Laser surgery

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Laser surgery comprises various surgical methods that use laser technology (instead of a scalpel, for example) to cut through tissue . Possible advantages here are tissue-saving use, synchronous obliteration of blood vessels and higher accuracy.

Physical basics

Laser beams correspond to electromagnetic waves which differ from conventional light in their high intensity, a limited frequency range, the possibility of sharp focusing and a long coherence length . According to the principle of stimulated emission , the beams are generated in a laser generator as optical amplification in resonant feedback . There are solid-state lasers , semiconductor lasers, dye lasers and gas lasers .

history

The first medical applications of lasers took place immediately after their invention in 1960 in the field of ophthalmology . In the next few years, other areas were opened up.

application areas

Eye surgery

  • Different types of lasers are used to treat refractive errors. In laser eye surgery, a knife is used to partially loosen the cornea of ​​the eye. Refractory errors can then be corrected with the laser. Photoreactive keratectomy removes opacities and surface defects from the cornea . Vessels are cauterized using laser coagulation . Lasers can also be used to treat tears in the retina .

Vascular surgery, urology, endoscopic use

  • In various branches of medicine, the laser is also used to remove benign and malignant lesions . Here, for example, tumors in the bronchi can be removed with the laser and the airways can be reopened. In addition, the high energy of the laser can occlude the blood vessel in a wide variety of bleeding sources ( endobronchial , endoesophageal) .

Thoracic surgery

  • The main area of application of the laser in thoracic surgery is the tissue-friendly removal of lung metastases from tumors of various primary locations. Other possible uses are parenchymal transection in anatomical segment resections, removal of tumors from the chest wall and abrasion of the parietal pleura.

Metastasis surgery

  • Indication: The lungs are one of the most common organs into which tumors in other primary locations can metastasize . Various studies have shown that the removal of these metastases has a positive prognostic value for selected patients. Guiding principles are survival extension and potential healing. In addition, the resection of lung metastases to obtain histology (for example for a new receptor determination in the context of breast cancer ) is of great importance. Ultimately, there are various tumor entities that do not respond to any other (e.g. systemic chemo) therapy , so that removal using laser surgery is the only remaining option. In the case of multiple round nodules in particular, the loss of normal lung tissue with other resection methods (e.g. anatomical segment or flap resections, wedge resections using staple technology) would be very large. By using the laser , the metastases can be removed with a minimal loss of functional lung. The number of potentially resectable nodules has increased significantly as a result of laser technology. In addition, there is better postoperative lung function after laser surgery .
  • In contrast to ablative interventional radiology, in which lung metastases are destroyed by radiation or heat, laser surgery also offers the option of histological examination of the removed material.
  • Requirements:
    • The primary tumor (e.g. colon , breast or kidney cancer ) should be completely (curatively) treated or potentially removable. All pulmonary nodules visible on CT should be technically resectable. It could be shown that metastasis surgery only has a prognostic value if all metastases have been completely removed . If there are also metastases outside the chest , these should also be treatable in principle.
    • In addition, the patient must have a sufficiently good lung function that enables an operation with single-lung ventilation.

Diagnosis

Computed tomography of the thorax is essential for planning the location and number of metastases . This should not be older than 4-6 weeks for the operation to be performed. Other examinations (e.g. scintigraphy , abdominal CT, etc.) should exclude other tumor manifestations or assess them as curable in principle. In the case of certain types of tumor (e.g. breast cancer ), preoperative bronchoscopy can be useful to rule out mucosal metastases.

Ultimately, current lung function and stress tests must be available.

method

For the complete removal of all pulmonary nodules, a thoracotomy , i.e. an opening of the chest, is usually necessary. This is usually done on one side at first, but in principle metastases can also be removed on both sides at the same time. In the normal procedure, however, both lungs are operated on sequentially at intervals of approx. 6–8 weeks in the event of bilateral involvement .

The lungs are then palpated with the fingers so that all nodules can be identified corresponding to the previously made CT. Often there are other nodules and changes that are not visible in the imaging.

After identification, the nodules are then individually “cut out” of the normal lung parenchyma, whereby only a narrow border of healthy tissue has to be resected due to the precision of the laser . The resulting laser cavities in the lung tissue are then closed with dissolving threads.

In principle, round nodules in peripheral locations can also be removed using an endoscopic approach; experience in this technique is available in the relevant centers.

Another component of metastasis surgery via a thoracotomy is the simultaneous possibility of removing lymph nodes from the middle layer. The possible involvement of these lymph nodes can be another prognostic marker depending on the primary tumor location, but this is the subject of ongoing research and discussion.

Should metastases occur again on one or both sides after laser surgery , a new re-operation is in principle possible. Influencing factors for the renewed decision to operate are again the lung function and the time interval or general disease progression. For z. B. colorectal cancer , however, prolonged survival times could be found by repeated metastasis resections.

Required safety measures in medical use

When using a laser device in the operating room, certain safety measures must be observed. Some of these are regulated by law and relate to patient and employee safety.

  1. Warning notices at the entrance to the operating room, illuminated when the system is started up
  2. Protection of the patient's eyes with protective caps (anesthesia)
  3. Protection of the employee's eyes with protective goggles adapted to the laser spectrum (with additional side protection)
  4. Avoiding reflective surfaces in the room

Individual evidence

  1. ↑ Rolle A, Thetter O, Häussinger K et al .: Use of the Nd: YAG laser in thoracic surgery. In: Heart Vascular Thorax Chir . tape 3 , 1989, pp. 85-91 .
  2. ↑ Inderbitzi R, Rolle A .: Palliative surgery for primary and secondary thoracic malignancies. Ed .: Ther Umsch. tape 58 , no. 7 , 2001, p. 435-41 .
  3. ↑ Pastorino U, Friedel G, Buyse M et al .: Long-term results of lung metastasectomy: prognostic analyzes based on 5,206 cases. Ed .: J Thorac Cardiovasc Surg. tape 113 , 1997, pp. 37-49 .
  4. ↑ Kolyadina IV Andreeva YY, Frank GA et al .: Role of biological heterogeneity in recurrent and metastatic breast cancer. In: Arkh Patol. tape 80 , no. 6 , 2018, p. 62-67 .
  5. ↑ Mineo TC, Cristino B, Ambrogi V et al .: Usefulness of the Nd: YAG laser in parenchyma-sparing resection of pulmonary nodular lesions. In: Tumori . tape 80 , no. 5 , 1994, pp. 365-369 .
  6. ↑ Rolle A, Pereszlenyi A, Koch R et al .: Is surgery for multiple lung metastases reasonable? A total of 328 consecutive patients with multiple-laser metastasectomies with a new 1318-nm Nd: YAG laser. In: J Thorac Cardiovasc Surg . tape 131 , no. 6 , 2006, p. 1236-1242 .
  7. ↑ Riquet M, Foucault C, Cazes A et al .: Pulmonary resection for metastases of colorectal adenocarcinoma. In: Ann Thorac Surg . tape 89 , no. 375-380 , 2010.
  8. ↑ Detterbeck FC, Grodzki T, Gleeson F et al .: Imaging Requirements in the Practice of Pulmonary Metastasectomy. In: J Thorac Oncol . tape 5 , 2010, p. 134-139 .
  9. ↑ Marchioni A, Lasagni A, Busca A .: Endobronchial metastasis: an epidemiologic and clinicopathologic study of 174 consecutive cases. In: Lung Cancer . tape 84 , no. 3 , 2014, p. 222-8 .
  10. ↑ Brunelli A, Charloux A, Bolliger CT et al .: RS / ESTS clinical guidelines on fitness for radical therapy in lung cancer patients (surgery and chemoradiotherapy). In: Eur Respir J . tape 34 , 2009, p. 17-41 .
  11. ↑ Cerfolio RJ, McCarty T, Bryant AS: Non-imaged pulmonary nodules discovered during thoracotomy for lung metastasectomy by palpation. In: EUR J Cardiothorac Surg . tape 35 , no. 5 , 2009, p. 786-791 .
  12. ↑ García-Yuste M, Cassivi S, Paleru C .: Thoracic lymphatic involvement in patients having pulmonary metastasectomy. In: J Thorac Oncol . tape 5 , no. 2 , 2010, p. 166-169 .
  13. ↑ Jaklitsch MT, Mery CM, Lukanich JM et al .: equential thoracic metastasectomy prolongs survival by re-establishing local control within the chest. In: J Thorac Cardiovasc Surg . tape 121 , 2001, p. 657-67 .