Evidence review | The PolySoft hernia patch used with the ONSTEP technique to treat inguinal hernias | Advice

Clinical and technical evidence

Two published studies of the PolySoft hernia patch used with the ONSTEP inguinal hernia repair technique were identified. Both studies are case series that reported initial experience in surgery. Lourenço and da Costa (2013) reported the initial clinical experience of 693 patients having surgery performed by 2 different surgeons in 2 Portuguese hospitals (see table 1).

Table 1 Summary of the Lourenço and da Costa (2013) study

Study component		Description
Objectives/hypotheses		To report on initial experience with a novel hernioplasty procedure: the PolySoft repair patch with the ONSTEP repair technique.
Study design		Reporting surgery results. The follow‑up period was a visit between 1 and 2 months after surgery and another 1 year after surgery.
Setting		Hernia repair surgery at 2 Portuguese hospitals.
Inclusion/exclusion criteria		Adults (>18 years) having inguinal hernia repair surgery.
Primary outcomes		Duration of surgery, absence of chronic pain, time taken to return to normal activities, and complication and recurrence rates.
Statistical methods		Simple averages, standard deviations and percentage rates were used to quantify the outcomes and complications.
Participants		693 adults having inguinal hernia repair.
Results	ONSTEP hernia repair using the PolySoft patch		Analysis
Participants	n=693		577 and 116 patients were treated at each hospital.
Patient characteristics	Men/women, n=579/114 (82%/18%) Mean age (years) [±SD]=60.6 [±7.5] Age range (years)=18–86 Type of hernia: direct=254 (37%), indirect=429 (62%), femoral=10 (1%), previous hernioplasty=76 (11%)		No comments were made in the paper discussing the population. 18% of women is a higher proportion than expected for this patient group.
Outcomes	Duration of surgery: mean (minutes) [SD]=17 [±6], range (minutes)=12–32 Time to discharge (range in hours)=2–23 Time to return to daily activities: mean (days) [SD]=6.1 [±3.0], range (days)=3–10		A study of 106 patients having open TEP hernia repair found the mean duration of surgery was 32.6 ±10.5 minutes. (Yang et al. 2010)
Complications	Early complications (within 1 week): seroma=3 (0.4%), haematoma=2 (0.3%), wound infection=3 (0.4%)		Overall complication rate was 0.7%. Complications in open TEP by Yang et al. (2010) was 11.3%.
	Late complications (6 months): residual pain=4 (0.6%)		Residual pain was resolved by the removing the memory ring in 3 patients and pain disappeared spontaneously in the other.
	Recurrence (all within 2 months): overall, n=4 (0.6%), women, n=3/114 (2.6%), men, n=1/579 (0.2%)		Recurrence after open TEP hernia repair was 1.9% (Yang et al. 2010), laparoscopic TEP repair 0% to 9% (McCormack et al. 2005, Kuhry et al. 2007, Napier et al. 2008)
Conclusions	The ONSTEP procedure using the PolySoft hernia patch was found to be simple and reliable and was associated with very low complication and recurrence rates. The extended lateral recoil ring in the mesh was responsible for the few complications (residual pain) observed. The report suggests that the use of a different prosthesis may help improve outcomes, but does not offer a specific alternative. Long‑term follow‑up is awaited as well as randomised trials to compare with other hernia repair techniques.
Abbreviations: n, number of patients; SD, standard deviation; TEP, total extraperitoneal repair.

Andresen et al. (2014) reported on the initial clinical experience of introducing the ONSTEP technique for inguinal hernia repair in a general surgical department. The study involved 80 patients who were treated by 4 surgeons at a Danish hospital (see table 2).

Table 2 Summary of the Andresen et al. (2014) study

Study component		Description
Objectives/hypotheses		To investigate postoperative pain and complications after ONSTEP repair of inguinal hernia.
Study design		A report of the first 80 surgery results. Follow‑up involved all patients being asked by letter in January 2013 to complete an Inguinal Pain Questionnaire, a Carolinas Comfort Scale and an Activity Assessment Scale. The median follow‑up time was 4 months with a range of 1 to 13 months.
Setting		Hernia repair surgery by 4 surgeons at a Danish hospital.
Inclusion/exclusion criteria		Patients having inguinal hernia repair who chose the ONSTEP technique. All patients were free to choose the Lichtenstein repair technique instead.
Primary outcomes		Duration of surgery and complications including post‑operative pain and recurrence.
Statistical methods		Simple averages and percentages were used to report the outcomes.
Participants		80 patients having inguinal hernia repair.
Results	Standard method		Analysis
Participants	n=80
Patient characteristics	Men/women, n=77/3 (96.3%/3.7%) Median age (years)=64 Age range (years)=19‑93 Type of hernia: direct=28 (35%), indirect=49 (61%), femoral=3 (4%)
Outcomes	Duration of surgery: median (minutes)=24, range (minutes)=13–53		Defined as cut to suture time.
	68 (85%) patients responded to the questionnaires.		66 in men and 3 in women (1 of the men had a double hernia, so 69 hernias in 68 patients).
	Activity Assessment Survey results: 53 patients (80.3%) had a score of less than 8.3, which was defined as no substantial impairment of function. No patient had any activity they were unable to perform.		Of the 68 responses: 65 (95.6%) patients completed this survey.
	Carolinas Comfort Scale results: 3 (5.2%) had a mean overall score >1. 4 (6.9%) had a mean mesh comfort score >1. 3 (5.2%) had a mean pain score >1. 3 (5.2%) had a mean movement score >1. No patients reported disabling symptoms in any categories.		58 (85%) patients completed this survey. A mean score >1 in any of the categories was considered symptomatic.
	Inguinal Pain Questionnaire results: 54 (80.6%) patients reported no pain. 10 (14.9%) patients reported pain that was easily ignored. 3 (4.5%) patients reported pain that could not be ignored and interfered with daily activities.		67 (98.5%) patients completed this survey. Three patients reported taking pain medication in the week before answering this survey. 80.9% of the patients reporting no pain also reported no pain 1 month post‑surgery.
Complications	Perioperative complications, n=0 (0%) Contacted the department within 30 days, n=6 (7.5%): 1 superficial infection, 3 haematomas, 1 seroma and 1 case of discomfort related to the memory ring.		All complications were managed conservatively and/or with watchful waiting.
Conclusions	The ONSTEP technique seemed a safe method for inguinal hernia repair in terms of perioperative and postoperative complications. The occurrence rate of postoperative pain was equal to or lower than that after the Lichtenstein procedure. Further studies are needed, ideally blinded randomised clinical trials, before broader implementation.
Abbreviations: n, number of patients; SD, standard deviation.

Two ongoing or in‑development trials on the PolySoft patch for use with the ONSTEP technique were identified in the preparation of this briefing.

Chronic pain after inguinal hernia repair, the ONSTEP technique versus the laparoscopic approach (ONLAP). This trial is not yet recruiting.
ONSTEP versus Lichtenstein, the Onli Trial. This trial is in the recruitment phase.

Costs and resource consequences

In 2012/13, approximately 75,325 surgical interventions were performed in England for inguinal, umbilical or femoral hernia procedures (NHS reference cost 2012/13 code FZ18E, G–K; Department of Health 2013). Usage of the PolySoft hernia patch will depend on how widely the ONSTEP technique is adopted. At present, the number of surgeons trained in the technique is limited.

Use of the PolySoft hernia patch will not need any changes to the way in which current services are organised or delivered. No additional facilities or technologies are needed alongside the PolySoft hernia patch when used with the ONSTEP technique. However, no published evidence on the resource consequences of the PolySoft hernia patch used with the ONSTEP technique was identified in the systematic review of evidence. The manufacturer states that the resource implications of the ONSTEP technique compared with standard open or laparoscopic hernia repair are likely to be realised because of the reduction in treating postoperative complications such as chronic pain and the recurrence of hernias.

Strengths and limitations of the evidence

Both clinical studies were case series documenting initial experience with the device for this technique. They both used single study groups consisting of patients having inguinal hernia repair. The 2 studies described were completed in Portugal and Denmark, and 3 specialist commentators considered that these cohorts of patients would generally reflect those found within the UK.

Neither study identifies how much specific training the surgeons had received with the PolySoft hernia patch and ONSTEP technique, at the time of performing the procedures described. Two of the specialist commentators estimated that the learning curve for this procedure would be 20–30 procedures for a surgeon experienced in the Lichtenstein technique, but the third specialist commentator felt that it would be closer to 5–10. Surgeons who were at an earlier stage in their training would be assigned patients with few or no complications, for example, avoiding those with recurrent hernia or obesity.

A comparison of complication rates was made with other devices and repair techniques by using findings from previous studies conducted at different centres, rather than with a comparator group having an alternative intervention within the same study. A meta‑analysis was not conducted, so there were no statistical comparisons. This is a general weakness of this type of study, but it is common for new surgical techniques because the priority is to assess if the technique is viable.

A more thorough comparison of hernia repair techniques could be made with a meta‑analysis or random allocation of patients into groups for side‑by‑side trial study. This would allow a more accurate determination of the relative complication rates. Both papers acknowledge this in their conclusions by stating a preference for randomised clinical trials.

Lourenço and da Costa (2013) used 2 fixed follow‑up periods of 1–2 months after surgery and 1 year after surgery. This method aimed to collect both short‑term and longer‑term complications.

Andresen et al. (2014) used a fixed date of January 2013 for their follow‑up. Therefore patients were assessed between 1 and 13 months after surgery.

Both follow‑up methods have advantages and disadvantages. Follow‑up on a fixed date gives a greater spread of time after surgery, but may miss longer‑term complications that are yet to appear. There may be a case for follow‑up being conducted at fixed times after surgery for each patient, if those times can be shown to have clinical relevance. For example, if the follow‑up time is too short, pain reported could be caused by normal post‑operative recovery rather than chronic pain. Longer experience of using the PolySoft patch is needed to ensure the follow‑up times are suitable to detect any complications that may be expected. Both studies express a preference for a longer follow‑up period in their conclusions.

Specialist commentator opinions varied in terms of a suitable length of follow‑up. Short‑term complications would be identified within the first month but for long‑term complications a 2‑5‑year follow‑up was suggested, otentially backed by data from surgical registries.