3 Evidence

Clinical evidence

3.1 All clinical evidence was reported when the technology was called TURis (transurethral resection in saline). Now it is called the PLASMA system.

Relevant evidence in original guidance comes from 10 studies and 1 meta-analysis

3.2 For the medical technologies guidance on TURis that this guidance replaces, the external assessment centre (EAC) considered 10 unique randomised studies (1,870 people) and 1 meta-analysis from the company. The studies relevant to the decision problem in the scope were:

  • 8 papers (Akman et al. 2013; Chen et al. 2009; Chen et al. 2010; Fagerstrom et al. 2009; Fagerstrom et al. 2011; Geavlete et al. 2011; Ho et al. 2007; Michielson et al. 2007)

  • 2 foreign language papers with English abstracts (Rose et al. 2007; Abascal Junquera et al. 2006)

  • 1 multicentre study published in 4 abstracts (Goh et al. 2009; Gular et al. 2009; Gular et al. 2010a; Gular et al. 2010b).

    For full details of the clinical evidence, see section 3 of the original assessment report in supporting documentation.

PLASMA has equivalent clinical effectiveness to mTURP

3.3 All studies reported equivalent clinical effectiveness for resection of the prostate for PLASMA compared with monopolar transurethral resection of the prostate (mTURP).

PLASMA eliminates transurethral resection (TUR) syndrome

3.4 No cases of TUR syndrome were seen with PLASMA (Akman et al. 2013; Ho et al. 2007; Fagerstrom et al. 2009 and 2011; Gleavlete et al. 2011; Chen et al. 2009 and 2010).

PLASMA reduces bleeding

3.5 In the 3 studies where it was reported, fewer people needed a blood transfusion in the PLASMA group compared with mTURP (Chen et al. 2009 and 2010; Geavlete et al. 2011).

PLASMA reduces length of hospital stay

3.6 The PLASMA system reduced the length of hospital stay in 2 studies (Chen et al. 2009; Gleavlete et al. 2011).

New relevant evidence comes from 2 studies in 3 publications, including 1 randomised controlled trial

3.7 For the guidance update, the EAC considered 2 new studies reported as 3 papers (156 people) relevant to the decision problem in the scope:

PLASMA reduces the length of hospital stay

3.8 Hospitalisation time (mean days) was significantly higher in the mTURP group (3.4) compared with the PLASMA group (2.5; p=0.045; Komura et al. 2014 and 2015).

PLASMA has been associated with an increased rate of urethral stricture

3.9 Komura et al. (2015) reported a rate of urethral stricture at 36 months. This was 4 out of 61 (6.6%) in the mTURP group and 12 out of 63 (19%) in the PLASMA group (p<0.022). Komura et al. (2015) also reported on the anatomical location of the strictures and the treatment. The incidence of urethral stricture was not reported in Karadeniz et al. (2016).

Cost evidence

The company provided an executable Excel model of a simple decision tree

3.10 For the guidance update, the EAC updated the parameters of the model from the company. For full details of the cost evidence, see the assessment report update in supporting documentation. The company model assumed no change in length of stay for mTURP but a reduced length of stay with PLASMA.

3.11 The EAC contacted 3 professional experts and the company. They were asked to comment on whether the assumptions and parameters used in the original model were still valid for the update or whether there were any changes. There was no suggestion that assumptions on the cost of generators or single-use electrodes were invalid. One professional expert advised that there was recent evidence that bipolar TURP was associated with higher rates of strictures and contractures compared with mTURP. See sections 3.12 to 3.15 for additional comments from the professional experts.

There is uncertainty about whether bipolar electrosurgery is standard care

3.12 Two professional experts indicated that most TURP procedures now use bipolar electrosurgery devices as standard care. The company advised that 100 NHS centres were using PLASMA in 2019, compared with 61 in 2015 (England, Scotland, and Wales). A third professional expert indicated that, in his opinion, bipolar should be seen as the 'gold standard' for electrosurgical TURP treatment. However, the experts also reported that other companies that make bipolar systems have been slow to develop reliable devices. This means that hospitals that rely on these companies have been slow to change from monopolar to bipolar TURP as their standard technique.

Blood transfusion rates and volumes may now be lower

3.13 Three professional experts stated that blood transfusion rates and volumes of blood given may be lower now. Two professional experts indicated that the haemoglobin threshold for starting blood transfusion had decreased from 80 g/litre to 70 g/litre. Or, it was restricted to patients who are symptomatic because of blood loss. Two professional experts advised that transfusion rates are very low, probably lower than the 5.8% used for monopolar TURP in the original model. Another indicated that 2.7 units of red blood cells used in the model seemed high and suggested that 1 to 2 units was more likely.

PLASMA is associated with better haemostasis

3.14 There is an overall indication that PLASMA is associated with better haemostasis than mTURP (based on lower blood transfusion rates and increased use of coagulating electrodes). Therefore, a lower rate of admissions for haemorrhage would be expected for PLASMA.

Using the PLASMA button electrode for vaporisation is out of scope for this guidance but using it for haemostasis is in scope

3.15 When used with the generator in cut mode, the PLASMA button electrodes cause transurethral vaporisation of the prostate (TUVP). This uses a plasma effect as an alternative to resection using a loop electrode. All 3 professional experts and the company considered this to be a separate procedure to PLASMA TURP. The evidence base is distinct and the clinical outcome values in the TURP model should not be transferred into a model of PLASMA TUVP compared with mTURP. Previously the model assumed that 22% of PLASMA resections also included using a roller electrode for haemostasis. All 3 professional experts advised that using the button electrode for haemostasis (generator in coagulate mode) after loop resection is now relatively common. Two professional experts stated that they use the PLASMA button electrode for haemostasis after resection with a loop electrode. They suggested that this produces better haemostasis, therefore a lower risk of transfusion and higher chance of treatment as a day case. One professional expert stated that they suspected many of these cases unavoidably caused some vaporisation of prostate tissue, although the primary intention is haemostasis.

The original base case for PLASMA is cost saving assuming a 0.19-day reduction in length of stay of PLASMA compared with mTURP at sites with an existing Olympus system and cost incurring at other sites

3.16 In the original base case, for a 0.19-day reduction in length of stay for PLASMA and 2-day length of stay for mTURP with an existing Olympus system, mTURP costs £1,196.60 and PLASMA costs £1,126.04. This is a cost saving of £70.56. For non-Olympus sites, mTURP costs £1,125.69 and PLASMA costs £1,145.49. This is a cost increase of £19.80. This original base case assumed a second electrode was used for 22% of procedures.

The updated base case for PLASMA is cost saving with a 2-day length of stay compared with a 3.3-day length of stay for mTURP

3.17 For a 3.3-day length of stay with an existing Olympus system, mTURP costs £1,510.32. For a 2-day length of stay with an existing Olympus system, PLASMA costs £1,051.42. This is a cost saving of £458.91. For non-Olympus sites and a 3.3-day length of stay, mTURP costs £1,415.86. For non-Olympus sites and a 2-day length of stay, PLASMA costs £1,073.02. This is a cost saving of £342.84. In the updated base case, 65% of procedures were assumed to need a second electrode for haemostasis.

PLASMA is cost saving for a 1-day length of stay (day case)

3.18 For a 1-day length of stay (day case) for PLASMA and a 3.3-day length of stay for mTURP with an existing Olympus system, mTURP costs £1,510.32 and PLASMA costs £662.42. This is a cost saving of £847.91. For a non-Olympus site, mTURP costs £1,415.86 under these circumstances and PLASMA costs £684.02. This is a cost saving of £731.84. In this scenario, 65% of procedures were assumed to need a second electrode for haemostasis.

PLASMA is cost saving for a 2-day length of stay when not using a second electrode for haemostasis

3.19 The EAC modelled an additional scenario with no second electrode. For a 3.3-day length of stay for mTURP and an existing Olympus site when no second electrode used for haemostasis, the cost is £1,510.32, and PLASMA costs £932.71 for a 2-day length of stay. This gives a cost saving of £577.61. For a 3.3-day length of stay for mTURP and a non-Olympus site with no second electrode, the mTURP cost is £1,415.86 and the PLASMA cost is £954.31 for a 2-day length of stay. This gives a cost saving of £461.55.

PLASMA is cost saving for a 2-day length of stay when a second electrode is used for haemostasis in 65% of procedures and all-cause readmissions are reduced

3.20 The EAC modelled an additional scenario with 65% of procedures needing a second electrode and reduced all-cause readmissions. For mTURP and an existing Olympus site when a second electrode is used for haemostasis in 65% of procedures, the cost is £1,621.25, and PLASMA costs £1,086.94. This is a cost saving of £534.34. For mTURP and a non-Olympus site when a second electrode is used in 65% of procedures, the mTURP cost is £1,526.79 and PLASMA costs £1,108.38. This gives a cost saving of £418.41.

  • National Institute for Health and Care Excellence (NICE)