1. Thoracic epidural anesthesia in major vascular surgery and antiplatelet drugs
Gramaglia L., Renghi A., Cassatella R., Martelli M., Brustia P.
Novara University Hospital – Novara - Italy
Introduction
Results
Thoracic epidural anesthesia/analgesia (TEA) is known as most effective technique for postoperative pain management, improving surgical outcomes especially in fast track surgery (1). Nevertheless this technique used for patients with antiplatelet drugs scheduled to systemic intraoperative heparin, as aortic surgery, may leave some perplexity. Anyway antiplatelet drug suspension increases cardiac and embolic risks so much that guidelines counsel risks/benefit balance for every clinical case (2).
The Vascular Team treated 917 patients for non emergent/urgent aortic pathologies, 802 in OAR and 115 in TEVAR/EVAR. We excluded 44 patients (40 in open group and 4 in endovascular group) because under anticoagulant therapy, therefore not pertaining to this work. About OAR group in 30 patients epidural catheter wasn't inserted because related to another double blinded study as well as in 5 due to preoperative considerable clinical coagulopathies. About TEVAR/EVAR group 100 patients were treated with lumbar spinal or general anesthesia. A total of 738 patients were managed with TEA: 86 of them weren't under antiplatelet therapy; 531 were under Aspirin; 4 Aspirin and Dipirydamol; 7 only Dipirydamol; 91 Thienopyridines (Ticlopidin or Clopidogrel) and 19 double antiplatelet therapy (Aspirin and Thienopyridine) following cardiologist consultant (see Table 1). In the last subgroup only 5 discontinued one of two antiplatelet drugs after risk/benefit evaluation by vascular team. Finally we checked all possible adverse events, specially neurological one, and we found: 1 epidural lumbar hematoma where cerebrospinal fluid (CSF) drainage was inserted for TEVAR, but not where thoracic epidural catheter was located; 1 lower limbs hyposthenia as vascular complication; 1 stellate ganglion blockade; 1 inadequate epidural analgesia and 1 catheter removal after 72 hours due to postoperative deficit of platelets. About mortality and morbidity we have had 13 deaths: 3 due to cardiac events; 3 due to postoperative intestinal ischemia (1 patient was under double antiplatelet therapy); 1 due to severe rhabdomyolysis; 1 for severe bleeding after prosthesis detachment (patient under Aspirin 100 mg) and 5 after multiple organ failure (see Table 3). All patients were awakened in operative room at the end of surgery except for 5 patients, admitted in intensive care unit (two of them died). 4 patients were admitted to intensive care unit in postoperative 2th-4th day and all died. We have had 8 hospital re-admittance in postoperative 30th day for adverse events epidural catheter not-correlated.
Methods and Materials
A retrospective study was performed analyzing patients scheduled to open, abdominal and thoracic endovascular aortic repair (OAR, TEVAR and EVAR respectively) since May 2000 to May 2011 by Vascular Unit of Novara University Hospital. The patients were treated with perioperative TEA. Patients in emergency/urgency, those operated without neuraxial blockade and those under anticoagulant therapy were excluded. Since 2000 our behavior to antiplatelet therapy management was always of one, following a guideline founded on international literature and shared by anesthesiologists, surgeons and cardiologists. The single assumption of Acetylsalicylic Acid (Aspirin) or Thienopyridines (for patients allergic to aspirin) wasn’t stopped, unless preoperative exams emphasized clinical coagulation disorders. About patients with double antiplatelet therapy, every clinical case was evaluated by anesthesiologists, surgeons and cardiologists, balancing risks/benefits related to suspension of one antiplatelet drug and use of epidural catheter. The team agreed to surgical disruption if bleeding were seen after epidural catheter insertion and to the administration of intraoperative intravenous heparin one hour after epidural procedure. Morphine 0,1 mg/kg was administered to patients scheduled to OAR 2 hours before surgery. Epidural catheter 19 G size was inserted through Tuohy 17 G needle at T6-T7 or T7-T8 level. Thereafter Levobupivacaine 0,5% ml were administered within 30 minutes obtaining sensitive blockade between T4 and S2. After induction with Propofol 1 mg/kg, a Laryngeal Mask was inserted maintaining light general anesthesia with Sevoflurane 0,6-0,7 MAC and spontaneous breathing when possible. Intraoperative epidural infusion with Levobupivacaine 0,5% 4-5 ml/h was performed. At the end of surgery patients were awakened and carried to vascular ward. Postoperative epidural analgesia was continued with Levobupivacaine 0,25% 3-6 ml/h, associated to Ibuprofen 600 mg orally every 8 hours. Epidural infusion of opioids was avoided.
Discharge
Median (range) days
Mean (± sd) days
All patients
3 (1-74)
4.04 (± 3.68)
OAR
4.03 (± 3.69)
EVAR / TEVAR
4 (2-13)
4.82 (± 3.55)
Table 2: discharge from vascular ward (day of surgery excluded)
Discussion & Conclusions
TEA in major surgery shows many advantages compared with other perioperative analgesic techniques. This approach modulates surgical stress, improves respiratory functionality, hemodynamic stability and decreases the prothrombotic response. In aortic surgery lower cardiac accidents, better pulmonary function, renal protection and lower ileus were shown. TEA associated to fast-track protocol decreases postoperative length of stay and morbidity as pointed out by European and American guidelines for aortic surgery management (2) (see Table 2). Even so the epidural technique has infrequent but potentially serious risks, specially in patient under antiplatelet therapy and intraoperative heparin. Nowadays several guidelines don’t proscribe TEA with Aspirin, but question about Thienopyridines and double antiplatelet therapy (3). In many works the authors encourage to evaluate risk/benefit balance for every clinical case. It’s known that antiplatelets suspension may be very dangerous for cardiac patients, notably those with coronary stenting (4). In our 11 years experience we treated 90% of patients under antipleatelets and we haven’t TEA severe adverse events, excepted one related to lumbar CSF drainage in TEVAR, which position is justified by high risk of perioperative paraplegia (30%).
The review of our database sustains the safety of this technique in vascular surgery and we can suppose that TEA without antiplatelets suspension may contribute to decrease cardiovascular ischemic accidents and improve fast-track program, decreasing perioperative morbidity.
Antiplatelet drugs
Patients number %
None 86
11,6
Aspirin
531
71,9
Aspirin + Dipirydamol 4
0,5
Thienopyridines ( Ticlopidin or Clopidogrel) 91
12,3
Dipirydamol 7
0,9
Double (Aspirin + Thienopyridine) 19
2,5
All patients
738
100
Table 1: antiplatelet therapy
Sedation for patients scheduled to endovascular procedures was the same as seen above and spinal anesthesia was performed at L2-L3 level or general anesthesia and Laryngeal Mask as alternative. Epidural catheter at T9-T10 level was allowed only for TEVAR or long and complex procedures. According to surgeons intraoperative heparin was antagonized by adequate quantity of Protamine Sulfate before end of surgery. In postoperative care we applied fast-track protocol to all patients as follows: early oral intake, early oral therapy (antiplatelet drugs included) and early assisted deambulation few hours after surgery, so that they didn't need heparin prophylaxis. Epidural catheter was removed 48 hours after surgery. The ward nurses were trained to analgesia management, hemodynamic monitoring and neurological surveillance. In this work we studied the following parameters: surgery and anesthesiological techniques, current antiplatelet drugs therapy, hemorrhagic and neuraxial major adverse events, early postoperative and one month after mortality and morbidity outcomes.
Postoperative adverse events
Patients number %
Cardiac accidents 11
1,49
Transient serum creatinine increase 13
1,76
Peripheral embolization 15
2,03
Intestinal ischemia 3
0,40
Mortality
References
Table 3: morbidity and mortality in 738 patients
(1) Clemente A, Carli F. The physiological effects of thoracic epiduralanesthesia and analgesia on the cardiovascular, respiratory and gastrointestinal systems. Minerva Anestesiol. 2008; 74:
(2) Moll FL et Al. Management of Abdominal Aortic Aneurysms Clinical Practice Guidelines of the European Society for Vascular Surgery. Eur J Endovasc Surg 2011; 41: S1-S58
(3) Gogarten W et Al. Regional anaesthesia and antithrombotic agents: Recommendations of the European Society of Anaesthesiology Eur J Anaesthesiol 2010 Dec 27(12):
(4) Fleisher LA et Al. ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2007 Oct 23;116(17):e418-99