Pectoral nerve blocks type II anesthesia for vascular port implantation

Brief name: PECS II nerve block for venous access port implantation: retrospective and observational study. Due to the observational and retrospective type of the study, all participants received these interventions regardless of their involvement in this study, and the data were taken from patients undergoing PECS II procedure for venous access port implantation from 1st Jan 2019 to 31st Dec 2020. Venous access port implantation procedures are performed mainly by venipuncture of the right or left internal jugular vein, inserting a catheter into the superior vena cava, at the junction of the vein and the right atrium. The catheter is then tunnelled and connected to a port chamber implanted into the subcutaneous pocket in the ipsilateral subclavian region. Venous access port implantation can also be done by venesection, inserting a catheter into one of the veins in the arm in the area of the deltoid-thoracic sulcus. In most cases, it is the cephalic vein. The port chamber is implanted into a subcutaneous pocket created in the ipsilateral subclavian region. This method eliminates the need for catheter tunnelling. A venous access port catheter can also be implanted by performing subclavian vein venipuncture. Regardless of the technique, venous access port implantation procedures are performed under local infiltration anaesthesia, using a large volume of anaesthetic with adrenaline (about 30-40ml). Pectoral Nerve Blocks type I and II (PECS I and II) are nerve blocks in the chest wall, an alternative to paravertebral block (PVB), commonly used as one of the elements of multimodal analgesia in thoracic procedures (mainly breast surgery). PECS I is a nerve block, in which a local anaesthetic is deposited in the plane between the pectoralis major and the pectoralis minor, at the level of the third rib, blocking the lateral and medial pectoral nerves. PECS I can be used for procedures in the chest wall, drainage of the pleural cavity or for procedures limited to the pectoralis major muscle. PECS II is a modification of the PECS I block, in which, after the deposition of the anaesthetic in the plane between the pectoral muscles, an additional dose of a local anaesthetic is administered between the pectoralis minor and the anterior dentate muscle, blocking the lateral branches of the T2 to T4 intercostal nerves, the intercostal-brachial nerve and the long thoracic nerve. PECS II can be used for the procedures described above as well as for more extensive breast surgery procedures (mastectomy, quadrantectomy). Then it is performed more laterally than the PECS I block (usually in the anterior axillary line). The ultrasound technique is used to identify the fascial spaces, with a linear probe (5-12 MHz). After the fascial spaces are identified, a 45 degree angle needle is inserted into them and a local anaesthetic is administered under the ultrasound guidance. The aim of the study was to assess the effectiveness of PECS II block in anaesthesia for venous access port implantation through the cephalic vein venesection method, considering the volume of the local anaesthetic used and the comfort of the patient and the operator. All the patients enrolled in the study were scheduled to undergo venous access port implantation by the cephalic vein venesection in the area of the deltoid-thoracic sulcus on the right or left side of the chest. The right side is the default side in order to shorten the length of the catheter. Port implantation is planned on the left side in the case of contraindications to implantation on the right side. Neither pharmacological premedication nor analgosedation was planned during the procedure. The implantation procedure was performed in a modified PECS II block by administering an anaesthetic under the ultrasound guidance between the fascia of the pectoralis major and the pectoralis minor, and between the fascia of the pectoralis minor and the dentate muscle, identifying the fascial structures more medially than in the classic method, i.e. around the mid-clavicular line. The intended volume of the anaesthetic (from 15-20 ml) was evenly deposited between the two compartments. Venus access port implantation began with aseptic preparation of the surgical field. Just below the clavicle, the muscle groups were located with the help of an ultrasound head. After the structures had been identified under the ultrasound guidance, using an in-plane technique, a lead needle with a 22-gauge diameter and a length of 50mm was inserted parallel to the clavicle towards the head of the humerus at an angle of 30-45 degrees. After confirming that the intended space had been reached, 8-10 ml of the anaesthetic was deposited in a volume sufficient to dissect the fascia laminae to a width of minimum 4 cm, thus anaesthetising the neurovascular structures located there. The deeper structures were then anaesthetised with the same volume of the analgesic. In the venesection of the vein in the deltoid-thoracic sulcus, it is necessary to anaesthetise the deeper anatomical structures, which is why PECS type II method was selected. Due to the insufficient anaesthesia of the skin, frequently occurring with PECS II, before the incision infiltration anaesthesia of the incision line was performed, with the use of 0.5% lignocaine with 0.005% adrenaline in a volume of 3 ml. Subsequently, in the deltoid-thoracic groove, the cephalic vein venesection was performed and, under fluoroscopy, a vascular catheter was inserted into the vein, with its tip placed into the superior vena cava at the junction with the right atrium. Then the catheter was connected with the port chamber implanted into the created subcutaneous pocket of the pectoralis major fascia. The above-mentioned procedures were performed by the following persons: an anaesthesiology and intensive care specialist with extensive experience of venous access port implantation and a resident doctor in the fourth year of training in anaesthesiology and intensive care under the supervision of the specialist doctor, with basic skills in the field of venous access port implementation and three years of experience in performing regional blocks. During a postoperative examination connected with the removal of sutures on day 8 after the procedure or flushing the port before starting the scheduled chemotherapy, the patients were asked by a nurse about the pain intensity 24 hours after the procedure, the satisfaction assessment by means of the QoR-15 score or about the occurrence of side effects. Early complications are defined as occurring up to 7 days after the procedure. The operator’s comfort was assessed on a 3-point scale created by the operators (Operator's Condition Assessment Score), considering the duration of the procedure, cooperation with the patient/ stability of the surgical field, the presence of pain complaints during the procedure and the related necessity to give local anaesthetic intraoperatively. The responses were rated on a scale of 0-2, with 0 meaning a good operator rating, 1 an acceptable rating and 2 a rating difficult to accept. The research protocol included age, sex, body weight, body height, BMI, the volume of local anaesthetic used, duration of anaesthesia and the procedure, preoperative ASA assessment, a technique used to perform the procedure, patient’s NRS assessment at measurement points, the result of the operator’s comfort assessment on the Operator’s Condition Assessment scale.