Background & Aims
Quantitative sensory testing (QST) provides an assessment of cutaneous and deep tissue sensitivity and pain perception under normal and pathological settings [1]. Approximately 3-9% of individuals undergoing groin hernia repair develop persistent post-surgical pain (PPSP) [2], and 2-4% develop severe PPSP [3]. The aims of this systematic review of PPSP patients were (1) to retrieve and methodologically characterize the available QST literature and (2) to explore the role of QST in understanding mechanisms underlying PPSP following groin hernia repair.
Methods
A systematic literature search was conducted from JAN-1992 to SEP-2022 in PubMed, EMBASE, and Google Scholar. For inclusion, studies had to report at least one QST modality in patients with PPSP. Risk of bias assessment of the studies was conducted utilizing the Newcastle Ottawa Scale and Cochrane’s Risk of Bias assessment tool 2.0. The review provided both qualitative and quantitative analyses of the results. A random effects model was used for meta-analysis.
Results
Twenty-five studies were included (5 randomized controlled trials and 20 non-randomized controlled trials). Overall, the risk of bias was low. Compared with the contralateral side or controls, there were significant alterations in the somatosensory function of the surgical site in PPSP patients. Following thresholds were significantly increased: mechanical detection thresholds for punctate stimuli (mean difference (95% CI) 3.3 (1.6, 6.9) mN (P = 0.002)), warmth detection thresholds (3.2 (1.6, 4.7) °C (P = 0.0001)), cool detection thresholds (-3.2 (-4.9, -1.6) °C (P = 0.0001)), and heat pain thresholds (1.9 (1.1, 2.7) °C (P = 0.00001)). However, the pressure pain thresholds were significantly decreased (-76 (-123, -30) kPa (P = 0.001)).
Conclusions
Our review demonstrates a plethora of methods used regarding outcome assessments, data processing, and data interpretation. From a pathophysiological perspective, the most consistent findings were post-surgical cutaneous deafferentation and the development of a pain generator in the deeper connective tissues [4].
References
[1] Mücke M, Cuhls H, Radbruch L, Baron R, Maier C, Tölle T, et al.979 Quantitative sensory testing (QST). English version. Schmerz. 2021;35(Suppl
980 3):153-60.
[2] Aiolfi A, Cavalli M, Ferraro SD, Manfredini L, Bonitta G, Bruni PG, et al. Treatment of Inguinal Hernia: Systematic Review and Updated Network Meta-analysis of Randomized Controlled Trials. Ann Surg. 2021;274(6):954-61.
[3] Jensen EK, Ringsted TK, Bischoff JM, Petersen MA, Rosenberg J, Kehlet H, Werner MU. A national center for persistent severe pain after groin hernia repair: Five-year prospective data. Medicine (Baltimore). 2019;98(33):e16600. doi: 10.1097/MD.0000000000016600 [doi];00005792-201908160-00005 [pii].
[4] Jensen EK, Ringsted TK, Bischoff JM, Petersen MA, Møller K, Kehlet H, Werner MU. Somatosensory Outcomes Following Re-Surgery in Persistent Severe Pain After Groin Hernia Repair: A Prospective Observational Study. J Pain Res. 2023;16:943-59. Epub 2023/03/25. doi: 10.2147/jpr.S384973. PubMed PMID: 36960467; PubMed Central PMCID: PMCPMC10030060.
Presenting Author
Mads U. Werner
Poster Authors
Mads U Werner, MD, PhD
M.D., Ph.D., D.M.Sc.
DanTrials, Zelo Phase 1 Unit, Copenhagen University Hospitals–Bispebjerg Hospital, Denmark
Lead Author
Akhmedkhan Dubayev
M.D.
Neuroscience Center, Copenhagen University Hospitals - Rigshospitalet, DENMARK
Lead Author
Elisabeth K. Jensen
Neuroscience Center, Copenhagen University Hospitals - Rigshospitalet, DENMARK
Lead Author
Kenneth G. Andersen
M.D.
Department of Anesthesia, Copenhagen University Hospitals - Hvidovre Hospital, DENMARK
Lead Author
Martin F. Bjurström
M.D.
Department of Surgical Sciences, Uppsala University, Uppsala, SWEDEN
Lead Author
Topics
- Systematic Reviews/Meta-Analysis