Seoul National University Bundang Hospital (SNUBH) said that it has confirmed the efficacy and safety of a new pain treatment method that can effectively manage postoperative pain in patients undergoing lung resection with video-assisted thoracoscopic surgery (VATS).

The research team -- led by Jeon Jae-hyun, Professor of Thoracic and Cardiovascular Surgery at SNUBH, Seong Yong-won, Professor of Thoracic and Cardiovascular Surgery at Seoul Metropolitan Government–Seoul National University (SMG-SNU) Boramae Medical Center, and Kim Kwhan-mien, Professor of Thoracic and Cardiovascular Surgery at SNUBH -- demonstrated the effectiveness and safety of a new pain management method that combines a thermosensitive hydrogel with a local anesthetic.

Thoracoscopic surgery is performed by inserting instruments through several small holes of about 1cm to 2cm. The incision is smaller than a thoracotomy, which involves making an incision in the chest and spreading the ribs apart to fit the surgeon's hand. For this reason, thoracoscopy is commonly used because it is less painful, faster to recover, and has fewer complications.

However, when a thoracoscopy is used to remove a lung, it still stimulates a dense network of nerves located near the ribs, causing persistent pain that can make breathing and coughing difficult.

Poorly managed pain can lead to a variety of cardiopulmonary complications, so effective treatment for perioperative pain, especially acute postoperative pain, is crucial.

The traditional method has been performed by administering local anesthetics through a thin catheter inserted into the surgical site. However, this method cannot be used in cases where the pleura, the thin membrane surrounding the lungs, is too adherent to allow room for the catheter to be inserted, leading to bleeding complications and possible drug leakage into the wound.

In addition, it takes a lot of time to prepare and causes inconvenience to the patient, demanding a need to develop an effective local anesthetic that can be easily applied in the medical field.

In this study, the researchers randomized a total of 90 patients undergoing thoracoscopic lung resection (45 in the experimental group and 45 in the control group). Poloxamer 407, A gel based on a thermosensitive polymer, mixed with local anesthetic was applied as an injection to patients undergoing thoracoscopic surgery, compared to a control group administered by catheterization in terms of local anesthetic use, comparing the use of fentanyl, a narcotic painkiller, and dependence on Demerol, a narcotic painkiller.

Poloxamer 407, which was approved by the FDA, is characterized by temperature-dependent properties that allow it to be easily injected at room temperature, and to turn into a viscous gel at body temperature. When applied to the surgical incision, the drug is released gradually over 72 hours.

The researchers found that the amount of local anesthetic used was about one-eighth less than the control group. In addition, fentanyl use and Demerol dependence were similar in the 72 hours after surgery between two arms.

"The newly developed pain treatment method is a breakthrough result that can be effectively applied to patients undergoing thoracoscopic lung resection, allowing them to be comfortable after surgery and focus on their recovery," Professor Kim said.

"While results may vary slightly depending on the site and method of application, this treatment method could be a simple way for patients to recover from their postoperative pain," Professor Jeon added.

The study, titled "Randomized Trial of Poloxamer 407-Based Ropivacaine Hydrogel After Thoracoscopic Pulmonary Resection," was published in the latest issue of the Annals of Thoracic Surgery, a world-renowned journal published by the American Society of Thoracic Surgeons, and was presented at the Korean Society for Thoracic & Cardiovascular Surgery Fall Meeting & Asia-Pacific ELSO (APELSO) on November 2, 2023.