminal lumbar endoscopic spine surgery: a prospective study" Menno Iprenburg, Ralf Wagner, Alexander Godschalx, and Albert E.Telfeian

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Tessys method

Start with the simplest possible case. Write down what Tessys method claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Tessys method before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Tessys method ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Tessys method

In research: Tessys method appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Tessys method in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Tessys method is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bones of the vertebral column, Endoscopy, Neurosurgery, so understanding it makes those chapters shorter.
In everyday life: Look for Tessys method outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Tessys method in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tessys method means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Tessys method out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tessys method in simple terms?

Why does Tessys method matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Tessys method?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Tessys method.