Invited commentary: Persistent pain after inguinal hernia repair: what do we know and what do we need to know?

Athletes treated for inguinal-related groin pain by endoscopic totally extraperitoneal (TEP) repair: long-term benefits of a prospective cohort

PURPOSE

Inguinal-related groin pain (IRGP) in athletes is a multifactorial condition, posing a therapeutic challenge. If conservative treatment fails, totally extraperitoneal (TEP) repair is effective in pain relief. Because there are only few long-term follow-up results available, this study was designed to evaluate effectiveness of TEP repair in IRGP-patients years after the initial procedure.

METHODS

Patients enrolled in the original, prospective cohort study (TEP-ID-study) were subjected to two telephone questionnaires. The TEP-ID-study demonstrated favorable outcomes after TEP repair for IRGP-patients after a median follow-up of 19 months. The questionnaires in the current study assessed different aspects, including, but not limited to pain, recurrence, new groin-related symptoms and physical functioning measured by the Copenhagen Hip and Groin Outcome Score (HAGOS). The primary outcome was pain during exercise on the numeric rating scale (NRS) at very long-term follow-up.

RESULTS

Out of 32 male participants in the TEP-ID-study, 28 patients (88%) were available with a median follow-up of 83 months (range: 69-95). Seventy-five percent of athletes were pain free during exercise (p < 0.001). At 83 months follow-up, a median NRS of 0 was observed during exercise (IQR 0-2), which was significantly lower compared to earlier scores (p <0.01). Ten patients (36%) mentioned subjective recurrence of complaints, however, physical functioning improved on all HAGOS subscales (p <0.05).

CONCLUSION

This study demonstrates the safety and effectivity of TEP repair in a prospective cohort of IRGP-athletes, for whom conservative treatment had failed, with a follow-up period of over 80 months.

A Critical Appraisal of the Chronic Pain Rate After Inguinal Hernia Repair

Purpose: To critically appraise highly cited studies reporting on the rate of chronic pain after inguinal hernia repair. Methods: Google Scholar was searched on 23 May 2022. We only included publications with more than 10 citations per year since publication and more than 100 citations in total. Both reports of original data and systematic reviews were included. Risk of bias and quality of the included studies were assessed with either the Joanna Briggs Institute Checklist for Prevalence Studies or the AMSTAR 2 depending on study design. Results: Twenty studies were included and evaluated. The rate of chronic postoperative inguinal pain of any degree ranged from 10%-63%, and the rate of moderate-to-severe pain ranged from 1%-18%. All studies reported the rate of pain of any degree, and most studies reported the rate of moderate-to-severe pain influencing daily activities. Studies used different temporal definitions of chronic pain, but most studies defined it as pain persisting either three or six months postoperatively. Ten studies used unvalidated questionnaires or significantly modified versions of validated questionnaires. Eleven studies primarily included patients receiving open repair. Included studies had median 21 citations per year (range 10-39) and median 387 citations in total (range 127-788). Conclusion: The rates of chronic postoperative inguinal pain reported in the included highly cited studies are possibly inaccurate, excessive, and outdated. New prospective studies based on uniform definitions and standards of measurement are warranted to better assess a contemporary chronic pain rate after inguinal hernia repair.

Longitudinal cohort study on preoperative pain as a risk factor for chronic postoperative inguinal pain after groin hernia repair at 2-year follow-up

PURPOSE

To assess the rate of late chronic postoperative inguinal pain (CPIP) after groin hernia repair in patients with different categories of preoperative VRS (Verbal Rating Scale) pain and to make a pragmatic evaluation of the rates of potentially surgery-related CPIP vs. postoperative continuation of preexisting preoperative pain.

METHODS

Groin pain of patients operated from 01/11/2011 to 01/04/2014 was assessed preoperatively, postoperatively and at 2-year follow-up using a VRS-4 in 5670 consecutive groin hernia repairs. A PROM (Patient Related Outcomes Measurement) questionnaire studied the impact of CPIP on the patients' daily life.

RESULTS

Relevant (moderate or severe VRS) pain was registered preoperatively in 1639 of 5670 (29%) cases vs. 197 of 4704 (4.2%) cases at the 2-year follow-up. Among the latter, 125 (3.7%) cases were found in 3353 cases with no-relevant preoperative pain and 72 (5.3%) in 1351 cases with relevant preoperative pain. Relevant CPIP consisted of 179 (3.8%) cases of moderate pain and 18 (0.4%) cases of severe pain. The rate of severe CPIP was independent of the preoperative VRS-pain category while the rate of moderate CPIP (3.1%, 3.4%, 4.1%, 6.8%) increased in line with the preoperative (none, mild, moderate, and severe) VRS-pain categories. The VRS probably overestimated pain since 71.6% of the relevant CPIP patients assessed their pain as less bothersome than the hernia.

CONCLUSION

At the 2-year follow-up, relevant CPIP was registered in 4.2% cases, of which 63.5% were potentially surgery-related (no-relevant preoperative pain) and 36.5% possibly due to the postoperative persistence of preoperative pain. The rate of severe CPIP was constant around 0.4%.

Perioperative monitoring of inguinal hernia patients with a smartphone application

INTRODUCTION

Patient Reported Outcomes have become standard in the evaluation of inguinal hernia repair. However, the chosen outcomes remain heterogeneous and the measurements time-consuming or inadequate. Perioperative measurement of pain and recovery could benefit from the contemporary possibilities that mobile health applications offer.

METHODS

An application for smartphones and tablets was developed using the twitch crowdsourcing concept, classical questionnaires, experiences from randomised clinical trials, and patients' input.

RESULTS

Dichotomous questions and numeric rating scales, both pre- and post-operative, were implemented in the freely available Q1.6 application. Content, timing and frequencies were adapted to the inguinal hernia patient's daily life and assumed recovery. Certain combinations of answers were set as alert notifications to detect adverse events. Data are displayed on a web-based dashboard enabling real-time monitoring. Legal aspects were examined and taken into account.

DISCUSSION

The Q1.6 inguinal hernia app is an innovative tool for perioperative monitoring of pain and recovery of inguinal hernia patients. Previous limitations of classical measurements such as a large heterogeneity, retrospective data recording and different forms of bias can be eliminated. The `big data´ generated in this manner might be used for large-scale research to improve inguinal hernia surgery. The Q1.6 platform is not only hernia specific; it is also an innovative tool to measure PROs in any other domain.

A national center for persistent severe pain after groin hernia repair: Five-year prospective data

Severe persistent pain after groin hernia repair impairs quality-of-life. Prospective, consecutive cohort study including patients with pain-related impairment of physical and social life. Relevant surgical records were obtained, and examinations were by standardized clinical and neurophysiological tests. Patients demonstrating pain sensitivity to pressure algometry in the operated groin underwent re-surgery, while patients with neuropathic pain received pharmacotherapy. Questionnaires at baseline (Q0) and at the 5-year time point (Q5Y) were used in outcome analyses of pain intensity (numeric rating scale [NRS] 0-10) and pain-related effect on the activity-of-daily-living (Activities Assessment Scale [AAS]). Data are mean (95% CI).Analyses were made in 172/204 (84%) eligible patients. In 54/172 (31%) patients re-surgery (meshectomy/selective neurectomy) was performed, while the remaining 118/172 (69%) patients received pharmacotherapy. In the re-surgery group, activity-related, and average NRS-scores at Q0 were 6.6 (5.6-7.9) and 5.9 (5.6-5.9), respectively. Correspondingly, NRS-scores at Q5Y was 4.1 (3.3-5.1) and 3.1 (2.3-4.0; Q0 vs. Q5Y: P < .0005), respectively. Although both groups experienced a significant improvement in AAS-scores comparing Q0 vs. Q5Y (re-surgery group: 28% (4-43%; P < .0001); pharmacotherapy group: 5% (0-11%; P = .005)) the improvement was significantly larger in the re-surgery group (P = .02).This 5-year cohort study in patients with severe persistent pain after groin hernia repair signals that selection to re-surgery or pharmacotherapy, based on examination of pain sensitivity, is associated with significant improvement in outcome. Analyzing composite endpoints, combining pain and physical function, are novel in exploring interventional effects.ClinicalTrials.gov Identifier NCT03713047.

Surgical training in robotic surgery: surgical experience of robotic-assisted transabdominal preperitoneal inguinal herniorrhaphy with and without resident participation

Robotic-assisted surgery is becoming more popular in general surgery. Implementation of a robotic curriculum is necessary and will influence surgical training. The aim of this study is to compare surgical experience and outcomes with and without resident participation in robotic inguinal herniorrhaphy. A retrospective review of patients who underwent either unilateral or bilateral robotic-assisted transabdominal preperitoneal (TAPP) inguinal herniorrhaphy, with and without resident participation as console surgeons from January through December 2015, was performed. Patient demographics, procedure-related data, postoperative variables, and follow-up data were analyzed. A total of 104 patients were included. Patients were significantly older in the Resident group (57.5 ± 14.1 vs 50.6 ± 13.5 years, p = 0.01). Gender, BMI, and ASA classification were similar between groups. There were similar mean operative times for unilateral (89.9 ± 19.5 vs 84.8 ± 22.2 min, p = 0.42) and bilateral (128.4 ± 21.9 vs 129.8 ± 50.9 min, p = 0.90) inguinal herniorrhaphy as well as mean robot console times for unilateral (73.2 ± 18.4 vs 67.3 ± 29.9 min, p = 0.44) and bilateral (115.5 ± 24.6 vs 109.3 ± 55.4 min, p = 0.67) inguinal herniorrhaphy with and without resident participation, respectively. Postoperative complications included urinary retention (11.1 vs 2.0%, p = 0.11), conversion to open repair (0 vs 2%, p = 0.48), and delayed reoperation (0 vs 4%, p = 0.22) with and without resident participation, respectively. Patients' symptoms/signs at follow-up were similar among groups. Robotic-assisted TAPP inguinal herniorrhaphy with resident participation as console surgeons did not affect the hospital operative experience or patient outcomes. This procedure can be implemented as part of the resident robotic curriculum with rates of morbidity equivalent to those of published studies.Level of evidence 2b.

"All-in-one mesh" hernioplasty: A new procedure for primary inguinal hernia open repair

BACKGROUND

We propose a new open mesh hernia repair procedure for the treatment of inguinal hernias in adults aiming to improve patients' comfort and to reduce the incidence of chronic neuralgia.

METHODS

From September 2012 to August 2015, 250 consecutive patients were treated with "all in-one" mesh hernioplasty procedure in our Institution. According to the devised technique, a new smaller prosthesis was placed on the floor of the inguinal canal in order to strengthen all areas of weakness from which hernias may originate. The mesh was enveloped by a fibro-cremasteric sheath avoiding contact with neural structures. Follow-up was carried out at 3, 6, 12, 18 and 24 months for evaluation of postoperative pain using Visual Analogue Scale score, need of medication, patients' comfort and short or long-term complications.

RESULTS

All patients were discharged within 24 h from surgery. Slight pain was reported by the majority of patients and 47.6% of them did not require pain medication at home. After the 1st postoperative week 96.8% reported no pain and no other symptoms. No relevant limitation of normal activities was reported. There has been no postoperative neuralgia. One recurrence was observed.

CONCLUSIONS

This new hernioplasty technique respects the anatomy of the inguinal canal, uses a smaller mesh, and seems to avoid neuralgia with maximum comfort for the patients.

Bilateral endoscopic totally extraperitoneal (TEP) inguinal hernia repair does not impair male fertility

PURPOSE

Endoscopic totally extraperitoneal (TEP) hernia repair with polypropylene mesh has become a well-established technique. However, since the mesh is placed in close contact with the spermatic cord, mesh-induced inflammation may affect its structures, possibly resulting in impaired fertility. The aim of this observational prospective cohort study was to assess fertility after bilateral endoscopic TEP inguinal hernia repair in male patients.

METHODS

Fifty-seven male patients (22-60 years old) with primary, reducible, bilateral inguinal hernias underwent elective bilateral endoscopic TEP hernia repair with use of polypropylene mesh. The primary outcome was testicular perfusion; secondary outcomes were testicular volume, endocrinological status, and semen quality. All patients were assessed preoperatively and 6 months postoperatively.

RESULTS

Follow-up was completed in 44 patients. No statistically significant differences in measurements of testicular blood flow parameters or testicular volume were found. Postoperative LH levels were significantly higher [preoperative median 4.3 IU/L (IQR 3.4-5.3) versus postoperative median 5.0 IU/L (IQR 3.6-6.5), p = 0.03]. Levels of inhibin B were significantly lower postoperatively [preoperative median 139.0 ng/L (IQR 106.5-183.0) versus postoperative median 27.0 ng/L (IQR 88.3-170.9), p = 0.01]. No significant changes in FSH or testosterone levels were observed. There were no differences in semen quality.

CONCLUSIONS

Our data suggest that bilateral endoscopic TEP hernia repair with polypropylene mesh does not impair fertility, as no differences in testicular blood flow, testicular volume, or semen quality were observed. Postoperative levels of LH and inhibin B differed significantly from preoperative measurements, yet no clinical relevance could be ascribed to these findings.

Pain and quality of life after inguinal hernia surgery: a multicenter randomized controlled trial comparing lightweight vs heavyweight mesh (Supermesh Study)

Mesh repair has significantly reduced recurrence rate after groin hernia surgery. Recently, attention has shifted to issues such as chronic pain and discomfort, leading to development of lightweight and partially re-absorbable meshes. The aim of the study was to evaluate the effect of lightweight mesh vs heavyweight mesh on post-operative pain, discomfort and quality of life in short and medium term after inguinal hernia surgery. Eight hundred and eight patients with primary inguinal hernia were allocated to anterior repair (Lichtenstein technique) using a lightweight mesh (Ultrapro^®) or a heavyweight mesh (Prolene^®). Primary outcomes were incidence of chronic pain and discomfort at 6-month follow-up. Secondary endpoints were quality of life (QoL), pain and complication at 1 week, 1 and 6 months. At 6 months, 25% of patients reported pain of some intensity; severe pain was reported by 1% of patients in both groups. A statistically significant difference in favour of lightweight mesh was found at multivariable analysis for pain (1 week and 6 months after surgery: p = 0.02 and p = 0.04, respectively) and QoL at 1 month and 6 months (p = 0.05 and p = 0.02, respectively). There was no difference in complication rate and no hernia recurrences were detected. The use of lightweight mesh in anterior Lichtenstein inguinal hernia repair significantly reduced the incidence of pain and favourably affected the perceived quality of life at 6 months after surgery compared to heavyweight mesh.

Risk factors of chronic pain after inguinal hernia repair: a systematic review

Introduction

Chronic postoperative inguinal pain (CPIP) is the most common complication after inguinal hernia operation. Eighteen percent (range, 0.7%-75%) of patients suffered from CPIP after open inguinal hernia repair and 6% (range, 1%-16%) reported CPIP after laparoendoscopic groin hernia repair. The incidence of clinically significant CPIP with impact on daily activities ranged between 10% and 12%. Debilitating CPIP with severe impact on normal daily activities or work was reported in 0.5%-6% of the cases.

Materials and methods

PubMed, Medline, Embase, and the Cochrane Database were searched for studies on risk factors for chronic pain after open and endoscopic hernia repair. A systematic review of the literature was conducted using the grading of recommendations, assessment, development, and evaluations (GRADE) methodology.

Results

Risk factors for CPIP with strong evidence include female gender, young age, high intensity of preoperative pain, high early postoperative pain intensity, history of chronic pain other than CPIP, operation for a recurrent hernia, and open repair technique. Risk factors for CPIP with moderate evidence include postoperative complications, neurolysis, and preservation of the ilioinguinal nerve in Lichtenstein repair. Risk factors for CPIP with low evidence include genetic predisposition (DQB1*03:02 HLA haplotype), lower preoperative optimism, high pain intensity to tonic heat stimulation, inadequate suture/staple/clip mesh fixation, ignorance of the inguinal nerves, less experienced surgeon, sensory dysfunction in the groin, and worker's compensation.

Conclusion

Detailed knowledge of the risk factors, meticulous operative technique with profound knowledge of the anatomy, proper nerve identification and handling, optimization of prosthetic materials, and careful fixation are of utmost importance for the prevention of CPIP.

Long-term Results of a Randomized Double-blinded Prospective Trial of a Lightweight (Ultrapro) Versus a Heavyweight Mesh (Prolene) in Laparoscopic Total Extraperitoneal Inguinal Hernia Repair (TULP-trial)

OBJECTIVE

The aim of the randomized clinical trial was to compare the 2 years of clinical outcomes of a lightweight (Ultrapro) vs a heavyweight (Prolene) mesh for laparoscopic total extraperitoneal (TEP) inguinal hernia repair.

BACKGROUND

Lightweight meshes reduce postoperative pain and stiffness in open anterior inguinal hernia repair. The discussion about a similar benefit for laparoscopic repair is ongoing, but concerns exist about higher recurrence rates.

METHODS

Between March 2010 and October 2012, male patients who presented with a primary, reducible unilateral inguinal hernia who underwent day-case TEP repair were eligible. Outcome parameters included chronic pain, recurrence, foreign body feeling, and quality of life scores.

RESULTS

During the study period, 950 patients were included. One year postoperatively the presence of relevant pain (Numeric Rating Score 4-10) was significantly higher in the lightweight mesh group (2.9%) compared with the heavyweight mesh group (0.7%) (P = 0.01), and after 2 years this difference remained significant (P = 0.03). There were 4 (0.8%) recurrent hernias in the heavyweight mesh group and 13 (2.7%) in the lightweight group (P = 0.03). No differences in foreign body feeling or quality of life scores were detected.

CONCLUSIONS

In TEP hernia surgery, there was no benefit of lightweight over heavyweight meshes observed 2 years postoperatively.

Characterization of persistent pain after hysterectomy based on gynaecological and sensory examination

BACKGROUND AND AIMS

Previous studies have shown that pelvic pain is common after hysterectomy. It is stated that only a minor part of that pain can be defined as persistent postsurgical pain. Our primary aim was to find out if the pelvic pain after hysterectomy may be classified as postsurgical. Secondary aims were to characterize the nature of the pain and its consequences on the health related quality of life.

METHODS

We contacted the 56 women, who had reported having persistent pelvic pain six months after hysterectomy in a previously sent questionnaire. Sixteen women participated. Clinical examinations included gynaecological examination and clinical sensory testing. Patients also filled in quality of life (SF-36) and pain questionnaires.

RESULTS

Ten out of sixteen patients still had pain at the time of examination. In nine patients, pain was regarded as persistent postsurgical pain and assessed probable neuropathic for five patients. There were declines in all scales of the SF-36 compared with the Finnish female population cohort.

CONCLUSIONS

In this study persistent pelvic pain after vaginal or laparoscopic hysterectomy could be defined as persistent postsurgical pain in most cases and it was neuropathic in five out of nine patients. Pain had consequences on the health related quality of life.

IMPLICATIONS

Because persistent postsurgical pain seems to be the main cause of pelvic pain after hysterectomy, the decision of surgery has to be considered carefully. The management of posthysterectomy pain should be based on the nature of pain and the possibility of neuropathic pain should be taken into account at an early postoperative stage.

Risk factors for reoperation due to chronic groin postherniorrhaphy pain

BACKGROUND

Chronic groin postherniorrhaphy pain (CGPP) is common and sometimes so severe that surgical treatment is necessary. The aim of this study was to identify risk factors for being reoperated due to CGPP.

METHODS

All 195,707 repairs registered in the Swedish Hernia Register between 1999 and 2011 were included in the study. Out of these, 28,947 repairs were excluded since they were registered as procedures on the same patient after a previous repair. Age, gender, hernia anatomy (indirect reference), method of repair (anterior sutured repair reference) and postoperative complications were included in a multivariate Cox analysis with reoperation due to CGPP as endpoint.

RESULTS

Of the patients included in the study cohort, 218 (0.13%) later underwent reoperation due to CGPP, including 31 (14%) women. Median age at the primary repair was 61.5 years. Risk factors for being reoperated were age < median [hazard ratio (HR) 3.03, 95% confidence interval (CI) 2.22-4.12], female gender (HR 2.13, CI 1.41-3.21), direct hernia (HR 1.35, CI 1.003-1.81), other hernia (HR 6.03, CI 3.08-11.79), Lichtenstein repair (HR 2.22, CI 1.16-4.25), plug repair (HR 3.93, CI 1.96-7.89), other repair (HR 2.58, CI 1.08-6.19), bilateral repair (HR 2.58, CI 1.43-4.66) and postoperative complication (HR 4.40, CI 3.25-5.96).

CONCLUSIONS

Risk factors for being reoperated due to CGPP in this cohort included low age, female gender, a direct hernia, a previous Lichtenstein or plug repair, bilateral repair and postoperative complications. Further research on how to avoid CGPP and explore the effectiveness of surgery for CGPP is necessary.

Retroperitoneal anatomy of the iliohypogastric, ilioinguinal, genitofemoral, and lateral femoral cutaneous nerve: consequences for prevention and treatment of chronic inguinodynia

PURPOSE

Chronic inguinodynia is one of the most frequent complications after groin herniorrhaphy. We investigated the retroperitoneal anatomy of the iliohypogastric, ilioinguinal, genitofemoral, and lateral femoral cutaneous nerve to prevent direct nerve injury during hernia repairs and to find the most advantageous approach for posterior triple neurectomy.

METHODS

We dissected the inguinal nerves in 30 human anatomic specimens bilaterally. The distances from each nerve and their entry points in the abdominal wall were measured in relation to the posterior superior iliac spine, anterior superior iliac spine, and the midpoint between the two iliac spines on the iliac crest. We evaluated our findings by creating high-resolution summation images.

RESULTS

The courses of the iliohypogastric and ilioinguinal nerve are most consistent on the anterior surface of the quadratus lumborum muscle. The genitofemoral nerve always runs on the psoas muscle. The entry points of the nerves in the abdominal wall are located as follows: the iliohypogastric nerve is above the iliac crest and lateral from the anterior superior iliac spine, the ilioinguinal nerve is with great variability, either above or below the iliac crest and lateral from the anterior superior iliac spine, the genital branch is around the internal inguinal ring, the femoral branch is either cranial or caudal to the iliopubic tract, and the lateral femoral cutaneous nerve is either medial or lateral to the anterior superior iliac spine.

CONCLUSION

Nerve injury during inguinal hernia repairs can be avoided by taking the topographic anatomy of the inguinal nerves into consideration. The most advantageous plane to look for the iliohypogastric and ilioinguinal nerve during posterior neurectomy is on the anterior surface of the quadratus lumborum muscle. For the surgical treatment of severe chronic inguinodynia, especially after posterior open or endoscopic mesh repair (TAPP/TEP), the retroperitoneoscopic or open retroperitoneal approach for posterior triple neurectomy can be considered.

Pain after totally extraperitoneal (TEP) hernia repair might fade out within a year

BACKGROUND

The incidence of chronic pain after endoscopic hernia repair varies between 1 and 16 %. Studies regarding the course of pain in time after the operation are scarce.

METHODS

473 male patients ≥18 years of age, scheduled for totally extraperitoneal (TEP) hernia repair (Prolene® mesh) between March 2010 and August 2012 were requested to record pain symptoms preoperative, and 1 day, 1 week, 6 weeks, 3 months and 1 year postoperatively and visit the outpatient department 3 months and 1 year postoperatively for a standardized interview and physical examination.

RESULTS

Preoperatively, 25 % (n = 114) of the patients had moderate-to-severe pain (NRS 4-10). Six weeks postoperatively, 3 % (n = 12) of the patients still experienced moderate-to-severe pain. Three months after TEP, only 3 patients (0.6 %) had moderate-to-severe pain, while 83 patients (18 %) experienced mild pain. One year after TEP, 39 patients experienced mild pain (8 %) and 3 patients moderate pain (0.7 %), no patients experienced severe pain after 1 year. Patients with moderate-to-severe pain preoperatively had a higher risk of pain persisting until 3 months and 1 year postoperatively (p = 0.03). In most patients who had pain 3 months postoperatively and were pain-free 1 year after TEP, pain 'faded out' at 4-6 months postoperatively. Two patients had a not-painful recurrent hernia, diagnosed 2 and 5 months after TEP repair.

CONCLUSION

Moderate-to-severe pain after TEP hernia repair is self-limiting, with less than 1 % of the patients reporting moderate pain 1 year postoperatively.

Intercostobrachial nerve handling and pain after axillary lymph node dissection for breast cancer

BACKGROUND

Moderate to severe pain in the first week after axillary lymph node dissection (ALND) for breast cancer is experienced by approximately 50% of the patients. Damage to the intercostobrachial nerve (ICBN) has been proposed as a risk factor for the development of persistent pain following breast cancer surgery but with limited information on acute post-operative pain. The aim of the present study was to examine the influence of ICBN handling on pain during the first week after ALND.

METHODS

The study was part of a larger prospective cohort study on persistent pain after breast cancer treatment. Pain and sensory disturbances were assessed pre-operatively, within the first 72 h post-operatively and a week after surgery. Intraoperative handling of the nerve was recorded by the surgeon as preserved, partially preserved or sectioned.

RESULTS

One hundred forty-one patients were treated with ALND level I + II, and the ICBN could be identified in 125 (89%) patients. Of the 17 not identified, eight were stated as without any sign of the nerve and were included in analysis as sectioned. Thus, the analysis included 133 patients in which 45 (34%) of these the ICBN was preserved, 39 (29%) partially preserved and 49 (37%) sectioned. At 1 week after surgery, 104 patients (78%) reported pain, whereas 35 (26%) reported moderate to severe pain. There was no difference between the ICBN groups in pain scores or sensory disturbances measured pre-operatively compared to 1 week post-operatively.

CONCLUSION

The type of ICBN handling during ALND may not influence acute post-operative pain in the first week after surgery.

Description of robotically assisted single-site transabdominal preperitoneal (RASS-TAPP) inguinal hernia repair and presentation of clinical outcomes

BACKGROUND

The aim of our study is to report our initial clinical experience with robotically assisted single-site transabdominal preperitoneal (RASS-TAPP) hernia repair, to verify the safety and efficacy of the procedure and to describe the surgical procedure.

METHODS

We retrospectively reviewed all patients undergoing RASS-TAPP at our institution from March 2013 through December 2013. Data regarding patient demographics, type and location of hernia, operative time and clinical outcomes were collected and analyzed.

RESULTS

Fourty five hernias were repaired in 34 patients (30M, 4F) by a single surgeon. The mean age was 49.3 years and mean BMI was 26.5. 31 lateral defects, 13 medial defects and 1 femoral defect were repaired. Three patients presented with recurrent hernias and nine had bilateral defects. The mean operative time for all cases was 80.5 min and for all unilateral hernias 69 min. Considering just the unilateral hernias without any additional procedures, operative time was 63 min. The mean follow-up time was 5.5 months. There has been one superficial surgical site infection, but no observed clinical recurrence or neuralgia to date.

CONCLUSION

Robotically assisted single-site transabdominal preperitoneal hernia repair is safe and effective. The absence of clinical evidence of recurrence or neuralgia is encouraging and should promote further study.

Descending pain modulation and chronification of pain

PURPOSE OF REVIEW

Chronic pain is an important public health problem that negatively impacts quality of life of affected individuals and exacts an enormous socio-economic cost. Currently available therapeutics provide inadequate management of pain in many patients. Acute pain states generally resolve in most patients. However, for reasons that are poorly understood, in some individuals, acute pain can transform to a chronic state. Our understanding of the risk factors that underlie the development of chronic pain is limited. Recent studies have suggested an important contribution of dysfunction in descending pain modulatory circuits to pain 'chronification'. Human studies provide insights into possible endogenous and exogenous factors that may promote the conversion of pain into a chronic condition.

RECENT FINDINGS

Descending pain modulatory systems have been studied and characterized in animal models. Human brain imaging techniques, deep brain stimulation and the mechanisms of action of drugs that are effective in the treatment of pain confirm the clinical relevance of top-down pain modulatory circuits. Growing evidence supports the concept that chronic pain is associated with a dysregulation in descending pain modulation. Disruption of the balance of descending modulatory circuits to favour facilitation may promote and maintain chronic pain. Recent findings suggest that diminished descending inhibition is likely to be an important element in determining whether pain may become chronic. This view is consistent with the clinical success of drugs that enhance spinal noradrenergic activity, such as serotonin/norepinephrine reuptake inhibitors (SNRIs), in the treatment of chronic pain states. Consistent with this concept, a robust descending inhibitory system may be normally engaged to protect against the development of chronic pain. Imaging studies show that higher cortical and subcortical centres that govern emotional, motivational and cognitive processes communicate directly with descending pain modulatory circuits providing a mechanistic basis to explain how exogenous factors can influence the expression of chronic pain in a susceptible individual.

SUMMARY

Preclinical studies coupled with clinical pharmacologic and neuroimaging investigations have advanced our understanding of brain circuits that modulate pain. Descending pain facilitatory and inhibitory circuits arising ultimately in the brainstem provide mechanisms that can be engaged to promote or protect against pain 'chronification'. These systems interact with higher centres, thus providing a means through which exogenous factors can influence the risk of pain chronification. A greater understanding of the role of descending pain modulation can lead to novel therapeutic directions aimed at normalizing aberrant processes that can lead to chronic pain.

Persistent postsurgical pain: evidence from breast cancer surgery, groin hernia repair, and lung cancer surgery

The prevalences of severe persistent postsurgical pain (PPP) following breast cancer surgery (BCS), groin hernia repair (GHR), and lung cancer surgery (LCS) are 13, 2, and 4-12 %, respectively. Estimates indicate that 80,000 patients each year in the U.S.A. are affected by severe pain and debilitating impairment in the aftermath of BCS, GHR, and LCS. Data across the three surgical procedures indicate a 35-65 % decrease in prevalence of PPP at 4-6 years follow-up. However, this is outweighed by late-onset PPP, which appears following a pain-free interval. The consequences of PPP include severe impairments of physical, psychological, and socioeconomic aspects of life. The pathophysiology underlying PPP consists of a continuing inflammatory response, a neuropathic component, and/or a late reinstatement of postsurgical inflammatory pain. While the sensory profiles of PPP-patients and pain-free controls are comparable with hypofunction on the surgical side, this seems to be accentuated in PPP-patients. In BCS-patients and GHR-patients, the sensory profiles indicate inflammatory and neuropathic components with contribution of central sensitization. A number of surgical factors including increased duration of surgery, repeat surgery, more invasive surgical techniques, and intraoperative nerve lesion have been associated with PPP. One of the most consistent predictive factors for PPP is high intensity acute postsurgical pain, but also psychological factors including anxiety, catastrophizing trait, depression, and psychological vulnerability have been identified as significant predictors of PPP. The quest to identify improved surgical and anesthesiological techniques to prevent severe pain and functional impairment in patients after surgery continues.