Successful local anesthesia is required for control of pain during dental procedures. Anesthesia should also occur with a low rate of additional complications, such as positive aspiration, swelling and so on. The inferior alveolar nerve block is the most commonly used block during oral surgery. However, this block has a comparatively high failure rate29, mainly because of inter-patient anatomic variations. Therefore, various other nerve blocks were utilized over time to improve the success rate of anesthesia. The G-G and V-A methods discussed in this paper have been the most important alternatives. They differ from the conventional IANB technique in terms of the location of the injection point. From the analysis of the RCTs included above, it can be concluded that G-G and V-A techniques enjoy several advantages over IANB techniques when utilized during mandibular third molar extraction. The results suggest that they may be a useful alternative to IANB with regard to an increase in anesthetic success and a decrease in clinically dangerous positive aspiration.
Some studies even suggest that these alternative techniques may decrease the incidence of certain complications such as swelling and pain in the injection area. With respect to these ancillary advantages of the alternative techniques, however, not enough research has been done to conclude via meta-analysis that G-G or V-A can de facto reduce such complications.
The meta-analysis has, however, uncovered one enigma: the analgesic onset time of both G-G and V-A is longer than of IANB. The reasons for this are not clear. But because they differ from the IANB technique principally in terms of the location of various injection points, one could hypothesize that a slower onset time might be a result of different anatomic factors associated with different injection areas. Among these factors could be differences in nerve distribution, in blood flow condition, or even in soft tissue conditions associated with distinct injection areas.
In IANB the anesthetic is injected in the pterygo-submandibular space, the posterior boundary of which is the parotid gland, exterior the ramus of the mandible, interior and inferior the medial pterygoid, superior the external pterygoid, and anterior the masseter. The G-G method consists somewhat of a type of “high” inferior alveolar nerve block anesthesia, whose anesthetic is injected principally at the mandibular condylar region. In the V-A approach, the anesthetic is injected into the upper part of the pterygo-mandibular space, so that the three branches of the mandibular nerve (the inferior alveolar, lingual and buccal nerves) are anesthetized.
It should also be pointed out that, due to various confounding variables, such as types and concentrations of anesthetic substances adopted in these seven RCTs, as well as differential levels of experience on the part of those administering the anesthesia, it is not possible to formulate absolute conclusions concerning their properties of onset time, success rate and positive aspiration rate. Four of the studies used lidocaine, one adopted articaine and two did not describe the drug type. ALLEN L 1896 conducted local anesthesia with administration of 8 ml 2% lidocaine in V-A while using 2.3 ml in the IANB group. Fei Wang 2002 utilized 3 ml 2% lidocaine in both the IANB and the G-G groups. Jieping Yang 2013 utilized 3–5 ml 2% lidocaine in both the IANB and the G-G groups. Jiacai He 2000 used 2 ml 2% lidocaine in both IANB and V-A. Martinez, G 2003 used 1.8 ml 4% articaine in both IANB and V-A. Jizhong Lv 2009 and Diandian Li 2009 did not provide specific details about anesthetic types and concentrations in each group. Apart from these variations among the studies, the issue of different concentrations of epinephrine also arises. Martinez, G 2003 ALLEN L 1896 and Jieping Yang 2013 adopted a 1:100,000 concentration of epinephrine. Jiacai He 2000 also added an unspecified amount epinephrine in the anesthesia. The remaining three RCTs had no information on this matter. It is true that previous research showed that the concentration of epinephrine does not influence the anesthetic success rate of IANB30. However, there is not enough evidences to indicate whether epinephrine concentration will affect the anesthetic effectiveness and safety of the G-G and V-A methods. Variations in these factors might lead to a higher index of heterogeneity, which could arguably weaken the results of this meta-analysis.
Despite the presence of these limitations, however, this meta-analysis has successfully compared intervention and control techniques under similar conditions. It seemed both logical and valid to pool together data from these studies. On the other hand, further studies should be undertaken that would take into consideration variables such as anesthetic and epinephrine types and concentrations to verify these findings.
1. Kehlet H, White PF. Optimizing anesthesia for inguinal herniorrhaphy: General, regional, or local anesthesia? Anesth Analg. 2001;93:1367–9.[PubMed]
2. van Vlymen JM, White PF. Fast-track concept for ambulatory anesthesia. Curr Opin Anaesthesiol. 1998;11:607–13.[PubMed]
3. Akcaboy EY, Akcaboy ZN, Gogus N. Ambulatory inguinal herniorrhaphy: Paravertebral block versus spinal anesthesia. Minerva Anestesiol. 2009;75:684–91.[PubMed]
4. Mishra M, Mishra SP, Singh SP. Comparison of spinal with paravertebral block for elective open inguinal hernia repair. World J Med Res. 2016;5:1–6.
5. Chung F, Ritchie E, Su J. Postoperative pain in ambulatory surgery. Anesth Analg. 1997;85:808–16.[PubMed]
6. Pavlin DJ, Rapp SE, Polissar NL, Malmgren JA, Koerschgen M, Keyes H. Factors affecting discharge time in adult outpatients. Anesth Analg. 1998;87:816–26.[PubMed]
7. Junger A, Klasen J, Benson M, Sciuk G, Hartmann B, Sticher J, et al. Factors determining length of stay of surgical day-case patients. Eur J Anaesthesiol. 2001;18:314–21.[PubMed]
8. Burney RE, Prabhu MA, Greenfield ML, Shanks A, O’Reilly M. Comparison of spinal vs. general anesthesia via laryngeal mask airway in inguinal hernia repair. Arch Surg. 2004;139:183–7.[PubMed]
9. Hadzic A, Kerimoglu B, Loreio D, Karaca PE, Claudio RE, Yufa M, et al. Paravertebral blocks provide superior same-day recovery over general anesthesia for patients undergoing inguinal hernia repair. Anesth Analg. 2006;102:1076–81.[PubMed]
10. Klein SM, Greengrass RA, Weltz C, Warner DS. Paravertebral somatic nerve block for outpatient inguinal herniorrhaphy: An expanded case report of 22 patients. Reg Anesth Pain Med. 1998;23:306–10.[PubMed]
11. Klein SM, Pietrobon R, Nielsen KC, Steele SM, Warner DS, Moylan JA, et al. Paravertebral somatic nerve block compared with peripheral nerve blocks for outpatient inguinal herniorrhaphy. Reg Anesth Pain Med. 2002;27:476–80.[PubMed]
12. Kehlet H, Dahl JB. Spinal anaesthesia for inguinal hernia repair? Acta Anaesthesiol Scand. 2003;47:1–2.[PubMed]
13. Yilmazlar A, Bilgel H, Donmez C, Guney A, Yilmazlar T, Tokat O. Comparison of ilioinguinal-iliohypogastric nerve block versus spinal anesthesia for inguinal herniorrhaphy. South Med J. 2006;99:48–51.[PubMed]
14. White PF. Choice of peripheral nerve block for inguinal herniorrhaphy: Is better the enemy of good? Anesth Analg. 2006;102:1073–5.[PubMed]
15. Law LS, Tan M, Bai Y, Miller TE, Li YJ, Gan TJ. Paravertebral block for inguinal herniorrhaphy: A systematic review and meta-analysis of randomized controlled trials. Anesth Analg. 2015;121:556–69.[PubMed]
16. Naja ZM, Raf M, El Rajab M, Ziade FM, Al Tannir MA, Lönnqvist PA. Nerve stimulator-guided paravertebral blockade combined with sevoflurane sedation versus general anesthesia with systemic analgesia for postherniorrhaphy pain relief in children: A prospective randomized trial. Anesthesiology. 2005;103:600–5.[PubMed]
17. White PF, Song D. New criteria for fast-tracking after outpatient anesthesia: A comparison with the modified Aldrete's scoring system. Anesth Analg. 1999;88:1069–72.[PubMed]
18. Williams BA. For outpatients, does regional anesthesia truly shorten the hospital stay, and how should we define postanesthesia care unit bypass eligibility? Anesthesiology. 2004;101:3–6.[PubMed]
19. Sinha SK, Brahmchari Y, Kaur M, Jain A. The comparative evaluation of safety and efficacy of unilateral paravertebral block with conventional spinal anaesthesia for inguinal hernia repair. Indian J Anaesth. 2016;60:499–505.[PMC free article][PubMed]
20. Isil CT, Çinar AS, Oba S, Isil RG. Comparison of spinal anaesthesia and paravertebral block in unilateral inguinal hernia repair. Turk J Anaesthesiol Reanim. 2014;42:257–63.[PMC free article][PubMed]
21. Fusco P, Cofini V, Petrucci E, Scimia P, Paladini G, Behr AU, et al. Unilateral paravertebral block compared with subarachnoid anesthesia for the management of postoperative pain syndrome after inguinal herniorrhaphy: A randomized controlled clinical trial. Pain. 2016;157:1105–13.[PubMed]
22. Mandal MC, Das S, Gupta S, Ghosh TR, Basu SR. Paravertebral block can be an alternative to unilateral spinal anaesthesia for inguinal hernia repair. Indian J Anaesth. 2011;55:584–9.[PMC free article][PubMed]
23. Bhattacharya P, Mandal MC, Mukhopadhyay S, Das S, Pal PP, Basu SR. Unilateral paravertebral block: An alternative to conventional spinal anaesthesia for inguinal hernia repair. Acta Anaesthesiol Scand. 2010;54:246–51.[PubMed]
24. Richardson J, Lönnqvist PA. Thoracic paravertebral block. Br J Anaesth. 1998;81:230–8.[PubMed]
25. Weltz CR, Greengrass RA, Lyerly HK. Ambulatory surgical management of breast carcinoma using paravertebral block. Ann Surg. 1995;222:19–26.[PubMed]
26. Lönnqvist PA, MacKenzie J, Soni AK, Conacher ID. Paravertebral blockade. Failure rate and complications. Anaesthesia. 1995;50:813–5.[PubMed]