Analysis on 35 Cases of OSAHS Treated by Plasma Ablation Surgery
Xiong Jian, Cai Huacheng (ENT Department of the General Unit of Armed Police Hospital in Sichuan)
Key Words: OSAHS (Obstructive Sleep Apnea Hypopnea Syndrome), Plasma Ablation Surgery Abnormal anatomic form of upper airway is an important pathogenic factor of OSAHS (Obstructive
Sleep Apnea Hypopnea Syndrome). The obstructed areas mainly include nasal cavity and oropharynx. It will cause such main diseases as nosepiece hypertrophy, nasal deviation, rhino polypus, nasosinusitis, tonsil hypertrophy, tongue base hypertrophy, soft palate hypertrophy and sinking, etc. From 2004, Dec to 2008, Mar., our ENT Department has confirmed diagnosis of 35 OSAHS patients and treated them with Plasma Ablation Surgery. The treatment effect is approved. The report is as below.
Subject and Method
Subject: among the 35 patients, there are 28 male and 7 females. Their ages are from 29 to 60 years old, with average of 42 years old. Their chief complaint includes snoring, labored breathing, sleepy, poor memory, headache, etc. For all patients, we have done pre-operative PSG, which showed 14 patients of obstructive type and 21 patients of mixed type. And 14 patients have light condition, 18 patients’ moderate condition, and 3 severe patients. As per Muller examination method, 2 patients belong to I type (The obstructive area is above rhino pharynx), 26 of II type (The obstructive area is at oropharynx, 5 of III type (The obstructive area is at hypopharynx), and 2 of IV type (There are several obstructive areas).
Method: Before surgery, to do regular examinations of Blood Routine, ECG, Chest X-ray, etc. to remove surgical contraindication. After successful local anesthesia, at first to operate surgery for patients with mixed nasal deviation, rhino polypus, tonsil hypertrophy, etc. To use Plasma Ablation System, set the output value at 4 or 5, and do corresponding surgery as per different obstructive areas. For obstructive inferior turbinate, to channel one or two positions at front end of inferior turbinate by using treatment probe. After starting up the ablation switch, to make the treatment probe advance along the long direction of inferior turbinate until reach the back end of inferior turbinate, then the treatment probe continues to work for 8-10 seconds. For obstructive uvula, to channel at the position of 1cm distance from uvula bottom end with channel depth around 0.5CM. To keep the treatment probe to work for 5-7 seconds. For obstructive soft palate, to channel at the position of 1cm distance above the soft palate free margin. To channel 4 or 5 positions at each side with channel depth of 0.5-1.0CM. To keep the treatment probe to work for 8-12 seconds. For obstructive tongue base, to choose 4 or 5 positions around the middle tongue base for channeling with depth of
1.5CM. To keep the treatment probe to work for 10-15 seconds. After plasma ablation surgery, to start up cruor switch to do hemostasis for 10-15 seconds, and then retreat probes slowly. If there is still hemorrhage, to do hemostasis by compressing adrenaline pad or cotton ball. After operation, to do some anti-inflammation and hemostasis treatment.
In 6 months after surgery, patients came back for PSG recheck. As per the standard of 2006 Hangzhou Conference, 10 cases are recovered completely, 15 cases have developing effect, 5 cases
have some effect and 4 cases do not show effect. Thus the total efficiency is 88.57%.
The confirmation of OSAHS patients rely on PSG. As per the guide lines of sleep apnea index, hypopnea index, SPO2 index, and sleep disordered breathing index, etc to judge the patients conditions. There are different plans for different types and conditions. For OSAHS, the tradition method is UPPP surgery. But UPPP causes much suffering, severe hemorrhage and big damages to the pharynx. After UPPP surgery, there may be such complication caused, as pharynx stenosis, food reflux. The UPPP surgery is of high risk and high cost.
Plasma Ablation has been widely applied in ENT clinical field. The main treatment principle of treating OSAHS is as follows: a thin layer of plasma is formed in the soft tissues around the treatment probe. Under a low temperature, the plasma layer makes the ion bonds break. Heat rises in the tissues, and cells disintegrate. Local tissues are coagulated and come into necrosis. Volume of soft tissues is reduced, thus the airway obstruction is removed. For OSAHS patients, Plasma Treatment will make the soft palate contract, improve the soft palate sinking status, make tongue base contract after ablation, make inferior turbinate contract, and widen the nasal cavity. These methods will improve the obstruction condition of upper airway and improve breathing.
We believe that Plasma Ablation System has obvious advantages in treating OSAHS. Plasma ablation only makes the proteins of local tissues coagulated and does not damage the surrounding tissues. It can preserve the physiological functions of mucous membrane of nasopharyngeal. The system can be handled simply and conveniently, easy to be controlled. It brings little hemorrhage during operation, and light post-operative effect. Patients feel little pain and can accept it easily. The operation time is short, with little complications. For some patients, the operation can be done at outpatient clinic. The operation can be done by stages or repeated. Therefore, this deserves to be promoted in clinical field.
Doghranji R, Jabourian ZH, Pilla M et al. Predictions of outcome for uvulopalatopharyngoplasty. Laryngoscope, 1995,105:311-314
ENT Branch of Chinese Medieal Association and Chinese ENT Editor. Standard of Diagnosis and Treatment Effect Judge for OSAHS and UPPP Indication (Hangzhou). Chinese ENT Magazine, 2002, 37 (6):403-404
Wang Pengju and Li Renji. UPPP Complications and Prevention. Clinical ENT Magazine, 2001, 15(12):563-564
Ji Xuezhi, Guo Liu, Sun Fangqing, etc. 41 Cases of OSAHS Treated by Low-temperature Plasma Ablation Surgery. Armed Police Medical Science, 2004, 15(10): 7779-780.
Liu Jun, Zhang Bo, Yang Xiaoping, etc. Effect Observation of 48 Cases of Chronic and Hypertrophic Rhinitis Treated by Low-temperature Plasma Treatment under Endoscope. Armed Police Medical Science, 2005, 16 (4):281.
Brief Introduction of Author: Xiong Jian, male, born in 1975. Bachelor’s degree, Attending Doctor. Mainly engaged in clinical diagnosis and treatment of dental, nose and throat diseases.
Comparison Between Ablation & Coagulation-Assisted Tonsillectomy Versus Conventional Tonsillectomy Regarding the Postoperative Pain and Bleeding
Stefan Konsulov1, Spas Konsulov2, Karen Dzhambazov2, Petar Kopanov3
1Department of Ear Nose and Throat Disease, University Hospital Kaspela, Medical Univesity-Plovdiv, Plovdiv, Bulgaria 2Deaprtment of Ear Nose and Throat Disease University Hospital St. George Plovdiv, Medical University-Plovdiv, Plovdiv, Bulgaria 3Faculty of Mathematics and Information, University of Plovdiv Paisii Hilendarski, Plovdiv, Bulgaria
Received: March 27, 2017; Accepted: April 5, 2017; Published: April 26, 2017
Abstract: Background: The tonsillectomy is one of the most common surgical procedure in the world. Common complications are postoperative pain and bleeding. Ablation & Coagulation tonsillectomy is recent method of these surgical procedure and there are few publications in the literature and published information which are focused on the specific aspects of this surgical techniques or early postoperative complications. This study compares Ablation & Coagulation and traditional tonsillectomy techniques in view of their advantages and complications. methods: In our prospective study type we include 60 children and adolescents, divided equally:30 conventional tonsillectomy versus 30 surgically treated with PLA700 system by MECHAN (Mechan Europe Ltd). We compared the postoperative pain and intraoperative bleeding in the patients underwent surgery within conventional method versus Ablation & Coagulation assisted tonsillectomy. To measure the pain, we used visual-analogue scale of Wong-Baker with face expressions (0 no hurt; 10-hurts worst). We follow-up the level of pain in the day 1,2 and 7 after the surgery Estimated blood loss for Ablation & Coagulation tonsillectomy was calculated by deducting the total amount of blood in suction jar with estimate saline used for the surgery. Results: Average age of participants surgically treated with conventional method group are 6,87±3,01. In the group where we used Ablation & Coagulation method the average age of participant was 8.16±4,74. We found statistically significant differences (p-value<0.0001) in these parameters in both surgical techniques: the pain is less weak in intensity in the patients treated with the Ablation & Coagulation method in all the three days. In regard of intraoperative bleeding we found statistically significant difference between both methods (p-value -9.3132*10-10). The average bleeding in the conventional method is 97,5 ml ±12,12 ml, comparing with the Ablation & Coagulation -assisted tonsillectomy the average intraoperative bleeding is 27,1 ml ±14,28 ml. Conclusions: This study revealed a significantly less intraoperative or postoperative complications and morbidity in Ablation & Coagulation tonsillectomy in comparison with traditional method. Ablation & Coagulation was associated with less pain and quick return to normal diet and daily activity. These findings addressed Ablation & Coagulation tonsillectomy as an advanced method.
Keywords: Plasma Technology, Ablation & Coagulation, Tonsillectomy, Complications
Tonsillectomy is one of the most common surgical procedure in Bulgaria performed by the ENT surgeons. Most literatures mentioned that the tonsillectomy operation is one of the most common major pediatric surgical intervention with recorded of mortally and also morbidity. In Germany every 25th patient, who underwent tonsillectomy are reported with postoperative bleeding. Reports for complications and even death equally disturb patients and Surgeons. One of the most common complaint after tonsillectomy is postoperative pain. Postoperative pain makes the recovery process more difficult and slower in time. The patients can’t start eating and drink early after the surgery especially children.
[1, 2, 3, 5, 7, 14, 15, 16, 18]
Ablation & Coagulation
A minimally invasive, low thermal technology for effective dissection and removal of soft tissue, Ablation & Coagulation technology is ideal for such ENT procedure as Tonsillectomy, Adenoidectomy, Reduction of Hypertrophic Nasal Turbinates, Laryngeal Polypectomy and Lesion Debulking, Soft Palates, Snoring and Sinus Surgery. While the most radiofrequency- based on surgical products, such as laser and electrosurgical devices, use imprecise heat-driven process to remove or cut tissue, Ablation & Coagulation Plasma technology creates a controlled, stable plasma field to precisely remove tissue at a low relative temperature, resulting in minimal thermal damage to surrounding tissues [1, 7, 13].
The Ablation & Coagulation method is a surgical technique of Ablation & Coagulation tonsillectomy is based on bloodless dissection in the tonsillar field by using MECHAN’s PLA401 (EB401M07-1 / EB401M07-5 / EB401M07-5) wands.
Tonsillectomy, Adenoidectomy, UPPP, CAUP Wand. Using this technique, it has found practically bloodless field through the surgery procedure and the overall blood lost is not significant. [1, 4, 8]
Blackburn and Ribble Valley Health Authority own the biggest tonsillectomy record with PLA700 Plasma Surgery Set in UK and probably the biggest in the world, approximately 850 cases. Using these data, we can calculate the complications followed this new surgical procedure and compare it with our standard method of tonsillectomy. Secondary complications or bleeding are due to infections in the tonsillar field. The contractions of the pharyngeal muscles are responsible for physiological cleaning of tonsillar field and also the infections can be caused by the contamination with food in that area. The muscular failure due to severe pain or volitional immobilization are obstacles in physiological cleaning of the tonsillar field. This increased the chances to develop infection and bleeding after that. Considering secondary bleeding, Ablation & Coagulation tonsillectomy is more reliable comparing to the dissection tonsillectomy. The advantages of this technique are: low level of postoperative pain and discomfort, early return to normal diet physical activities and also small amount intraoperative blood loss. Therefore, the postoperative period is shorter than conventional method and also better postoperative quality of life. [3, 14, 17]
2.Aim of the Study
Establishment of Ablation & Coagulation assisted tonsillectomy as a routine surgical method in children with chronic tonsillitis or tonsillar hypertrophy and OSA.
This study is prospective and comparative, involving 60 children in the age of 3-18y. The patients were divided into groups on equal basis according to the surgical technique- Group 1 and Group 2. This study on 60 people was performed in the period of 2014-2017. The project was approved with protocol of ethic commission in the Medical University of Plovdiv. The children were included in the study after the consent form was sign by the Parents.
Including criteria: Paradise criteria for tonsillectomy 
Minimum frequency of sore throat episodes-7 or more episodes in the preceding year, OR 5 or more episodes in each of the preceding 2 y 3 or more episodes in each of the preceding 3 y
Clinical features (sore throat plus the presence of one more qualifies episodes as a counting episode: Temperature > 38.3°C, OR 101°F
Cervical lymphadenopathy (tender lymph nodes or >2 cm), OR Tonsillar exudate, OR Positive culture for group A b-hemolytic streptococcus
Bad breath, which may relate with cryptic tonsils
Enlarged and tender neck lymph nodes
Hypertrophy-causing upper airway obstruction (obstructive sleep apnea)
Ever, dysphagia (trouble swallowing), sleep disorders, or cardiopulmonary
Excluding criteria: different age group
Very young age under 4
Presence acute infection
Refusal of surgery
Unilateral tonsillar hypertrophy
Known blood disease
On the day of admission, the patients were examining by ENT specialist and history was taken. They were questioned about any current acute diseases, any history of blood disease in the family, any known allergies, medication and opioid medication also ongoing menstrual cycle in older female patients at the day of admission. The venous blood was taken from the patients and sent in the laboratory for full blood count and time of bleeding and coagulation. After the blood results the patients were referred to pediatric department and anesthetist for consultation and general anesthesia. All the patients and parents were informed about the upcoming surgery, benefits and further complication were discussed, after that they sign a consent form.
The conventional method includes extra capsular blunt dissection with bipolar diathermy for haemostasis. In the Ablation & Coagulation tonsillectomy we used PLA700 (by Mechan Europe) PLA401 wand for extracapsular dissection with also irrigation and haemostasis. We evaluate the objective and subjective complaints by using questionnaire form and visual analogue scale of Wong- Baker with facial expression, for both methods Ablation & Coagulation - assisted tonsillectomy and conventional method 0- no hurt, 10 hurt worst.
General anesthesia was used for all the patients in this study.
Estimated blood loss for Ablation & Coagulation tonsillectomy was calculated by deducting the total amount of blood in suction jar with estimate saline used for the surgery.
The estimate blood loss for conventional tonsillectomy was calculated by deducting the total amount of blood in suction jar.
Postoperative bleeding- early bleeding to 24h after the surgery and late bleeding after 24h. In the morning ward round 8-9h O’clock we examined the wound, the overall condition of the patients and any history of bleeding. All the data were correctly filled. Any events of postoperative bleeding were reported in the study. We used combination of paracetamol and ibuprofen with the appropriate dosage for around a week if needed.
Healing of the wound was reviewed and on the 1st, 2nd and 7th day. We were reviewed the postoperative wound and measured the fibrin deposits.
All the patient who were admitted for tonsillectomy in University Hospital St. George, Plovdiv and University Hospital Kaspela, Plovdiv stayed in the ward minimum for two days. All the patients who were in good overall condition start to eat and drink in the evening after the surgery have no signs of bleeding were discharged at the second day after the surgery. All the patients were coming in outpatient clinic on the 7th day after the surgery to be followed up (measure the pain and postoperative wound). The statistical analysis was based on ‘’sign test’’ and have done by using Mathematica Version 11.
The patients who were included in the study were 60 and divided on two equal groups:
30 people with conventional dissection tonsillectomy versus 30 patients who were surgically treated with Ablation & Coagulation method. The average age of patients was 6,87±3,01 in the group one. In the second group where we used PLA700 & PLA401 wand average age was 8,16±4,74. There weren’t any early or late bleeding in the group of Ablation & Coagulation assisted tonsillectomy, there were two cases with
postoperative bleeding in the group of conventional method.
Regarding the pain: on the first day after the surgery in conventional method we have average level of pain 7,4±0,93 according to the Wong-Baker pain scale. The Wong-Baker FACES Pain scale is often helpful for assessing persons with moderate to severe dementia or children who have lost much of their ability to use language to describe pain. This scale uses faces from happy to tearful to demonstrate how a person might be feeling. It should be used only after the person in pain has demonstrated inability to understand the “0” to “10” pain scale .
The patients who were surgically treated with the conventional method received ibuprofen and paracetamol for around a week.
On the second day after the surgery with the same method the level of pain was 5,66±0,92. On the seven day was 3,86±1,47. Regarding to Ablation & Coagulation assisted tonsillectomy the average level of pain on the 1st day was 2,6±1,19. On the second day the level of pain was 3,06±1,48. On the 7th day the pain was 2,2±1,27. (figure 1). Few hours after the surgery the patients received ibuprofen and paracetamol after that in most cases the pain regressed spontaneously.
Table 1. Average values on the basic indicators in the both surgical methods; Group1 - Cold steel dissection tonsillectomy; Group2 - Coblator assisted tonsillectomy.
There are statistically significant differences in the conventional versus Ablation & Coagulation tonsillectomy regarding the: 1st day pain (p-value- 9.3132*10-10), 2nd day pain (p-value- 7.4505*10-9) and 7th day pain (p-value- 0.00006); Regarding the pain on the 1st day and 2nd day the values are so small that we should exclude the chance possibility. The conclusion shows that the two methods are significantly different, and these results are not due on chance. They are resulted on two different methods.
Regarding the intraoperative bleeding there is statistically significant difference between both methods (p-value - 9.3132*10-10) Avarage blood loss in the conventional method is 97,5 ±12,13 ml and 27,1±14,28 ml in the Ablation & Coagulation assited tonsillectomy.
Figure 1. Postoperative pain on the 1st day comparing conventional tonsillectomy and Ablation & Coagulation -assisted tonsillectomy.
Pain on the 1st day after the surgery is significantly less weak as feeling in the Ablation & Coagulation group vs the conventional tonsillectomy group.
Figure 2. Postoperative pain on the 2nd- day comparing conventional tonsillectomy and Ablation & Coagulation -assisted tonsillectomy.
Figure 3. Postoperative pain on the 7th- day comparing conventional tonsillectomy and Ablation & Coagulation -assisted tonsillectomy.
Figure 4. Intraoperative bleeding comparing both methods.
Intraoperative bleeding is significant less in the patients on who were performed surgery with PLA700 PLA401 wand comparing with conventional method.
Tonsillectomy is one of the most common surgery procedures performed in Bulgaria. The tonsillectomy surgery is commonly the first surgery ever in childhood. It is commonly be related with different type of complications. Postoperative pain can lead to difficult intake of food and liquids which therefore can delay the healing of the wound and prolonged the restorative period. Postoperative bleeding is very serious complication and even can lead to death. Bleeding in the throat can hide a high risk of aspiration especially in children or even developing hemorrhagic shock
[1, 4, 8].
In this study the postoperative pain in patients who undergoing Ablation & Coagulation assisted tonsillectomy have a significantly low pain on the 1st, 2nd and 7th day comparing with conventional method. The average pain score in all three days between both groups have a significant difference. The patients who were treated surgically with the Ablation & Coagulation method on the 1st postoperative day have 4,8 points lower pain on the 2nd day 2,6 points lower pain and 1,64 points on the 7th day according to the Wong-Baker visual analogue scale. In 2012 Wagner and assistant conduct the same study in the ‘’Alfred Krupp von Bohlen und Nalbach’’Krankenhaus in Essen Germany on 376 Patients with (conventional tonsillectomy) and 94 patents who were surgically treated with Ablation & Coagulation method. The average age was 15,6 y in the control group and 15,7 y in the other group. The significant lower postoperative pain was observed in the Ablation & Coagulation group versus conventional tonsillectomy (0,9 vs 6,4 points according to the visual analogue scale). In the Wagner study they found postoperative bleeding in 5,32% of the patients who undergoing Ablation & Coagulation tonsillectomy and 5,05% postoperative bleeding with the conventional method. There wasn’t statistically significant difference in both groups comparing this indicator (p=1.00) (16) the same as our study. We have in mind all the possible reasons that can cause a postoperative bleeding: postoperative pain, postoperative infection. .
Regarding postoperative bleeding in the group of conventional method there were only two cases with bleeding which were treated conservatively in the ward with antibiotics and pain killer due to suspicious of postoperative infection. In the other group where we used Ablation & Coagulation method we didn’t have postoperative bleeding. There wasn’t statistically significant difference regarding these two factors in both groups.
Polites et al. are measured postoperative pain into 19 patients on age between 16 y and 41 y and have found that postoperative pain on the first day was 3 points lower by using Ablation & Coagulation method. On the 2nd and 3th day the pain was also significantly lower. They measured the pain using visual analogue scale. .
In 2006 Noordzij et al. are measured postoperative sense of pain into 48 adult patients who were surgically treated with PLA700 & PLA401 wand (Mechan Europe) and monopolar electrocautery. In this study they also found a significant lower pain in the Ablation & Coagulation method with 2 points lower pain comparing with the other group. Fourteen days after the surgery the postoperative pain was also significant lower in the group of Ablation & Coagulation comparing to the other group. This study have similar results regarding the Ablation & Coagulation tonsillectomy. .
In 2007 Mitic et al. performed prospective single blind, randomized controlled trail including 40 patients on the age between 4y-12y (16-60 kg) with Ablation & Coagulation tonsillectomy and dissection tonsillectomy with bipolar diathermy haemostasis. Primary outcomes were scored for postoperative pain, nutrition, activity and use of analgesia for each of the 10th postoperative days. The groups were statistically comparable by age weight and operation type. Intraoperative bleeding was significantly less in the Ablation & Coagulation group. We can confirm that we have similar results regrading intraoperative bleeding where we have approximately 70 ml less blood loss in the Ablation & Coagulation group comparing with the conventional group method. .
Mohammadreza et al. are conduct double-blind randomized study type case-control in the period of 2007- 2008 with PLA700 MECHAN Surgery Set and conventional method. They have found statistically significant difference regarding the postoperative pain. (p-value<0.01). In regard of postoperative bleeding they haven’t found any significant difference between the two groups. . In our results we can confirmed the same findings such as this study .
In regard of intraoperative bleeding they have found statistically significant difference (p<0.05), between both methods in favor of Ablation & Coagulation -assisted tonsillectomy the same as our results.
In our study we have found, that Ablation & Coagulation assisted tonsillectomy is less harmful and effective alternative method versus the traditional dissection tonsillectomy. Ablation & Coagulation assisted tonsillectomy comparing with the other methods do not lead to deep burning or damaging of surrounding tissues, which is not predisposing factor for postoperative infection and bleeding. Thus, significantly reduce the postoperative pain, lead to better postoperative life quality, faster recovery and healing of postoperative wound.
Георгиева Н., Златанов Хр., Цветков В. Тонзилектомия – съвременни оперативни техники. Международен бюлетин по оториноларингология, 2012, 1:19
Balbani APS. Personagens da História da Otorrinolaringologia. Arq. Int. Otorrinolaringol. 1998; 2(2):54.
Blakley BW, Magit AE. The role of tonsillectomy in reducing recurrent pharyngitis: a systematic review. Otolaryngol Head Neck Surg. 2009; 140: 291-297.
Burton MJ, Doree C. Coblation versus other surgical techniques for tonsillectomy. Cochrane Database Syst Rev. 2007; 18(3): CD004619.
Haddow, K., M. L. Montague and S. S. Hussain (2006). "Post- tonsillectomy haemorrhage: a prospective, randomized, controlled clinical trial of cold dissection versus bipolar diathermy dissection." J Laryngol Otol 120(6): 450-4.
Hockenberry MJ, Wilson D, Winkelstein ML: Wong's Essentials of Pediatric Nursing, ed. 7, St. Louis, 2005, p. 1259.
Johnson LB, Elluru RG, Mayer III CM. Complication of adenotonsillectomy Laryngoscope 2002;112:35-37.
Kay DJ, Mehta V, Goldsmith AJ: Perioperative adeno- tonsillectomy management in children: Current practices. Laryngoscope 113:592-597, 2003.
Mohammadreza O, Behrouz B, Navid O, Ahmad RO, Seyed A, Ghazizadeh H, Coblation versus traditional tonsillectomy: A double blind randomized controlled trial. J Res Med Sci. 2012 Jan; 17(1): 45–50.
Mitic S, Tvinnereim M, Lie E, Saltyte BJ. A pilot randomized controlled trial of coblation tonsillectomy versus dissection tonsillectomy with bipolar diathermy haemostasis. Clin Otolaryngol. 2007; 32(4): 261-7
Noordzij JP, Affleck BD, Coblation versus unipolar electrocautery tonsillectomy: a prospective, randomized, single-blind study in adult patients. Laryngoscope. 2006 Aug;1 16(8):1303-9.
Paradise JL: Tonsillectomy and adenoidectomy. In Bluestone CD, Stool SE, Alper CM, et al (eds): Pediatric Otolaryngology 4th ed. Philadelphia, W. B Saunders:1210- 1222, 2002
Polites N, Joniau S, Wabnitz D, Fassina R, Smythe C, Varley P, Carney AS. Postoperative pain following coblation tonsillectomy: randomized clinical trial. ANZ J Surg. 2006; 76(4): 226-229.
Temple RH, Timms MS. Paediatric coblation tonsillectomy. Int J Pediatr Otorhinolaryngol. 2001; 61(3):195–8.
Weir N. History of Medicine: Otorhinolaryngology. Postgrad. Med. J. 2000;76:65-69.
Wagner J, Einfluss des Coblation®-Verfahrens bei der Tonsillektomie auf die Häufigkeit von Nachblutungen und postoperativen Schmerzen, Dissertation zur Erlangung des Grades eines Doktors der Medizin der Medizinischen Fakultät der Heinrich-Heine-Universität Düsseldorf, Hals- Nasen- Ohren- Klinik der Heinrich-Heine-Universität Düsseldorf, Germany.
Windfuhr JP, Chen YS, Remmert S. Hemorrhage following tonsillectomy and adenoidectomy in 15,218 patients. Otolaryngol Head Neck Surg. 2006; 132:281-286.
Young J. R, Bennett J. History of Tonsillectomy. ENT News. 2004;1 3:34-35.