This study protocol was approved by the ethics committee of the Hunan Provincial People's Hospital (NO. 2019705). Informed consent of each participant was obtained for study inclusion. All methods were carried out in accordance with relevant guidelines and regulations.
Registration: Chinese Clinical Trial Registry, 08/03/2021, ChiCTR2100044034. [A new type of balloon catheter-based dilatation intervention for patients with dysphagia after stroke: a randomized controlled trial]
Design
This is a randomized controlled trial with concealed allocation, intention-to-treat analysis and blinded assessment. The study was performed in the Department of Rehabilitation at Hunan Provincial People's Hospital, Changsha, Hunan, China. Patients in hospital with cricopharyngeus achalasia after stroke who need the dilatation therapy were invited to participate the study. Eligible and willing participants received routine swallowing training and nursing care, and were randomly divided into the experimental group (treated with the new type balloon catheter) and control group (treated with No.14 ordinary urinary catheter) in a 1:1 ratio. All participants had the following data collected: age, gender, cause of dysphagia, comorbidities and the course of disease.
Concealed allocation of the randomization was performed using a computer-generated random sequence and opaque envelopes by a researcher who did not involve in this study. This research informed only the physiotherapist who administered the intervention for each patient. Another rehabilitation physician who was blinded to the information measured the outcomes.
Dilatation were commenced after baseline measurements and were continued one time per day, 5 days per week. EAT-10 score, FOIS score, ability of oral intake and complications were assessed every day during intervention by a rehabilitation physician blinded to the study. This physician decided whether the dilatation therapy should be terminated or not. If the swallowing function recovered basically before completing the intervention protocol period, outcomes were measured after the last dilatation intervention to homogenize the analyses.
Participants
Patients with cricopharyngeus achalasia after stroke who need dilatation therapy in hospital were recruited, screened for eligible and willing to participated in this study from July 2019 to July 2021. The inclusion criteria included: 1) having a diagnosis of cricopharyngeus achalasia confirmed by the video fluoroscopy swallowing study or clinical swallowing evaluation; 2) Radiologists confirmed stroke by head Magnetic Resonance Imaging; 3) being aged 20 -80 yeas. The excluded criteria included: 1) organic obstruction of nasal or pharyngeal; 2) sever heart, lung and kidney diseases; 3) mental illness; 4) severe cognitive disorder and aphasia.
Intervention
Routine swallowing rehabilitation trainings were performed on all of the participants including the basic swallowing training (oral and facial function training and Shaker training, one time per day with 30 mins/time), oral intake training and the Vitalstim electrical stimulation (one time per day with 30min/time). Nutritional and mental care were provided to all participants.
Experimental Group
Patients in this group undertook dilatation therapy using this new type balloon catheter with following steps.
New type balloon catheter
This new balloon catheter consists of a Y-shaped connector with inlet and outlet valve, a catheter body and a balloon (Fig 1C). The catheter body is divided into two cavities (inlet cavity and outlet cavity) which are connected to the inlet and outlet valve respectively. Both of the cavities are connected to the balloon. Water can be injected from the inlet valve, flows through the inlet cavity to the balloon, passes through the balloon to the outlet cavity, then flows out from the outlet valve (Fig 1A). There are several advantages of this new balloon catheter:
1. Contrast to the No.14 ordinary urinary balloon catheter (Fig 1B) which only have single cavity, this new balloon catheter with double-cavities separates the inlet and outlet water to ensure that the water can continuously and evenly flow in and out of the catheter.
2. The shape of the new balloon is ellipsoid instead of sphericity after being completely filled (Fig 1D), which is conducive to more adequate expansion of the cricopharyngeal muscle.
3. The catheter is marked with a scale so that the operator could clearly read the depth of catheter insertion.
Dilatation steps:
Step 1: Patients were asked to fast 2 hours before dilatation. The catheter was gently inserted into the patient's nasal cavity (or oral cavity when patient's deglutition reflex disappeared) after confirming its integrity. At the same time, patients were instructed to swallow. When the catheter was completely inserted into the esophagus (about 30 cm in length from nasal cavity), patients were asked to make sounds. If they sounded normal without cough, can proceeded to the next step.
Step 2: After the catheter was fully inserted into the esophagus, opened the inlet and outlet of the Y-connector, injected ice water into the inlet cavity continuously using a syringe. Kept the ice water flowing in and flowing out for 3-5 minutes.
Stpe3: Closed the outlet valve and injected 5-7ml of ice water to fill the balloon, then closed the inlet valve.
Step 4: After that, operator could pull out the catheter gently. When the balloon passed through the cricopharyngeal muscle (the position where the catheter was hard to pull out), the balloon size can be adjusted by adjusting the water volume of the balloon to ensure that the operator can only feel slight resistance. At the same time, operator pulled the balloon slowly and repeatedly while instructing the patient to swallow until the balloon leaved the esophagus.
Step 5: After the balloon leaved the esophagus, opened the outlet valve to drained the water, then pulled out the catheter completely.
Step 6: Repeated the above steps 5-6 times, and the whole treatment lasted about 30 minutes.
Note: The balloon volume increased by 1-2ml daily with total amount <20ml.
Control group
Patients in this group undertook dilatation therapy using No.14 ordinary urinary catheter with following steps.
Step 1: The same as the exp group
Step 2: After the catheter was completely inserted into the esophagus, 1-2ml of ice water was injected into the balloon and then closed the inlet valve.
Step 3: Operator pulled out the catheter gently until the balloon leaved the esophagus, while instructed the patient to swallow. The specific process was the same as the experimental group.
Step 4: After the balloon leaved the esophagus, withdrawn the ice water from the balloon with a syringe, and then pulled the catheter completely out of the patient. Subsequently, drained the remaining water and repeated the above steps for 5-6 times. The entire process lasted about 30 minutes.
Note: The same with Exp group.
Outcome measures
All participants were assessed before and every day during intervention period by the rehabilitation physician blinded to this study using the following measurements. The primary outcome was the durtaion of dilatation which was quantified in days until the recovery of the swallowing function assessed by the physician using the criteria as FOIS score of 6 or more. Swallowing function was performed using the FOIS score12 and EAT-10 score system13. EAT-10 score is composed of 10-item question including various symptoms of dysphagia, clinical characteristics, psychological feelings and social influence. Each question is divided into 5 levels: none (0), mild (1), moderate (2) severe (3) and extreme (4). A final total EAT-10 score of 3 or more is considered abnormal. FOIS score categorizes oral intake into 7 grades from I to VII, corresponding to 1 to 7 points respectively. When FOIS score up to 3 or more, the clinical outcome is considered to be significantly improved. Oral intake training was administrated every day during intervention period by the physician using one-bite size of water, liquid food, mushy food or solid food. According to the water swallow test, recovery of oral intake of water was defined as swallow at once without coughing. During the intervention period, complications, like laryngeal edema and mucosal hemorrhage were evaluated for all patients by the rehabilitation physician and the senior nurse who were blinded to the study. Pain status were assessed using a five-point oral grading scale (VRS-5) 14(0 points for painlessness, 1-5 points for mild pain, moderate pain, severe pain, extreme pain, and intolerable pain, respectively) by the nurse.
Data analysis
Sample size was calculated based on the primary outcome of duration of intervention. Mean duration of 8 days for Exp group and 16 days for Con group with a standard deviation of 10 and 2 respectively were anticipated, and a significance level of 5% and study power of 86% were used. Finally, it was calculated that a sample of 50 participants (25 per group) was required. Totally, sample size of 52 participants were used to allow the possible loss.
All data analyses were performed by a researcher who was not involved in this study assessments and interventions. Baseline characteristics of the participants were summarized with descriptive statistics. Statistical analysis was performed following the intent-to-treat principle. The Kruskal-Wallis ANOVA was use for the continuous variables, like: EAT-10 score, the recovery time for oral intake of water, liquid food, mushy food. Due to non-normal distribution of the data, the between-group difference in the duration of dilatation and the recovery time for oral intake of solid food were investigated using Mann-Whitney U test. Chi-square tests were used for the categorical variables (complications). Kaplan-Meier survival analysis was used to test the duration time. A significance level of 5% (p <0.05) was adopted for all statistical analyses. All of the statistical analyses were performed using SPSS (IBM).