Benchmarking surgery: secondary post-tonsillectomy hemorrhage 1999–2005

Conclusions. We found no evidence that the reported increase in otolaryngologic surgery in Norway in recent years has affected post-tonsillectomy hemorrhage rates, and suggest that the latter is a valuable benchmark for the quality of the tonsillectomies and adenotonsillectomies nationwide. Objectives. To estimate the incidence of post-tonsillectomy hemorrhage and assess the distribution of hospitalizations for post-hemorrhage bleeding and surgery. Materials and methods. This was a national study using data from the Norwegian Patient Registry 1999–2005 with complete information on the incidence of post-hemorrhage hospitalizations, rebleeding surgery, and (adeno)tonsillectomy rates. Results. One patient per 200 tonsillectomies was hospitalized and 1 per 1000 operated for post-tonsillectomy hemorrhage during the study period. Of the 328 patients hospitalized, 64 (20%) required surgery under general anesthesia. Peak age was 5–9 years; 194 (59%) with post-tonsillectomy hemorrhage were males. The mean rebleeding rate was 0.5% (confidence interval (CI)=0.5–0.6) when secondary rebleeding was estimated as the proportion of all tonsillectomies. While tonsillar surgery was more frequent in the non-adult population, post-tonsillectomy surgery was equally common in the ages below and above 16 years. Seasonal variation in post-tonsillectomy hemorrhages was not found.     

Rate of post-tonsillectomy hemorrhage after elective bipolar microcauterization of nonbleeding vessels

The objective of this paper is to describe an extended microscopic hemostasis technique involving cauterization of exposed blood vessels that were not actively bleeding in tonsillar fossa after bipolar tonsillectomy and to assess the rate of post-tonsillectomy hemorrhage with this technique in children who had bipolar tonsillectomy. The medical records of children who underwent microscopic bipolar tonsillectomy with extended hemostasis between June 2008 and January 2011 were reviewed. Relevant history and physical examination, diagnosis, and characteristics of postoperative hemorrhage were recorded; 994 children (531 males, 463 females), aged between 1 and 18 years (6 ± 3 years), underwent tonsillectomy; of the 994 patients, 11 (1.1%) developed post-tonsillectomy hemorrhage. No primary post-tonsillectomy hemorrhage occurred. The hemorrhage was seen 6–13 days after the surgery. One patient had bleeding after having trauma to the neck on postoperative day 13. Of the 11 patients with post-tonsillectomy bleeding, 3 had blood clot with no active bleeding and 8 exhibited active bleeding after removal of blood clot. Of the 994 patients, 8 (0.8%) needed intervention to control active bleeding. Compared to previous studies of bipolar tonsillectomy, extended microscopic hemostasis achieved by cauterization of tonsil fossa non-bleeding blood vessels appeared to reduce bleeding rate after bipolar cautery tonsillectomy. The present study did not include a control arm; further randomized controlled studies are needed to establish the definite effect of extended microscopic hemostasis technique on the rate of hemorrhage rates after tonsillectomy techniques.     

A prospective study on pros and cons of electrodissection tonsillectomy

OBJECTIVE: Hemorrhages are main complications after tonsillectomy, whatever technique is used. This prospective study aimed at revealing pros and cons associated with monopolar electrodissection tonsillectomy. STUDY DESIGN: A prospective study. METHODS: A prospective study on all patients undergoing tonsillectomy or adenotonsillectomy in Central Hospital of Central Finland in 1997. Operation time and bleeding, as well as perioperative and postoperative complications, were recorded. RESULTS: Inpatient tonsillectomy was performed in 440 patients (mean age, 17.9 y). Primary post-tonsillectomy hemorrhage (within 24 h) occurred in 2.3%. A total of 15.9% of patients searched for medical help because of secondary post-tonsillectomy hemorrhage, 7.7% receiving active treatment and 8.2% not. Post-tonsillectomy hemorrhages proved to be most common in older patients and when peritonsillar abscess was in patient history. CONCLUSIONS: Monopolar electrodissection tonsillectomy was fast and resulted in little intraoperative bleeding. However, postoperative hemorrhages were common, and the mean use of analgesics was for more than 10 days. Preoperative counseling must be thorough and realistic. Our results indicate that better methods for tonsillectomy still need to be developed.     

儿童扁桃体切除术后出血率及出血程度分级的初步探讨

目的　统计儿童扁桃体切除术后出血率,根据Windfuhr分级法衡量儿童扁桃体术后出血的程度。方法 统计2010年3月～2013年3月在深圳市儿童医院行扁桃体切 除或扁桃体加腺样体切除患儿资料,统计术后出血发生率。结果　1672例患儿扁桃体切除术后出血16例,出血率为0.96%。女童术后出血率1.8%明显高于男童出血率0.53%,差异有统计学意义（χ 2=5.545,P <0.05）;原发性出血6例,继发性出血10例。出血程度1级9例,2级7例。结论 儿童扁桃体切除术后出血率很低,遇有活动性出血者应手气管插管全麻下止血。     

Hemorrhage rate after coblation tonsillectomy: a meta-analysis of published trials

After the surgical procedure of tonsillectomy, hemorrhage ranks among its serious postoperative complications. In this systematic review, we analyze hemorrhage following tonsillectomies performed using the coblation technique. 24 prospective, randomized, and controlled studies were included in the meta-analysis. Data of 796 patients who had undergone coblation tonsillectomy were analyzed. Hemorrhages occurred in 33 patients: 2 classified as primary and 26 as secondary hemorrhages. 5 could not be classified into either group. Overall, the total hemorrhage rate for the coblation procedure was 4.1% with a 95% confidence interval from 2.8 to 5.5%. The overall hemorrhage rate of 4.1% found in this meta-analysis shows that coblation is a safe and effective technique for tonsillectomies with a secondary bleeding rate similar to what is reported for comparable techniques such as bipolar diathermia.     

Post-tonsillectomy and adenoidectomy hemorrhage

This is a retrospective review of 6842 tonsillectomies and adenoidectomies performed over a seven-year period at the Montreal Children's Hospital. The total incidence of postoperative bleeding was 2.5%. The incidence of primary post-tonsillectomy hemorrhage was 1.0%, with 78% of these children having developed bleeding within 12 hours of surgery. The overall incidence of secondary post-tonsillectomy hemorrhage was 1.2%. Twenty-nine percent of children with primary hemorrhage required a second general anesthetic, and 40% required blood component transfusion. Eight percent of children with secondary hemorrhage required a second general anesthetic and 24% received transfusions. Based on these findings, primary and secondary hemorrhage can be classified further into major and minor. The criteria for a major post-tonsillectomy hemorrhage are: requirements of a general anesthetic to control and repair the bleeding, or blood loss that is sufficient to require blood component transfusion therapy. The relevance of these findings with regard to outpatient adenotonsillectomies is discussed.     

Postoperative bleeding after diathermy and dissection tonsillectomy

OBJECTIVE: To analyze the incidence and pattern of bleeding after tonsillectomy performed by either cold dissection or diathermy. DESIGN: A prospective, nonrandomized cohort study of postoperative hemorrhage after tonsillectomy. METHODS: Monthly reporting of the number of tonsillectomies and postoperative bleeds from otolaryngologists working in rural areas of Victoria, Australia over a 2.5 year period. Criteria for bleeding were either 1) repeat anesthesia and surgery because of hemorrhage (including return to theater from the recovery room), or 2) readmission to hospital because of bleeding, or 3) blood transfusion to replace blood loss. Main outcome measures were the incidence, volume, and time course of postoperative hemorrhage. RESULTS: The number of bilateral tonsillectomies with removal by cold-blunt dissection was 3,087. In this group, there were 57 (1.85%) bleeds. The number of bilateral tonsillectomies with removal by diathermy dissection was 1,557. In this group, there were 37 (2.38%) bleeds. If cold dissection is taken as the "control" and diathermy tonsillectomy as the "treatment" group, the relative risk of bleeding after diathermy tonsillectomy is 1.30 (95% confidence interval 0.88-1.93). The pattern of bleeding after each technique differs significantly over time, with more reactionary bleeds in the dissection group and more bleeds between 4 to 7 postoperative days after diathermy. When bleeding occurred, it was in excess of 500 mL in 16% of dissection cases and 43% of diathermy tonsillectomies. CONCLUSIONS: The difference in the risk of bleeding after each technique did not reach statistical significance, but the temporal pattern of hemorrhage differed, and more bleeds exceeding 500 mL were seen in the diathermy group.     

Post-tonsillectomy hemorrhage: incidence, prevention and management

Tonsillectomy (with or without adenoidectomy) continues to be a commonly performed operation in the United States. Over the years, the incidence of post-tonsillectomy hemorrhage (reported between 0% and 20%) has decreased, but continues to pose serious problems. We reviewed 1,445 tonsillectomies performed over a 2-year period to study the incidence of post-tonsillectomy hemorrhage. Thirty-eight of 1,445 children (2.62%) had postoperative bleeding. The incidence of primary hemorrhage (within 24 hours) was 0.14%. Delayed hemorrhage requiring operative intervention or observation in the hospital was 1.03% and 0.76%, respectively. Ten patients (0.69%) had delayed hemorrhage of a minor nature that had stopped by the time they reached the hospital; these children were treated with observation alone and did not require hospitalization or operative intervention. The proposed reasons for this low rate of post-tonsillectomy hemorrhage include complete preoperative coagulation screening, meticulous attention to surgical technique, use of suction-cautery to obtain hemostasis and, possibly, use of postoperative antibiotics. Management of hemorrhage is discussed with respect to observation, surgical intervention, and blood transfusion.     

Day case paediatric tonsillectomy: a review of three years experience in a dedicated day case unit

Tonsillectomy is one of the most common surgical procedures performed in children. Day case tonsillectomy is common in many parts of the USA but remains controversial in the UK. Day case tonsillectomy in children has been performed in a dedicated paediatric day care unit at the Mayday Hospital since 1994. The results for the years 1995–1997 were reviewed. In these years 928 true day case tonsillectomies were performed. Reactionary haemorrhage occurred in 0.97% (nine children) but only three children required a return to theatre. All bleeding occurred within the standard observation period. There were no deaths. The overall effective day case rate was 95.7%, only 31 children needing unplanned admission, mainly for postoperative vomiting. The results suggest that day case tonsillectomy can be safely and successfully performed, with a dedicated paediatric day case unit and a favourable population geography.     

Lethal post-tonsillectomy hemorrhage

Background: Post-tonsillectomy hemorrhage (PTH) seems to be a rare but unavoidable complication. Due to the frequency of performed tonsillectomies, it can be estimated that a certain amount may result in a lethal outcome. This study was undertaken to evaluate the clinical features of these rare cases. Material and methods: Retrospective case series of five patients with lethal post-tonsillectomy hemorrhage are reported after they had undergone tonsillectomy by four different surgeons. The relevant literature was reviewed. Results: The youngest patient was 42 months and the oldest almost 13 years old. All patients were male. Three patients had left the hospital against surgeon’s recommendation 5 days following tonsillectomy. Preceding episodes of bleeding prior to the lethal bleeding occurred in two patients. Lethal PTH occurred in four patients within 5–9 days, the latest bleeding 39 days after surgery. In the literature, lethal PTH was described for eight patients since 1958. The youngest patient was 4 years, the oldest 18 years old (mean: 8.6 years; median: 6.5 years). In three patients, lethal PTH occurred on the day of surgery and the latest bleeding 54 days after surgery. Conclusion: Due to the paucity of reports, little reliable information can be obtained from the literature. It remains unclear, whether or not this reflects the true incidence of this complication. The experience with the five reported cases suggests, that immediate surgical treatment may have avoided lethal outcome in most cases. Therefore, a close postoperative follow-up is advisable to detect any episode of bleeding as soon as possible which should be referred to a specialist. Certainly, the collected data do not suffice to establish general guidelines, indicating that further collection of cases is required to assess characteristics of lethal PTH.     

Tonsillectomy: cold dissection versus bipolar electrodissection

OBJECTIVES: to compare the technique and post-operative morbidity of two different tonsillectomy methods: cold dissection and bipolar electrodissection. MATERIAL AND METHODS: prospective study including children (3> age <14) undergoing tonsillectomy in ORL Department of the main hospital in Azores, Portugal, from September 2000 to March 2001. Patients alternately selected to cold dissection tonsillectomy group (CDT) or bipolar electrodissection tonsillectomy group (BET). Duration of surgery; amount of blood loss; duration of hospitalization; aspect of tonsillar fossa on 10th post-operative day and intensity of pain after surgery were recorded and compared. RESULTS: Sixty tonsillectomies were performed. Blood loss and duration of surgery were significantly decreased in BET group (P<0.001), but the healing process, directly assessed by the aspect of tonsillar fossa on the 10th day was markedly delayed. The intensity of pain was slightly higher in the BET group compared with the CDT group, and no difference on duration of hospitalization was found between the two groups. Two post-operative hemorrhages occurred (one in each group), and no major complications were registered. CONCLUSIONS: BET reduces the duration of surgery and amount of blood loss when compared with cold dissection, but post-operative morbidity is increased. We believe the best patient indication for this method are small children where total circulating blood volume is reduced and patients with bleeding disorders.     

Day case paediatric tonsillectomy: a review of three years experience in a dedicated day case unit.

Tonsillectomy is one of the most common surgical procedures performed in children. Day case tonsillectomy is common in many parts of the USA but remains controversial in the UK. Day case tonsillectomy in children has been performed in a dedicated paediatric day care unit at the May day Hospital since 1994. The results for the years 1995-1997 were reviewed. In these years 928 true day case tonsillectomies were performed. Reactionary haemorrhage occurred in 0.97% (nine children) but only three children required a return to theatre. All bleeding occurred within the standard observation period. There were no deaths. The overall effective day case rate was 95.7%, only 31 children needing unplanned admission, mainly for postoperative vomiting. The results suggest that day case tonsillectomy can be safely and successfully performed, with a dedicated paediatric day case unit and a favourable population geography.     

Immediate abscess tonsillectomy — a safe procedure?

Objective: Peritonsillar abscess is the most common infection involving deep neck planes to be treated by otolaryngologists with varying management strategies. In some countries, like Japan, immediate tonsillectomy is considered only for selected cases due to the risk of post-operative complications. Post-tonsillectomy bleeding is considered as the major complication following surgery and serves as a landmark for the safety of the operation. The purpose of this study was to evaluate if there is an increased risk of post-tonsillectomy haemorrhage following immediate tonsillectomy in non-selected patients. Methods: A retrospective study was performed on 6329 patients who underwent tonsillectomy, with or without adenoidectomy, in St. Anna Hospital, Duisburg, between January 1988 and August 2000 to evaluate the complication rate following 1481 immediate tonsillectomies (group A) compared to 4848 patients who underwent elective tonsillectomy (group B). 56.9% (group A) were male, the youngest patient was 18 months, the oldest 87 years old. Patients of group B were younger in general (mean age: 18.7 vs. 32.9 years), 49.9% were male, between 5 months and 93 years of age. Patients of both groups underwent surgery under general anaesthesia and were observed for 6 days. The incidence of post-tonsillectomy haemorrhage in both groups was compared using χ²-test, the age distribution was compared by Mann-Whitney U-test. Results: Bleeding occurred in 43 patients of group A (2.9%) and 138 patients (2.8%) of group B. Excessive bleeding requiring ligature of the external carotid artery became necessary in one patient of group A (0.13%) and four patients of group B (0.08%). A 42-month-old patient (group B) died due massive haemorrhage at home 6 days after surgery. The latest bleeding occurred 12 (group B) and 13 days (group A) after surgery. Statistical evaluation (Pearson χ²-test P=0.908) shows no significant difference of post-operative bleeding between the compared groups. Post-tonsillectomy haemorrhage occurred with statistical significance (P<0.001) in elder patients after immediate tonsillectomy. Conclusions: We conclude, that immediate tonsillectomy can be recommended as a safe surgical procedure in non-selected patients to evacuate quinsy without an additional risk of bleeding thus making a second hospital stay unnecessary.     

Evaluation of post-tonsillectomy bleeding in the adult population

A retrospective review of a consecutive series of 685 adult patients undergoing tonsillectomy was conducted. Determinations were made of the post-tonsillectomy bleeding rate, the need for intervention to control bleeding, and the blood transfusion rate. Statistical analysis was used to determine whether bleeding rates differed according to three criteria: gender, indication for tonsillectomy, and age. Post-tonsillectomy bleeding occurred in 35 patients (5.1%); five of these patients experienced bleeding during the first 24 hours postoperatively, and the remaining 30 experienced delayed bleeding. When it occurred, the mean time lapse between tonsillectomy and bleeding was 6.9 days (+/- 4.1). Twenty of the 35 patients (57.1%) required a procedure to control their bleeding, but no patient required a transfusion. There was no statistically significant difference in bleeding rates based on gender, the indication for surgery (chronic tonsillitis, obstructive sleep apnea syndrome, or to rule out neoplasia), and age. These results indicate that (1) post-tonsillectomy bleeding occurs in approximately 1 of 20 adults independent of individual patient characteristics, (2) more than half of patients who bleed are likely to require a procedure to control their hemorrhage, and (3) the need for transfusion is distinctly unlikely.     

Avoidance of primary post-tonsillectomy hemorrhage in a teaching program

OBJECTIVE: To determine the incidence of primary post-tonsillectomy hemorrhage in a teaching institution by using a uniform technique, including a 3-minute relaxation of retraction before case termination and the use of bismuth subgallate. DESIGN: Case series. SETTING: Tertiary care academic pediatric center. PATIENTS: A 7-year retrospective study was performed by using the medical records of 1286 children without a bleeding abnormality who underwent tonsillectomy (with or without adenoidectomy). A uniform technique, proposed to reduce hemorrhage, was used for 705 children and was not used for 581 children. RESULTS: No episodes of primary hemorrhage (onset < or = 24 hours after surgery) occurred, and the incidence of delayed hemorrhage (onset >24 hours after surgery) was 1.1% in the study group. The primary hemorrhage rate of the study group was significantly lower (P = .007) than the rate for the reference group (0.0% vs 1.0%), as was the total hemorrhage rate (1.1% vs 4.1%) and the delayed hemorrhage rate (1.1% vs 3.1%). CONCLUSION: A uniform technique including the use of bismuth subgallate and reassessment of the tonsillar fossae after a 3-minute observation period reduces the incidence of primary tonsillar hemorrhage in a teaching institution setting.     

A completed audit cycle on post-tonsillectomy haemorrhage rate: coblation versus standard tonsillectomy

CONCLUSION: A significant reduction in post-tonsillectomy secondary haemorrhage rate was observed after coblation tonsillectomy was abandoned in our department. OBJECTIVE: Comparison of the postoperative haemorrhage rate following coblation tonsillectomy and routine dissection tonsillectomy. PATIENTS AND METHODS: This was a retrospective study. In the first audit period, 441 sequential tonsillectomies between January and September 2002 were reviewed. Coblation was compared with cold steel and diathermy dissection with either ties and/or diathermy used for haemostasis. Coblation tonsillectomy was subsequently abandoned in our unit and, in the second audit period, all tonsillectomies (n=416) between July 2003 and August 2004 were included. Statistical analysis was performed using the chi2 test. RESULTS: The overall primary haemorrhage rate in the first audit cycle was 1.8% (8/441). In the second cycle with no coblation procedures, 1.4% of patients (6/416) suffered from primary haemorrhage (c.f. 8/441 (1.8%) in the first cycle, p=0.666). Secondary haemorrhage, was seen among 15.4% of patients (68/441) in the first audit cycle. In the second cycle, after coblation was discontinued, the secondary haemorrhage rate fell significantly (p<0.001) to 5.8% (24/416). A breakdown of the results of cold steel/diathermy and coblation techniques in both adults and children is also presented.     

Coblation tonsillectomy versus dissection tonsillectomy: postoperative hemorrhage

OBJECTIVES/HYPOTHESIS: Coblation tonsillectomy is a recently introduced surgical technique. To measure its benefits against traditional tonsillectomy techniques, it is necessary to compare their complication rates. The study aims to identify differences in reactionary and secondary hemorrhage proportions, comparing coblation with dissection tonsillectomy. STUDY DESIGN: Prospective observational cohort study. METHODS: Rates of reactionary and delayed postoperative hemorrhage were measured, comparing 844 coblation tonsillectomies with a control group of 743 tonsillectomies performed by blunt dissection with bipolar diathermy hemostasis. RESULTS: The secondary hemorrhage rate with coblation-assisted tonsillectomy was 2.25% compared with 6.19% in the control group (P <.05). The rate of secondary hemorrhage in children following coblation tonsillectomy was 0.95% compared with 4.77% in the control group (P <.05). The difference was also significant (P <.05) in the adult population (4.40% vs. 8.81%, respectively). No difference was found in the reactionary hemorrhage proportions. CONCLUSION: In the study, coblation tonsillectomy was associated with a lesser incidence of delayed hemorrhage, more significantly in the pediatric population. The new technique using tissue coblation for tonsil dissection offers significant advantages in the postoperative period compared with dissection tonsillectomy with bipolar diathermy hemostasis. Coblation is associated with less postoperative pain and early return to daily activities. Also, there are fewer secondary infections of the tonsil bed and significantly lower rates of secondary hemorrhage with coblation. These results and the disposable nature of the coblation equipment promote coblation tonsillectomy as the authors' preferred dissection method.     

Post-tonsillectomy hemorrhage: results of a 3-month follow-up

Episodes of post-tonsillectomy hemorrhage are unpredictable and potentially life-threatening. Primary post-tonsillectomy hemorrhage (< 24 hr postoperatively) is generally considered to be more common and more serious than secondary hemorrhage (> 24 hr). Therefore, recent studies have focused on the control of primary hemorrhage in order to determine the appropriate length of postoperative observation. The issue of follow-up is becoming more important in light of the increasing popularity of outpatient tonsillectomy. We undertook a prospective study to evaluate the incidence of post-tonsillectomy hemorrhage over the short and long term (3 mo). We studied 602 patients, aged 23 months to 89 years (mean: 20.6 yr), who had undergone inpatient tonsillectomy in 1999 and who had been hospitalized for at least 5 days. Our goal was to ascertain the number of episodes of postoperative hemorrhage that required surgical treatment under general anesthesia. We were able to contact 601 of these patients (or their parents) by telephone 3 months postoperatively to inquire about any instances of delayed secondary bleeding. In all, 16 patients (2.7%) had experienced post-tonsillectomy bleeding that required surgically achieved hemostasis under general anesthesia. Of this group, 11 patients (68.8%) had experienced primary hemorrhage and were treated immediately, and five (31.3%) experienced secondary hemorrhage. One patient in the latter group experienced excessive bleeding 38 days postoperatively, which we believe is the latest episode of secondary bleeding reported to date. Based on the findings of this study, we believe that a postoperative follow-up period of 10 days is sufficient to identify all but the most rare cases of post-tonsillectomy hemorrhage.     

Lethal outcome of post-tonsillectomy hemorrhage

Despite the large number of tonsillectomies performed little knowledge exists about post-tonsillectomy hemorrhage (PTH) with lethal outcome. This study was performed to evaluate clinical features in a larger patient population with emphasis on the onset of this complication. A nationwide collection of cases was performed based on personal communication, expert reports to lawsuits and professional boards, and case reports received after a plea published in a professional national journal. Clinical data of 29 patients were collected of whom the 18 were children (64%). With one exception all patients experienced secondary PTH (>24 h) occurring 1–28 days after tonsillectomy. Aspiration contributed to lethal outcome in 13 cases. Fatalities were unavoidable although 21 patients were in the hospital. Massive vomiting of blood was observed in 11 patients. There were 11 patients without (group A) and 18 with (group B) episodes of repeated bleeding. This study suggests that particularly children are endangered by lethal PTH. Inpatient treatment was unable to prevent lethal outcome in this selected patient population. However, it appears wise to re-admit patients with delayed PTH, since excessive PTH may occur. These unexpected and unpredictable situations require an immediate and adequate medical treatment by a skilled staff. The paucity of data currently does not allow calculation of a cut-off point at which the risk of life-threatening PTH significantly decreases. Secondary PTH remains a substantial complication.     

Nachblutungsrate nach Coblation-Tonsillektomie

Background

With over 100,000 cases annually, tonsillectomy is one of the most frequently performed ENT surgical procedures in Germany. Hemorrhage ranks among its serious postoperative complications. In this systematic review, we analyze hemorrhage following tonsillectomies performed using coblation technique.

Methods

Of the 135 studies identified, 38 could be included in the analysis, most being prospective randomized controlled studies. Data from 6290 patients were gathered.

Results

Of all tonsillectomies performed, hemorrhages occurred in 355 patients. Of these, 256 cases could be classified as 41 primary and 215 secondary hemorrhages. Overall, the total hemorrhage rate for the coblation procedure was 4.9% (95%-CI: 0.044–0.054) for the fixed effects model.

Conclusion

Significantly higher rates of postoperative hemorrhage were found in a few studies, yet they were well above the 95% confidence interval of 4.4–5.4% of the literature. These studies could possibly be interpreted in terms of an autodidactic learning process. As with any surgical technique, proper training is essential.