Robotic distal pancreatectomy - the first experience.

INTRODUCTION: Minimally invasive distal pancreatectomy (MIDP) includes both laparoscopic and robotic distal pancreatectomy (RDP). MIDP is often adopted first due to the absence of the requirement of a complex reconstruction. In recent years, an increase in the use of robotic surgery has been noted. METHODS: The authors present initial experience with RDP and retrospective analysis of data from prospectively collected database. RESULTS: Between September 2021 and October 2022 five patients undergoing RDP with splenectomy performed in the 3rd Department of Surgery, 1st Faculty of Medicine, Charles University and Motol University Hospital were included from a prospectively maintained database. The age was from 20 to 70 years. No conversion was required. One patient underwent reoperation due to staple-line hemorrhage. Postoperative hospital stay was from 4 to 14 days. The follow-up period was from 2 to 14 months. CONCLUSION: Our first experience demonstrates RDP is a safe and efficacious approach for tumors of pancreatic body and tail in selected patients. A larger number of patients is needed to obtain more accurate results.

Robotic-assisted minimally invasive esophagectomy - our first experience.

INTRODUCTION: Minimally invasive esophagectomy is associated with lower postoperative morbidity and better quality of life compared to open esophagectomy in patients with comparable oncological outcomes. Robotic-assisted surgery represents the next step in the development of mini- mally invasive surgery. We aim to present the results of a pilot cohort of patients undergoing robotic-assisted minimally invasive esophagectomy (RAMIE). METHODS: An initial cohort of patients with RAMIE was retrospectively analyzed. Operative characteristics, histopathological results, postoperative course, incidence of complications, and postoperative mortality were evaluated. RESULTS: From 3/2022 to 6/2023, a total of 31 patients underwent RAMIE at our institution, including hybrid RAMIE (robotic abdomen, open chest) in 11 and total RAMIE in 20 patients. Most patients were male, had locally advanced tumors, predominantly adenocarcinoma and neoadjuvant treat- ment. Thirty patients had Ivor-Lewis and one patient had McKeown esophagectomy. The median total operative time was 495 minutes and median blood loss was 200 mL. R0 resection was achieved in 87% of patients. A median of 26 lymph nodes were removed. Postoperative Clavien-Dindo ≥3 complications occurred in 9 (29%) patients. Four (13%) patients required reoperation. Anastomotic leak was found in 5 (16%) and pneumonia in 9 (29%) patients. The median hospital stay was 9 days. One patient died in the postoperative period. Thirty-day and 90-day mortality rates were 0% and 3.2%, respectively. CONCLUSION: Our initial experience shows that RAMIE is a safe surgical procedure and we consider its implementation at our institution to be success- ful. After overcoming the learning curve, we hope to reduce the operative time and increase the medical benefit for the patient.

The value of 18F-FDG-PET testing in the management of esophageal and gastroesophageal junction adenocarcinoma - review.

BACKGROUND: Preoperative chemoradiotherapy (CRT) and perioperative chemotherapy (CHMT) are a standard of care for distal esophageal and gastroesophageal junction adenocarcinomas. PET/CT using 18F-fluorodeoxyglucose (18F-FDG-PET/CT) is one of the basic staging examinations with a certain prognostic significance and has recently been studied for the possibility of showing prognostic or predictive results suitable for the individualization of treatment strategy. PURPOSE: The aim of this review is to map the role of 18-FDG-PET/CT in predicting the response to CHMT and CRT, which could be a starting point for personalized treatment. CONTENT: The change in metabolic activity in the maximum standardized uptake value is most often used to quantify the treatment response; total lesion glycolysis is a volumetric parameter. A method for standardizing measurements was offered in the PERCIST system. Several studies have been published showing that the decrease in metabolic activity after chemotherapy correlates with a surrogate measure of the treatment outcome, which is the degree of tumor regression in the resected tissue, but also with survival or time to progression. The cut-off value separating sensitive and resistant tumors varied from 33 to 78%, the measurement took place either at the end of neoadjuvant treatment or „early“, about 2 weeks after the first cycle of CHMT. However, this value has not yet been validated and the parameters of sensitivity, specificity and negative and positive predictive values for the prediction of treatment outcome fluctuated significantly. In the case of preoperative CRT, PET/CT could not predict the complete response to the treatment with satisfactory accuracy. Studies using early metabolic response to change the treatment strategies in non-responders have not yet shown whether changing the treatment in patients without an early metabolic response to CHMT will improve survival. In the case of randomization, a standard arm with a continuation of the original CHMT was never used. CONCLUSION: Evaluation of an early PET-based response has the potential to modify the treatment in patients who have not demonstrated an early response to CHMT. However, this is not an approach suitable for routine practice outside of clinical trials. So far, it seems possible to use an early metabolic response for small, exploratory studies evaluating new agents and their combinations in the preoperative treatment of localized esophageal cancer or gastroesophageal junction cancer.

Treatment of anastomotic leak after Ivor Lewis esophagectomy.

INTRODUCTION: Anastomotic leak (AL) is one of the most serious surgical complications after esophagectomy. Endoscopic, radiological and surgical methods are used in the treatment of AL. The aim of this study was to retrospectively evaluate our therapeutic procedures and results of AL treatment after Ivor Lewis esophagectomy (ILE). METHODS: Retrospective audit of all ILEs performed in the years 20052019. Evaluation of AL treatment results according to Esophagectomy Complication Consensus Group (ECCG) classification and according to the primary therapeutic procedure with a focus on the treatment with esophageal stent. RESULTS: Out of 817 patients with ILE, AL was detected in 80 patients (9.8%): ECCG type I 33 (41%), type II 23 (29%) and type III 24 (30%) patients. Some 33 patients (41%) were treated conservatively. Esophageal stents were used in 39 patients (49%), of which 18 (23%) had concomitant percutaneous drainage and 17 (21%) were reoperated. Reoperation without a stent insertion was performed in 7 patients (9%). Esophageal diversion with cervical esophagostomy was performed in a total of 16 patients (20%). Esophageal stent treatment was successful in 24/39 patients (62%). Airway fistula occurred in 4 patients treated with stent (10%). Endoscopic vacuum therapy was successfully used in three patients after stent failure. Eight patients (10%) died as a result of AL. Mortality of AL type I, II and III was 0%, 4% and 29%. CONCLUSION: Successful treatment of AL requires an individual and multidisciplinary approach. The primary effort should aim to preserve anastomosis using endoscopic and radiological methods. In case of insufficient clinical effect, we recommend not to hesitate with reoperation. If primary therapy fails, the life-saving procedure is a cervical esophagostomy.

[18 F]Fluorodeoxyglucose PET/CT and prediction of histopathological response to neoadjuvant chemotherapy for adenocarcinoma of the oesophagus and oesophagogastric junction.

BACKGROUND: The aim of this prospective study was to assess whether [18 F]fluorodeoxyglucose PET can be used to predict histopathological response early in the course of neoadjuvant chemotherapy in patients with adenocarcinoma of the oesophagus and oesophagogastric junction. METHODS: Following the PET response criteria in solid tumours (PERCIST 1.0) as a standardized method for semiquantitative assessment of metabolic response, FDG-PET/CT was performed before (PET1) and after (PET2) initiation of the first cycle of chemotherapy. The relative changes in the peak standardized uptake value (ΔSUL) and total lesion glycolysis (ΔTLG) between PET1 and PET2 were correlated with histopathological response, defined as less than 50 per cent viable tumour cells in the resection specimen. A receiver operating characteristic (ROC) curve analysis was used to identify the optimal cut-off value with the highest accuracy of histopathological response prediction. RESULTS: PET2 was performed a median of 16 (range 12-22) days after the start of chemotherapy. Some 27 of 90 patients who underwent surgery had a histopathological response. There was no association between the median ΔSUL or median ΔTLG and the histopathological response. A post hoc analysis in 47 patients with PET2 performed 16 days or less after the start of chemotherapy showed that ΔTLG, but not ΔSUL, was associated with the histopathological response (P = 0·009). The optimal cut-off value of ΔTLG was 66 per cent or more. CONCLUSION: FDG-PET/CT after the first cycle of chemotherapy does not predict histopathological response in patients with adenocarcinoma of the oesophagus and oesophagogastric junction.

Long-term outcomes and prognostic factors of patients with pulmonary carcinoid tumors.

The aim of the study was to evaluate type of surgery, long-term survival and factors influencing outcome of pulmonary carcinoid tumors. We reviewed our database of 137 patients surgically treated for typical or atypical carcinoid tumors at our department between 1998 and 2013. There were 95 (69%) patients with typical carcinoid (87 N0, 6 N1, 2 N2) and 42 (31%) with atypical carcinoid (26 N0, 8 N1, 8 N2). Patients with atypical carcinoid were older than those with typical carcinoid (median age of 57±8.1 and 50.5±15.8 years, respectively, p<0.00001). The resection performed consisted of 6 (4.4%) pneumonectomies, 110 (80.1%) lobectomies and bilobectomies, 15 (11%) sleeve lobectomies, 2 (1.5%) resections of main bronchus and 4 (3%) wedge resections. Overall 5- and 10-year survival rates for different tumors were as follows: typical carcinoid: 97.2% and 89.9%, respectively; atypical carcinoid 71.1% and 62.2%, respectively. Statistical analyses indicated that histology (typical carcinoid, p<0.00001), age (less than 45 years, p=0.004) and nodal status (N0, p=0.0002) were significant prognostic factors for better prognosis. Histological sub-type and nodal involvement appear as the most important factors influencing the prognosis. Systemic lymphadenectomy is recommended and should always be performed.

[Intramural haematoma of the oesophagus - a case report and literature review]. / Intramurální hematom jícnu - kazuistika a prehled literatury.

Intramural hematoma of the oesophagus is a rare diagnosis presenting with retrosternal pain, dysphagia and haematemesis. It is caused by barotrauma or direct injury to the esophagus, or it may occur spontaneously without apparent cause, which is more common in patients taking antiplatelet or anticoagulant medications. In most cases, treatment is conservative. Rarely, endoscopic, endovascular or surgical treatment is effective. This article presents a case report of a female patient with spontaneous haematoma of the oesophagus solved conservatively and discusses further possibilities of the course and treatment of the disease.Key words: intramural haematoma of the oesophagus IHE.

Pneumonectomy for non-small cell lung cancer: predictors of early mortality and morbidity.

BACKGROUND: The aim of this study was to determine independent risk factors affecting postoperative morbidity and mortality after pneumonectomy for non-small cell lung cancer (NSCLC). METHODS: A review of 329 patients having pneumonectomy for NSCLC between January 1, 1998 and July 31,2012 was undertaken. Factors affecting morbidity and mortality were analyzed by univariate and multivariate analyses. RESULTS: The overall 30-day mortality rate was 5.1%. Smoking habits, chronic obstructive pulmonary disease (COPD) status, neoadjuvant therapy and obesity had no statistical influence on the short-term outcome. Coronary artery disease and respiratory failure were identified as risk factors for increased 30-day mortality (p < 0.01). Right pneumonectomy and presence of respiratory failure with mechanical ventilation increased the incidence of bronchopleural fistula (p < 0.01). CONCLUSIONS: Pneumonectomy for NSCLC carries an acceptable operative morbidity and mortality. Coronary artery disease, right pneumonectomy and respiratory failure adversely affect morbidity and mortality after this procedure.

Peri-operative chemotherapy in patients with oesophageal and gastro-oesophageal junction cancer - three years of experience.

Peri-operative chemotherapy has been found to benefit patients with oesophageal and gastro-oesophageal junction adenocarcinoma. This study's aim was to evaluate the efficacy and tolerance of this treatment. The study included patients with carcinoma of the lower oesophagus and gastro-oesophageal junction in whom the disease was evaluated as potentially operable. Chemotherapy (CHT) consisted of three preoperative and three postoperative cycles of intravenous epirubicin and cisplatin on day 1 plus a continuous infusion of fluorouracil for 21 days (ECF) or oral capecitabine for 14 days (ECCap). Postoperative radio-chemotherapy (CRT) with fluorouracil or capecitabine after CHT was indicated in patients with two and more positive lymph nodes. Sixty-three patients started the treatment. Median follow-up was 32 months. Preoperative CHT was completed by 62 patients, 52 had surgery, 46 had radical resection, 25 patients had pN0 and 21 patient pN plus findings. Postoperative CHT was started in 39 (62%) patients and completed in 32 (51%). Ten (16%) patients had postoperative CRT. Adverse events of grade 3 and 4 were: neutropenia 17%, vomiting 8%, fatigue 5%, diarrhoea 3%. Reasons for omitting surgery in 11 (17%) patients were: progression in 7 patients, medically unfit in 3 patients, other in 1 patient. In the reporting period there were recurrences in 39 of all patients, in 7 locoregional only, in 10 distant plus locoregional, and in 19 distant metastases. Median survival was 24.1 months and 3-year survival rate was 42%. Peri-operative chemotherapy ECF/ECCap was feasible and well tolerated. Radical resection was performed in most patients.

Early diagnostic markers of sepsis after oesophagectomy (including thromboelastography).

BACKGROUND: Early diagnosis of sepsis and its differentiation from the noninfective SIRS is very important in order that treatment can be initiated in a timely and appropriate way. In this study we investigated standard haematological and biochemical parameters and thromboelastography (TEG) in patients who had undergone surgical resection of the oesophagus to find out if changes in any of these parameters could help in early differentiation between SIRS and sepsis development. METHODS: We enrolled 43 patients (aged 41-74 years) of whom 38 were evaluable. Blood samples were obtained on the morning of surgery and then at 24-hour intervals for the next 6 days. Samples were analysed for procalcitonin (PCT), C-reactive protein (CRP), interleukin-6 (IL- 6), aspartate transaminase (AST), alanine transaminase (ALT) , lactate, white blood count (WBC), D-dimers, antithrombin (AT), international normalised ratio (INR), activated partial thromboplastin time (APTT) and parameters of TEG. RESULTS: Significant differences between patients who developed sepsis during this period (9 patients) and SIRS were found in ALT on Day 1, in AST on Days 1-4, in PCT on Days 2-6; in CRP on Days 3-6; in IL-6 on Days 2-5; in leucocytes on Days 2, 3 and 6; and in D-dimers on Days 2 and 4. Significance values ranged from p < 0.0001 to p < 0.05. CONCLUSIONS: Sequential measurements of ALT, AST, PCT and IL-6 during the early postoperative period can be used for early differentiation of sepsis and postoperative SIRS after oesophagectomy. Among the coagulation parameters measured, only D-dimer concentrations appeared to be helpful in this process. TEG does not seem to be a useful early predictor of sepsis development; however it can be used to differentiate sepsis and SIRS from Day 5 after surgery.

[Timeline trends in surgery of bronchogenic carcinoma]. / Casové trendy chirurgické terapie bronchogenního karcinomu.

BACKGROUND: The aim of our study was to determine how patient preoperative status and outcomes of resection have changed over last 12 years. MATERIAL AND METHODS: This retrospective study of prospective database included 1412 patients operated from January 1,1998 through December 31,2009. Patient characteristics and outcomes were compared for two time periods (1998-2003 and 2004-2009). RESULTS: We performed 985 lobectomies with 30-days mortality 1.8% and 300 pneumonectomies with 30-days mortality 5.7%. Median of survival of all 1412 patients was 4.3 year and 5-year survival was 45%. The percentage of female patients, lobectomies and adenocarcinoma increased over time, as well as age of our patients. Outcome improved over time, with significant decrease in 30-days mortality after pneumonectomy (8.2% vs. 2.3%, p = 0.029). The overall 3-year survival improved in patients with III. stage (30 % vs. 40%, p = 0.012). CONCLUSION: Our study identified time trends which are in-line with increased incidence of lung cancer among women and with improvement of preoperative evaluation, preoperative and postoperative care

Risk factor analysis for early mortality and morbidity following pneumonectomy for non-small cell lung cancer.

OBJECTIVES: The purpose of this report is to analyze factors affecting morbidity and mortality following pneumonectomy for non-small cell lung cancer (NSCLC). METHODS: We reviewed our institutional experience with all consecutive patients undergoing pneumonectomy for NSCLC from 1998 to 2010. Patients were analyzed with regard to hospital mortality and morbidity and long-term outcome. RESULTS: There were 310 patients following pneumonectomy. Overall 30-day mortality rate was 5.5 %. Chronic obstructive pulmonary disease, induction therapy, smoking habits and obesity had no statistical influence on short-term outcome. Coronary artery disease and respiratory failure were identified as risk factors for increased 30-day mortality (p<0.01). Right pneumonectomy and presence of respiratory failure with mechanical ventilation increases the incidence of bronchopleural fistula (p<0.01). CONCLUSIONS: Patients with right pneumonectomies are at increased risk. Coronary artery disease and respiratory failure adversely affect morbidity and mortality after this procedure (Tab. 3, Ref. 19). Full Text in free PDF www.bmj.sk.

Time trend in the surgical therapy of lung cancer.

BACKGROUND: The purpose of our study was to clarify results of surgery for non-small cell lung cancer (NSCLC) and its time trends. METHODS: We retrospectively reviewed our prospective database of patients who underwent surgery for NSCLC between 1998 and 2009 in our institution. Patients were divided into two equal 6-year periods according to the year of surgery (1998-2003 and 2004-2009). RESULTS: One thousand, four hundred and twelve patients underwent operation for NSCLC. We performed 985 lobectomies with 30-days mortality of 1.8 % and 300 pneumonectomies with 30-days mortality of 5.7 %. Median of survival of all 1412 patients was 4.3 year and 5-year survival was 45 %. The percentage of female patients, lobectomies and adenocarcinomas increased over time, as well as the age of our patients. Outcome improved over time, with significant decrease in a 30-days mortality after pneumonectomy (8.2 % vs 2.3 %, p=0.029). The overall 3-year survival improved in patients with stage III (30 % vs 40 %, p=0.012). CONCLUSION: Outcomes of lung resection for NSCLC improved over time despite a worsening of some elements of preoperative status. The shift in histological distribution was associated with an increasing proportion of patients with stage I, a lower operative mortality and better 3- and 5-year survival. These trends are due to improvement of preoperative evaluation, preoperative and postoperative care (Tab. 1, Fig. 2, Ref. 9). Full Text in free PDF www.bmj.sk.

[Esophageal perforation]. / Perforace jícnu.

OBJECTIVE: Evaluation of patients with acute esophageal perforations with single institution experience. MATERIAL AND METHODS: The authors evaluate the set of 64 consecutive patients with esophageal perforation treated in our department between January 2000 and December 2010. In all patients were before decision making performed CT scans and X-ray examination with contrast agent administration. For selected patients was also accompanied upper endoscopy. Excluded were patients with malignant tracheoesophageal fistula and patients with perforation of malignant stenosis treated with palliative intent. RESULTS: The mean age was 62 years (range 24-90), of which one third (34.4%) were aged 70 years or more. We received the iatrogenic perforation in 45 (70%) patients, less than one quarter (n = 15; 23%) consisted of spontaneous perforation, in three patients we have failed to determine the cause of perforation (5%) and one patient experienced perforation during removal of foreign body. Perforation of the thoracic esophagus in 41 patients, in 20 (31%) cases in the upper and middle third and 21 (33%) in the distal third of the thoracic esophagus. Cervical perforation was noted in 14 patients (22%) and abdominal of the 9 patients (14%). 92% of patients were treated surgically (n = 59). 43% (n = 27) were treated by primary suture of the perforation, esophageal resection with primary reconstruction was performed in 4 patients, esophagectomy with terminal esophagostomy and nutritional jejunostomy in 7 patients, 4 patients were treated by surgical drainage and only 7 patients, we introduced endless lavage. In 9 cases we have resected affected portion of esophagus with stapler closure in the chest. Conservative management of esophageal perforation we proceeded in 5 patients in whom a stent was introduced and the perforation successfully healed. Overall mortality in our set of patients is 23.4%. CONCLUSION: Conservative procedure in carefully selected patients could be an alternative to radical and inherently surgical procedures. Published results and our little experience are encouraging, but this topic is still under study.

[Impact of neoadjuvant chemotherapy on postoperative complications following pneumonectomy]. / Vliv neoadjuvantní terapie na pooperacní komplikace po pneumonektomii.

BACKGROUND: The risks of complications in patients undergoing pneumonectomy after preoperative chemotherapy for nonsmall cell lung cancer remain controversial. We reviewed a consecutive series of patients having undergone pneumonectomy in a single centre. MATERIAL AND METHODS: This retrospective study included 292 patients operated from January 1, 1998 through December 31, 2008. Group 1 included patients those who received preoperative chemotherapy and pneumonectmy (57 patients, 19%), and group 2 included patients who underwent pneumonectomy alone (235 patients, 81%). The main objectives were 30-day and 90-day mortality rates, and major postoperative complications. RESULTS: There was no statistically significant difference in patients' age, gender, cardiovascular co morbidity, histology and side of pneumonectomy between these two groups. Overall 30-days and 90-days mortality rates were 5.5 % and 8.6%, respectively. Postoperative mortality at 30 days was 5.2% in group 1 and 5.6 % in group 2 (p = 0.16), and 10.5% for group 1 and 8.1% in group 2 at 90 days (p = 0.8). Incidence of empyema was 5.2% in group 1 and 3.0% in group 2 (p = 0.12); incidence of bronchopleural fistula was 3.5 % in group 1 and 3.0% in group 2 (p = 0.10); incidence of postoperative respiratory failure was 3.4% in group 1 and 3.0% in group 2 (p = 0.75). CONCLUSION: Preoperative chemotherapy does not significantly increase postoperative morbidity and early mortality after pneumonectomy in our experience.

Predisposing factors of atelectasis following pulmonary lobectomy.

BACKGROUND: The aims of our study were to investigate postoperative atelectasis complicating pulmonary lobectomy, identify risk factors and evaluate its relationship to other postoperative complications. MATERIAL AND METHODS: From January 2004 to April 2007, 412 patients underwent pulmonary lobectomy. We performed a retrospective analysis of our prospective database. Post-lobectomy atelectasis (PLA) was defined as an ipsilateral opacification of the remaining lobe with an ipsilateral shift of the mediastinum on the chest radiography, requiring bronchoscopy. RESULTS: The incidence of PLA was 6.6%, comprising 29% of all postoperative pulmonary complications seen. There was no statistically significant difference in patient age, gender, ASA score, cardiovascular co-morbidity or operation time for the PLA group versus the group without this complication. Current smokers were at a higher risk for PLA, but this incidence did not reach statistical significance. Chronic obstructive pulmonary disease (COPD) was the only preoperative variable increasing the risk of PLA (p < 0.05). Patients undergoing a right upper lobectomy, either on its own or in combination with a right middle lobe resection, had a significantly higher incidence of PLA when compared with all other types of resection (p < 0.05). CONCLUSIONS: Patients with COPD and those undergoing right upper lobe resection have an increased risk of PLA. In this group of patients we should use pre-operative (cessation of cigarette smoking, treatment of airflow obstruction in patients with COPD), intra-operative (duration of operation) and postoperative (intensive physiotherapy and effective postoperative pain control) measures to decrease the risk of PLA. Although often solitary, PLA is associated with a longer hospital stay.

[Stents--palliative and curative management of esophageal conditions. Seven-year surgical experience]. / Stenty--paliativní a kurativní osetrení jícnu. Sedmileté zkusenosti chirurgického pracoviste.

The authors present their experience with endoscopic introduction of stents into esophagus and cardia based on data collected from a group of 520 patients. Their study included both paliative management of stenoses in carcinomas of the esophagus and cardia, as well as management of other esophageal conditions, including fistules, perforations and various types of stenoses, including the use of novel absorbable stents.

[Our experience with diverticulectomy in symptomatic Zenker's diverticulum]. / Unsere Erfahrungen mit der Zenkerdivertikelresektion.

INTRODUCTION: The frequency of endoscopic procedures for management of Zenker's diverticulum has increased rapidly in the last years. Endoscopic methods are highly effective. We tried to answer the question whether the development of endoscopic methods means the end of open surgery. PATIENTS AND METHODS: In this retrospective study 30 patients (11 men, 19 women) with an average age of 70.9 (49-88) years with Zenker's diverticulum (ZD) were included. All patients were treated with an open transcervical approach between October 2000 and July 2005. In all cases the region of ablation of the diverticulum was closed with a primary handmade suture. In two cases an additional myotomy was performed. For evaluation of the long-term results the patients were sent a questionnaire. To objectify the findings, all patients underwent postoperatively an X-ray examination of the esophagus. The literature was searched by PubMed. RESULTS: 30 patients underwent 32 operations. 91 % of the inquired patients evaluated the operation as successful. An anastomotic leakage was observed in 3 patients, a lesion of the recurrent laryngeal nerve occurred in 2 patients. CONCLUSION: Despite the rapid development of endoscopic methods the open surgical approach remains a reliable and minimal invasive solution of ZD with excellent results and low complication rate. In patients that cannot undergo endoscopic procedures the surgical approach represents the only therapeutic option. Therefore surgical training for repairing ZD is also necessary for the future.