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Percutaneous dilatational tracheostomy compared with conventional surgical tracheostomy in neurosurgery intensive care unit

Address for Correspondence: Dr. Shiwani Rai, Assistant Professor, Department of ENT-HNS, Manipal Teaching Hospital, Pokhara Nepal. Phone: 00977-9816673508. E-mail: shiwani.rai@manipal.edu.np Background: Tracheostomy is a commonly performed procedure in intensive care units (ICU). Percutaneous dilatation tracheostomy (PDT) has achieved wide acceptance recently since its first introduction by Ciagila in 1985. Aims and Objective: The current study was designed and aimed to compare conventional tracheostomy (CT) with percutaneous dilatation tracheostomy using Grigg’s GWDF technique in terms of operative timing, duration of ICU and hospital stay and complications. Materials and Methods: A prospective, single blinded, randomized study was done in between April 2019 to December 2019. Patients were randomly assigned into CT group and PDT group of 32 patients in each group. Data were recorded in terms of demographics, preoperative diagnosis, GCS, comorbidities, ICU stay, hospital stay, decanulation time, operative time and various complications. Data were compared using student’s t test for continuous variables and Chi-squared test or Fisher’s exact test for categorical variables. Data were analyzed using IBM SPSS statistics version 20. Results: Mean operative time in CT group was 35.00±9.56 min and in PDT group was 18.17±8.78 min and the difference was statistically significant (p=0.00). Similarly, there was statistically significant difference in overall complications in between conventional and percutaneous dilatation tracheostomy group. However, there was no significant difference in terms of total ICU stay, hospital stay and tracheostomy decanulation time in between these group. There was no statistical difference in between individual category of complications in between the two study groups. Conclusion: Percutaneous dilatation tracheostomy is equally safe and effective as conventional tracheostomy but with lower incidence of overall complications and faster to perform.


INTRODUCTION
Tracheostomy is a commonly performed procedure in intensive care units (ICU) to provide a safe airway for patient requiring prolonged mechanical ventilation and secure airway in many neurological and traumatic conditions.Conventional tracheostomy (CT) is one of the oldest surgical procedure existing for more than 3000 years and standardized by Jackson. 1 Intraoperative and postoperative complications like bleeding, cellulitis, stomal infection, etc are quite frequent with CT. Percutaneous dilatation tracheostomy (PDT) has achieved wide acceptance recently since its first introduction by Ciagila in 1985 where dilatation was performed gradually from small to large blunt serial dilators. 2 Later Grigg's modified this technique by adding a guidewire dilating forceps (GWDF), which was similar to modified Howard-Kelly forceps. 3 There are other various techniques of percutaneous Percutaneous dilatational tracheostomy compared with conventional surgical tracheostomy in neurosurgery intensive care unit dilatation techniques used worldwide thesedays all based on seldinger's technique. [2][3][4][5][6][7] In this study, we tried to compare conventional tracheostomy (CT) with percutaneous dilatation tracheostomy using Grigg's GWDF technique in terms of operative timing, duration of ICU and hospital stay and complications.

MATERIALS AND METHODS
A prospective, single blinded, randomized study was done in between April 2019 to December 2019 in patients admitted in neurosurgical intensive care unit (ICU) of Manipal Teaching Hospital, Pokhara, Nepal and requiring tracheostomy. Patient above 18 years of age and requiring tracheostomy were included in the study. Patients were randomly assigned into one of the two groups; group 1 consisted of patients who underwent conventional tracheostomy (CT) and group 2 consisted of those who underwent percutaneous dilatation tracheostomy (PDT). Randomization was done using sequentially numbered, opaque sealed envelopes. After decision of tracheostomy and consent from the relative of the patient, while randomizing the patient, an already sequentially numbered envelope was picked up and the name of the patient was written on the envelope by the ICU sister on duty before opening it. The patient was then allotted to the group according to randomization and the operation team were informed to prepare for either CT or PDT accordingly.
Sample size calculation was done using sample size calculator from www. select-statistics.co.uk. Overall complication of conventional tracheostomy from previous literatures was found to be 36-41% and percutaneous dilatation tracheostomy was found to be 6-12%. 8,9 Thus, keeping sample proportion of group 1 as 38%, sample proportion of group 2 as 9%, confidence interval of 95% and power of 80%, sample size calculated was 30 for each group.
All patients aged 18 or above were included in the study. Patients who did not consent for the surgery or the study, those with history of previous tracheostomy, previous neck surgery, thyromegaly or any neck mass, infection at proposed operative site, extreme obesity and those with unstable cervical spine or in whom neck extension is contraindicated were excluded from the study. Ethical clearance was undertaken from Institutional Review Committee while the study was carried out.
All patients were operated in the operation theatre under general anesthesia by a consultant ENT surgeon or a Neurosurgeon. Percutaneous dilatation tracheostomy was performed using the Grigg's guidewire dilating forceps technique. A horizontal incision of around 1 cm was made approximately 2 finger breadth above the suprasternal notch. The endotracheal (ET) tube was withdrawn gradually by the anesthesiologist till the tip lied just beyond the vocal cord and then the trachea was punctured using a 14-guage needle confirmed by aspirating air on a syringe partially filled with distilled water. At times the needle might puncture the ET tube after puncturing the trachea which can be cross-checked by moving the ET tube in an out gently with the needle in situ. If the needle is embedded in the tube it moves both with to and fro movement whereas if it has not embedded the ET tube it moves only with forward movement of the ET tube (as it hits the needle) and not while backwards movement of the tube. A J-tip guidewire was then inserted through the needle. The stoma was initially dilated with a dilating cannula passed over the guide wire and then a guidewire-tipped dilating forceps (GWDF) was passed through the guidewire into the trachea and the opening was dilated. The process was repeated till an adequate dilatation was achieved. Percutaneous tracheostomy tube of appropriate size with a central lumen in the obturator to allow passage over the guide wire was then inserted and secured inflating the tracheostomy cuff. Guide wire was then removed and tracheostomy position confirmed by auscultation and the ETCO 2 level in the monitor. The ET tube was removed and the tracheostomy tube further secured with sutures and ribbon. Conventional tracheostomy was performed in usual fashion with a 2-3 cm horizontal incision at around two finger breadth above the suprasternal notch. The thyroid isthmus was retracted superiorly, 2 nd tracheal ring was incised and a suitable sized tube was inserted.
Data were recorded in ter ms of demographics, preoperative diagnosis, GCS of the patient at the time of intubation, comorbidities, total duration of ICU stay, total durationhospital stay, decanulation time (time from tracheostomy to removal of tracheostomy tube), operative time and various complications. Operative timewas noted from painting and draping of the operative site to fixing of the tracheostomy tube. Complications were recorded during operation and postoperative period and follow-up at 3 months. Major bleeding was defined as those requiring cauterization or ligation of blood vessels or requiring blood transfusions and surgical exploration postoperatively. Minor bleeding was defined as those controlled by pack dressing with or without epinephrine.
All data are presented as mean and standard deviations for continuous variables and numbers (percentages) for categorical variables. Data were compared using student's t test for continuous variables and Chi-squared test or Fisher's exact test for categorical variables. Data were analyzed using IBM SPSS statistics version 20.

RESULTS
The mean age of the study population was 47.57±18.92 years. There were 34 (43.3%) males and 26 (56.7%) female in the study. The age and gender distribution in both PDT group and CT group along with baseline GCS and comorbidities has been depicted in Table 1. There was no significant difference in terms of baseline status in between the two groups. Figure 1 shows the diagnosis at admission of patients who went tracheostomy in our series. Trauma (25, 42%), cerebrovascular accidents (16, 27%) and aneurysmal subarachnoid hemorrhages (9, 15%) were the commonest admission diagnosis.
Mean operative time in CT group was 35.00±9.56 min and in PDT group was 18.17±8.78 min and the difference was statistically significant (p=0.00). Similarly, there was statistically significant difference in overall complications in between conventional (11,36.7%) and percutaneous dilatation tracheostomy group (4,13.3%) (p=0.03). However, there was no significant difference in terms of total ICU stay, hospital stay and tracheostomy decanulation time in between these groups ( Table 2). Table 3 shows various intraoperative and postoperative complications and their complications in between two groups. Intraoperative major and minor hemorrhage and post-operative major hemorrhage were the most common complications seen in CT group. Post-operative major hemorrhage was seen in 2 (6.7%) cases in PDT group which needed exploration and cauterization in the operation theatre. There were 3 (10%) cases of false track in CT group whereas one (3.3%) cases had false track developed in PDT case intraoperatively. There were no cases of conversion from PDT to CT in our series. Accidental decanulation was more common in CT (3, 10%) group than PDT group (1, 3.3%). Surgical site infection was almost similar in both the groups. There was no statistical difference in between individual category of complications in between the two study groups (Table 3).

DISCUSSION
Tracheostomies are commonly performed procedure in neurosurgical ICU to protect airway from aspiration injuries seen in many neurological conditions, in cases of craniofacial traumas and as an aid in pulmonary toileting and securing airway in cases requiring prolonged mechanical ventilation. 10 Conventional tracheostomy (CT) although has been widely accepted and been in practice for long time but still has many complications, with an overall incidence of 36-41%, including pneumothorax, subcutaneous emphysema, bleeding, tube dislodgements, stomal infections and although very less at times mortality. 9 With the advent of seldinger technique it has been almost replaced by percutaneous dilatation tracheostomy (PDT) in many places. 11,12 PDT on the other hand has reduced incidence of wound infections, clinically significant bleeding, major  In our series, we noted that overall complication was lower in PDT (4, 13.3%) than in CT 11,36.7% and the difference was statistically significant (p=0.03).Overall complications have been reported as 6-12% in literature. 9,13 PDT is considered to be safe procedure in comparison to CT. Many authors even suggest that the complications and clinical outcomes are not of statistical difference in between trainee and experienced surgeon or intensivist. PDT can also be easily picked up by physicians and intensivists working in ICU and well versed with vascular access using Seldinger technique and also be performed bedside. [15][16][17] In our series all the PDTS and CT were performed by consultant ENT surgeons or neurosurgeons and all the PDTs were done in operation theatre as we could have an anesthesiologist taking care of the ET tube and act promptly in case there was any untoward incident of ET tube dislodgement and desaturation during the procedure.
Intraoperative and post-operative major hemorrhage was seen in 5 (16.5%) cases each in CT group where as it was seen in 1 (3.7%) case and 2 (6.7%) cases respectively in PDT group however there was no statistical significant difference. Similarly Intraoperative and post-operative minor hemorrhage was seen in 5 (16.5%) cases and 1 (3.3%) case respectivelyin CT group whereas only 2 cases of postoperative major hemorrhage was seen in PDT group and the difference was not statistically significant. There was no case of minor post-operative hemorrhage seen in PDT group.
The incidences of hemorrhages in CT has been reported up to (3-37%) and is very variable due to the incision and dissection of pretracheal tissue, retraction or division of the isthmus and proximity of the vessels supplying thyroid lying in close proximity to the pre tracheal tissues. PDT on the other hand has been reported to have lesser incidences of hemorrhage mostly owing to small incision, avoiding surrounding vessels if properly planned and done and any small amount of ooze is easily tamponated by the snugly fitted tracheostomy tube and the small incision. Kwon J et al reported minor bleed in CT as 7.0% and in PDT as 4.9%. Similarly they observed moderate to major bleeding in CT as 8.8% and PDT as 1.6 %. Though the incidences of bleeding was less in PDT group, the difference was not statistically significant. 13 Silvester W et al also reported no significant difference in between minor or moderate to severe bleeding in between the two groups. 14 There are evidences of lower incidence of stomal or surgical site infection (SSI) in case of PDT. Our study also shows slightly lower incidences of SSI in PDT group (6.7%) in comparison to CT group (10%) although the difference was not significant statistically. Kwon J et al have observed 1.8% wound infection within 7 days in CT group whereas no infection was reported in PDT group although there was no statistical difference in between the groups. 13 Youssef et al in their study reported 68.5% mild to severe stomal infection in CT group and 12.5 % in PDT group with a statistical significant lower rate of infection in PDT group. 18 A small incision and minimal tissue damage may be the reason of lower stomal infection in PDT group.
Intraoperative desaturation was seen in one case of CT group which was because of false track insertion of tracheostomy tube however no untoward incident encountered. False track was encountered in 3 (10%) cases of CT group and 1 (3.3%) case of PDT group. The false track encountered in both group were pretracheal and could be rectified without any untoward incident. Postoperative accidental decanulation was seen in 3(10%) cases of CT group vs 1 (3.3%) cases of PDT group. No cases of major complications like procedure related death, posterior tracheal puncture in PDT leading to subcutaneous emphysema, pneumothorax or esophageal puncture was seen in our series.
Complications in PDT can be further reduced with increasing experience of the operating surgeon as well as use of preoperative ultrasound to rule out any abnormal course of vessels at the site of cannula puncture as well as enlarged thyroid lobes or the isthmus or any neck masses. 19,20 Use of fiberoptic bronchoscopy can be a useful tool to avoid complications like injury to posterior tracheal wall and esophagus during needle insertion. It might also be useful in teaching and supervision of beginners. However fiberoptic bronchoscope might not be available in all institute especially in developing institute. The free movement of guidewire before each step is considered as prerequisite before proceeding. In our series we did not use fiberoptic bronchoscope but did not encounter any difficulty in completion of PDT and had no cases of conversion to CT. 19,[21][22][23] CONCLUSION Percutaneous dilatation tracheostomy is equally safe and effective as conventional tracheostomy but with lower incidence of overall complications and faster to perform. Intra and post-operative hemorrhages and infections though statistically insignificant but are seen lesser with percutaneous dilatation tracheostomy. It can be a better option in critical care setup where tracheostomy is required and can be performed bedside and even by intensivists and anesthesiologists.