NaviCam for diagnosing gastrointestinal tract conditions

Liao et al. 2016

Study size, design and location

Single-blind (investigator), single-arm diagnostic accuracy study in 350 patients with upper gastrointestinal (GI) tract complaints.

Done in 7 tertiary referral centres in China.

Patients were examined with the NaviCam first, followed by gastroscopy 2 hours later. Primary outcomes: sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) to detect gastric focal lesions (positive result defined as polyp, ulcers, submucosal tumour or other [such as xanthoma, diverticulum]), using gastroscopy as the reference standard.

Intervention and comparator(s)

The NaviCam (gastroscopy as the reference standard), gastroscopy for assessing patient preference.

Key outcomes

The NaviCam detected focal lesions in the upper and lower stomach with comparable accuracy using conventional gastroscopy as the reference standard. The NaviCam detected gastric focal lesions in the whole stomach with 90.4% sensitivity, 94.7% specificity, a PPV of 87.9%, a NPV of 95.9% and 93.4% accuracy. The NaviCam was preferred by almost all patients (95.7%), compared with gastroscopy. The authors concluded that the NaviCam can be used to screen gastric diseases without sedation.

Strengths and limitations

Authors had no reported conflicts of interest. Gastroscopy was done without sedation. Subjects were unblinded and had concurrent procedures, but investigators were blinded to the results from different procedures. People with overt GI bleeding were excluded. Oesophagus and small bowel were not assessed.

Zou et al. 2015

Study size, design and location

Single-blind (investigator blinded to results), single-arm diagnostic accuracy study in 68 patients.

Done in 2 tertiary centres in China.

Patients were examined with the NaviCam first, followed by conventional gastroscopy 4 to 24 hours later. Primary outcome: degree of agreement between the NaviCam and gastroscopy for the diagnosis of gastric lesions.

Intervention and comparator(s)

The NaviCam
Olympus gastroscopy.

Key outcomes

The NaviCam showed a diagnostic accuracy similar to standard gastroscopy: the positive percent agreement was 96.0%, and the negative percent agreement was 77.8%. The overall agreement was 91.2% with a κ value of 0.765 (p<0.001). A total of 68 pathological findings were detected, of which 53 were identified by both methods. The NaviCam and gastroscopy missed 7 and 8 findings respectively.

The NaviCam procedure time was longer than gastroscopy: 29.1±8.5 minutes (range 8 to 53 minutes) compared with 5.0±1.0 minutes (range 3.0 to 7.2 minutes) for gastroscopy (p<0.001).

There were 2 cases of temporary abdominal pain and 1 case of chronic diarrhoea with the NaviCam.

Strengths and limitations

No reported conflicts of interest. Subjects were unblinded and had concurrent procedures, but investigators were blinded.

Liao et al. 2012

Study size, design and location

Feasibility and safety study in 34 healthy volunteers.

Done at a single centre in China.

Subjects were examined with NaviCam and were followed up for 14 days. Endpoints included adverse events, patient tolerability, overall manoeuvrability and visualisation of the gastric mucosa.

Intervention and comparator(s)

The NaviCam.

Key outcomes

The procedure took 43.8±10.0 minutes (range 27 to 60 minutes). Manoeuvrability was graded as good in 29 (85.3%) people and moderate in 5 (14.7%) people. More than 75% gastric mucosa was visualised in 27 (79.4%) people and 50% to 75% in 7 (20.6%) people. Visualisation of the gastric cardia, fundus, body, angulus, antrum and pylorus was subjectively assessed as complete in 82.4%, 85.3%, 100.0%, 100.0%, 100.0% and 100.0% respectively.

Gastric preparation and examination was well tolerated and there were no adverse events.

The authors concluded that the NaviCam used for examination of the stomach is feasible and safe.

Strengths and limitations

Single-arm study in a small number of healthy people, not the indicated population.

Tang et al. 2016

Study size, design and location

Feasibility study in 30 children (aged 7 to 16 years).

Done at a single centre in China.

Intervention and comparator(s)

The NaviCam.

Key outcomes

No adverse events were reported. 4 children failed to swallow the capsule, but it was successfully delivered using a transparent hood-assisted endoscopic device applied to the top of the oesophagus. The authors concluded that the NaviCam is feasible and safe for the diagnosis of suspected gastric disease in children.

Strengths and limitations

Small feasibility single-centre study in children with no comparator. The authors' conflicts of interest are unknown. Poster presentation only.

Qian et al. 2016

Study size, design and location

Feasibility study in 30 healthy volunteers and 30 patients with GI complaints.

Done at a single centre, China.

Attempts to optimise the NaviCam visualisation by changing body position: patients were asked to adopt 5 body positions (left lateral, supine, right lateral, knee-chest, and sitting). In each position, the ability to visualise 6 gastric landmarks (cardia, fundus, body, angulus, antrum, and pylorus) was assessed.

Intervention and comparator(s)

The NaviCam.

Key outcomes

A 5-position combination improved visualisation of gastric landmarks compared to the conventional 3-position combination (93.3%, p<0.001). Supine position was the best for cardia and body visualisation (91.7% and 86.7% respectively, p<0.001). Left lateral position was the best for fundus visualisation (91.7%, p<0.001). Knee-chest position was the best for angulus observation (80.0%, p<0.001). Right lateral and sitting positions were the best for antrum observation (88.3% and 90.0% respectively, p<0.001). Right lateral position was the best for pylorus observation (81.7%, p<0.001).

Strengths and limitations

Single-arm feasibility study. Adoption of all positions may not be possible by patients in clinical practice (for example older or very young people).

Abbreviations: N/PPV, negative/positive predictive value; GI, gastrointestinal.