利用3D打印腹腔镜尼森胃底折叠术模型缩短住院医师的学习曲线

摘要

本研究描述了3D打印模型如何有效加快住院医师在外科培训期间掌握尼森胃底折叠术中所用高级腹腔镜手术技能的速度，从而增强未来的临床准备能力。

摘要

腹腔镜Nissen胃底折叠术（LNF）需要经过大量训练才能达到手术熟练水平，且在早期学习曲线阶段存在显著的并发症风险。本文介绍并设计了一种利用3D打印解剖模型的结构化培训方案，旨在加速高级腹腔镜技能的掌握。该方案包括模型的制作与组装，并将其整合到针对LNF特定培训课程中，重点训练涉及高级缝合技术的关键操作环节。模型包含解剖结构准确的标志点，全部采用专用硅胶材料制造。本文提出了一套分步培训课程，专注于掌握LNF中最困难的操作部分，包括裂孔关闭、补片缝合以及胃底折叠包裹。来自一名试点参与者的代表性结果显示可量化的学习曲线：在六次训练 session 中，总操作评分从21分提高至42分，操作时间从95分钟缩短至34分钟，逐步接近专家基准水平。该培训范式的整体有效性已在一项对比研究中得到验证：与对照组相比，使用3D打印模型训练的组别在手术室中的客观结构化技术技能评估（OSATS）得分显著更高（26.25 ± 1.67 vs. 17.50 ± 2.07），手术持续时间更短（76.25 ± 2.49 vs. 110.13 ± 3.36 min），证实了该方案对临床技能的积极影响。这一经过验证的培训方案为实施有效的LNF培训项目提供了一种可重复的方法，能够测量并促进技能的渐进式发展。

引言

腹腔镜Nissen胃底折叠术（LNF）已成为胃食管反流病（GERD）的金标准外科治疗手段¹，正逐渐取代终身药物抗反流治疗。LNF 技术复杂，需要较长的学习曲线，通常需完成至少 20 例手术才能达到手术熟练水平²显著影响患者预后³ 并发症发生率在术者初期手术中为24%至55%^4,5,6，尤其是在前五次操作中。后续证据表明，在第15至25次操作期间，并发症发生率下降至约10%^4,6在最初的20例手术中，最常见的并发症主要与技术操作能力不足有关，具体包括食管后间隙的分离困难、短胃血管的离断、胃底游离不充分、膈肌裂孔的缝合闭合困难，以及胃底折叠缝合的技术挑战。^7,8掌握这些步骤与将并发症发生率降低2%–10%相关^3,8,9.

目前，外科教育提供了多种模拟训练平台，以帮助受训者快速克服学习曲线¹⁰。然而，针对高级腹腔镜手术的标准化培训课程尚未建立^11,12,13,14。研究表明，住院医师培训项目结束后，许多住院医师仍缺乏独立开展高级腹腔镜手术的信心，往往需要进一步接受专科培训以获得足够的技术熟练度¹⁵。尤为重要的是，尽管腹腔镜手术基本技能（Fundamentals of Laparoscopic Surgery, FLS）已在住院医师培训项目中实施，但研究发现，住院医师在基于模拟的体内缝合技能与其在手术室（OR）中的实际表现之间存在显著差异，提示有必要建立一个介于FLS与手术室缝合之间的过渡性培训平台，以弥合这一差距¹⁶。此外，在达到FLS熟练水平之后，住院医师在毕业前仍迫切需要进一步提升其在高级腹腔镜手术方面的技能与信心，超越FLS所涵盖的范围。

为解决这一问题，技术进步已提供了潜在的培训解决方案。虚拟现实（Virtual Reality, VR）等干性模拟实验室可提供详细的解剖结构呈现，并具备LNF所特有的刻意练习机会¹⁷。然而，建立和维护VR模拟实验室的成本是一个重大挑战¹⁸。传统的湿性模拟实验室包括尸体和活体动物模型，尽管在许多手术操作中可作为理想的指导工具，但在解剖保真度、伦理及健康安全规范方面存在局限性¹⁹，尤其在后新冠疫情背景下，还面临成本、后勤及排程安排等方面的挑战^10,20。

为了提供一种替代方案，我们基于实际CT建模重建数据，结合三维（3D）打印技术和硅胶材料制作，开发了一种用于腹腔镜近端胃切除术（LNF）培训的上腹部解剖模型。该模型具有高度可重复使用性，在多次练习后，腹膜层和胃短血管等关键组件可更换，单次训练通常可支持多达8次操作尝试。已有针对类似自制模型的验证研究表明，此类模型在手术技能获取方面具有显著效果，相关结果已由Wang等²¹和A.ghazi等²²报道。

该3D打印模型可与操作视频及分步演示视频结合使用，有望减轻临床环境中早期学习曲线带来的挑战。本研究旨在证明该培训模式在喉神经外科（LNF）技能获取中的有效性和实施效果。

方案

本研究经浙江省人民医院机构审查委员会批准，并依照既定的伦理准则进行。所有人类受试者均签署了书面知情同意书。所用试剂与设备列于材料表中。

1. 准备3D打印的LNF模型

注意：使用硅胶制作单个3D打印解剖模型的过程已在先前的报告中详细讨论过²¹。

1. 使用层厚为 0.5 mm 的三维计算机断层扫描进行扫描。
2. 获取特定器官的医学数字成像和通信（DICOM）数据。
3. 将 DICOM 数据转换为 STL 格式。将文件导入 Magics 24 软件（文件 > 导入）。根据需要通过运行自动修复（路径：菜单栏 > 修复 > 自动修复）、执行部分手动修复（路径：菜单栏 > 修复 > 手动修复）以及去除噪声壳体和碎片（路径：菜单栏 > 修复 > 去除噪声壳体）来修复模型。
4. 修复完成后，添加支撑结构（路径：菜单栏 > 定向 > 创建支撑）。最后导出已修复并添加支撑的模型，根据需要执行切片层导出（路径：菜单栏 > 文件 > 导出 > STL）。
5. 使用光固化（SLA）3D 打印机打印器官（肝脏）模具。采用以下操作参数以实现精确模具制造：刮刀起始高度：4.5 mm，刮刀速度：60 mm/s，Z 轴速度：2 mm/s，温度控制：30 °C，固化速度：0.2 mm/s，光斑尺寸：0.07 mm，层厚：0.1 mm。
6. 使用超声波清洗机以乙醇溶剂在 40 kHz 条件下彻底清洗打印的模具，持续 3–5 分钟。
7. 在紫外光（UV）固化箱中完成模具的二次固化。确保在波长为 405 nm、强度为 30 mW/cm² 的紫外光下照射 30 分钟，以实现完全固化。
8. 配制双组分零度硅胶（国原 Mix，将 A 组分 750 g 与 B 组分 750 g 混合）。将混合物置于 22–25 °C 的环境温度下，避免高温影响操作时间。
9. 将混合物放入真空箱中以去除气泡。设定真空度为 -0.09 MPa，脱泡时间为 8 分钟。
10. 将真空脱泡后的硅胶从真空箱中倒入器官（肝脏）模具中。观察确保硅胶均匀填充模具，且表面无明显大气泡。
11. 静置使其完全固化。该过程应在密闭环境中于 25 °C ± 2 °C 下进行 1 小时，以确保成型质量。
12. 完全固化后，在模具组件的内表面涂抹一层薄薄的凡士林作为脱模剂，并小心拆模，获得最终的硅胶器官（肝脏）模型。
13. 检查模型表面是否完整，解剖结构是否清晰。若表面出现塌陷或存在明显气泡，则应重新制模。
    注意：此步骤对每个器官重复执行，最终组装成 LNF 模型（图 1）。

2. 构建LNF模型

1. 根据相应的解剖布局放置 3D 打印的器官模型。
2. 将连接胃的食管穿过膈脚之间的开口和胃底进入纵隔区域。
3. 将大网膜、肝脏和胆管放置在胃的邻近位置，并用针固定以支撑。这些结构在淋巴结清扫术（LNF）培训的视觉和触觉训练中均具有重要意义。
4. 将皮肤放置在塑料平台上，使用魔术贴和针固定。将平台内部的光源连接至电源，以改善照明条件。
5. 在皮肤上制作三个切口，以实现符合人体工学的穿刺套管定位。通过在中央插入一个 5 mm 穿刺套管用于 30 度腹腔镜，并在两侧各插入一个 10 mm 穿刺套管用于腹腔镜持针器、无损伤抓钳和腹腔镜剪刀，建立视野三角。
6. 使用夹具固定腹腔镜，并将其连接到电视或笔记本电脑的高清显示屏幕的 USB 接口。
7. 使用 CT-1 针在模型内放置一根 2-0 丝线缝线。

3. 培训课程

注意：该手术步骤分为五个组成部分，每个步骤的重要性均由先前的临床前研究预先确定^21,23。对于大型食管裂孔疝修补术而言，膈肌脚关闭和补片缝合是基础步骤，同时也受到模型自身局限性的制约。

1. 沿食管周围切开硅胶凝胶层，建立食管后方隧道。确保视野清晰，完整游离食管周径至少4-5 cm，并注意膈肌的右脚和左脚结构。
2. 识别双侧膈肌脚，并使用三个间断缝线进行缝合。确认膈肌脚在无张力的情况下牢固闭合，确保膈肌柱充分对合。
3. 正确放置补片，并将其两侧对称地缝合固定于膈肌上。确认补片位置均匀、固定牢靠，平展无皱褶，并与食管壁保持清晰的边缘距离。
4. 正确执行“鞋擦动作”（shoe shine manoeuvre），将胃底向上折叠，包裹食管下段2-3 cm。确保形成一个松软、无张力、360度的胃底折叠，长度不超过2 cm。
5. 使用三个间断缝线在1.5 cm长度范围内妥善闭合折叠部分。确认缝线位置牢固且一致，以维持胃底折叠的完整性，并通过探条检查确保折叠不过紧。
   注：在训练开始前，专家在3D模型上进行腹腔镜Nissen胃底折叠术（LNF）的分步操作示范，并录制视频。该专家视频将被计时并评分，作为基准/目标绩效指标。所有训练过程均需录像，每次训练结束后由专家外科医生提供反馈。每位受训者最多进行八次训练尝试（图2）。对照组按常规轮转进行，不接受3D打印模型的额外训练。

4. 招募参与者

1. 招募具有腹腔镜手术基础（FLS）认证但无高级腹腔镜手术技能经验的新手外科医生，以及经验丰富的腹腔镜外科医生（>100 例 Nissen 胃底折叠术）。
2. 将新手外科医生随机分配至实验组和对照组。
3. 遵循培训课程大纲。

5. 评估性能

注意：由一名经验丰富的外科医生根据五部分手术特异性评分标准对所有培训视频进行评分，该评分标准借鉴并修改自先前的一项研究²³，详见《补充文件1》。

1. 在专家外科医生的监督下，对活体手术室（OR）操作表现进行最终评估，并使用相同的检查清单进行实时评价。
2. 此外，评估3D打印的LNF模型培训平台。

6. 数据分析

1. 测量所有结果，包括整体技术操作评分、特定操作步骤的清单评分、操作完成时间、学习曲线趋势以及3D打印喉神经框架训练平台的有效性。
2. 建立表格，汇总所有实验阶段和最终操作步骤的原始数据，并计算实验组与对照组的均值及标准差。
3. 采用适当的统计学方法进行数据分析。
4. 使用合适的绘图软件生成图表，以直观展示学习曲线的进展趋势及各项操作性能指标的比较结果。

讨论

These 3D printed models allow the training and assessment of essential key techniques crucial for an ideal LNF, such as crural closure with creation and execution of a fundal wrap around the oesophagus. This is crucial as studies have demonstrated that both the length and tightness of a fundoplication strongly influence the distal oesophageal sphincter pressure, potentially elevating it up to three times its preoperative levels, which may lead to dysphagia²⁵. As demonstrated, the resident's performance trajectory from the early training sessions to the final operating room performance showed significant improvement. The procedure time closely approached the expert's benchmark of 34 min. This marked improvement in technical proficiency was observed through iterative training sessions.

The 3D printed model offers the opportunity to practice procedure-specific advanced laparoscopic surgical skills in a safe, controlled environment^26,27. The use of these models for training purposes has gained traction over the past decade, with Zhu et. al. demonstrating their adequate realism, cost effectiveness, sustainability, and capacity for maintaining operative skills acquisition for training of medical students¹¹. Multiple studies have confirmed the realism and application of these models' fidelity through simulation programs, validity studies, and participants' feedback^21,22,28.

Analysis of training sessions revealed high standard deviations, especially during the earlier training sessions, training 1&<2, indicating performance inconsistencies across the assessed metrics. This variability highlights the importance of model design optimization, as some tasks involving intracorporeal suturing, such as crural closure score and mesh fixing score, were lower compared to fundoplication and inspection scores. This disparity reflects the increased complexity and learning requirements for specific technical skills within one procedure. Prior studies corroborate this relationship and offer evidence showing task-specific metrics could be used to differentiate between different surgeon levels. Xia et al. showed this distinction utilizing 3D printed models to simulate laparoscopic intracorporeal intestinal anastomosis using a modified anastomosis objective structured assessment of technical skills to help distinguish expert, intermediate, and novice surgeons²⁹.

The performance variability, especially in technical manoeuvres posed by intracorporeal suturing, highlights the need for procedural troubleshooting. For trainees struggling, expert proctors can ensure additional targeted drills on specific weaknesses, which is more effective than simple repetition. The design of the models allows for easy reusability and repeatable exercise, unlike animal organs and living tissue, which present storage challenges or reusability due to animal tissue friability, making them less cost-effective. With the 3D model, the peritoneal layer over the crura and the omentum, with the short gastric vessels, are the only things that should also be replaced after multiple practices. Furthermore, its low-cost production is maintained as the current material used is silicone, making it affordable³⁰. To address the model's reusability, we must consider its durability. While formal mechanical testing was not a part of this study's protocol, we made several observations based on informal experience during repeated training sessions. We noted that durability depended heavily on the participant's technique. For crural repair, a single model could typically accommodate approximately 10 suture placements before cumulative damage from needle penetration necessitated replacement. For fundoplication training, the limiting factor appeared to be mechanical stress from suture tension; the model generally withstood 6-8 instances of strong pulling force before showing signs of structural damage. Based on this observation, trainees should be instructed to apply moderate, controlled tension, as excessive pulling can cause premature model failure and does not reflect appropriate surgical technique. There is further research exploring the use of advanced materials like hydrogel polymers to further increase realism and enable the ability of perfusion and more advanced laparoscopic techniques, such as cautery^24,31. Nevertheless, the low maintenance cost per training, portability, and easy preservation ensure its accessibility to all training centres, schools, and hospitals.

The study's most critical validation suggests that the 3D-printed model training offers exceptional potential in bridging the gap between simulation-based training and actual operating performance. Previous studies have mentioned the need to showcase transferability as it would not only encourage usage but also offer great insight into its application in an actual live operation and patient outcomes³². It is imperative to acknowledge the inherent exploratory nature of utilizing 3D printed models in advanced suturing training. While statistically significant findings are encouraging, they necessitate cautious interpretation, requiring further validation with a larger cohort for more statistically definitive conclusions.

Possible limitations to these models include the design being as realistic as animal tissue; intricate anatomical features, which might be encountered in surgery, such as greater omentum, endothoracic fascia, endoabdominal fascia, mesoesophagus, and vagus nerve, were not included. However, certain design choices were deliberately made to increase the training's rigor and applicability. The curriculum focuses on hiatal hernia repair requiring mesh because mastering these complex techniques provides residents with the skills necessary to handle any type of hernia. Furthermore, the intentionally confined workspace prepares trainees for the most spatially challenging abdomens, ensuring their skills are robust and adaptable. Another question that arose was whether the number of laparoscopic cases or the quality of training made the residents better. Traditionally, the more laparoscopic cases a resident performs in their training, the better their skills get. However, as is evident, the duration spent in the skills laboratory is similarly invaluable, particularly relevant for residents with limited early exposure to advanced laparoscopic procedures³³.

Future research should also focus on a formal cost-effectiveness analysis, weighing the cost of this training program against the financial impact of longer OR times and managing postoperative complications. Furthermore, the ultimate goal is to validate that proficiency on this 3D model directly translates to improved patient outcomes, which would require a long-term study tracking metrics like operative time, complication rates, and hernia recurrence for patients of trained residents. Future work could involve standardized material fatigue analysis to provide quantitative data for the durability claim.

In summary, 3D printed models represent cost-effective, customizable, efficient tools that have a distinct effect in helping reach learning curves in a more expedited fashion. Impacting the clinical surgical education and patient outcomes.

材料

本文使用的材料清单

姓名	公司	目录编号	评论
GraphPad Prism 绘图软件	GraphPad Prism	Prism 10	用于图表生成 https://www.graphpad.com/scientific-software/prism/
无创抓钳	康济	101.096, Ø5.5×460毫米，或108Y.208（22毫米钳口）	标准腹腔镜器械 https://www.kangjimed.com/products
10毫米30度腹腔镜	康济	130.032A Φ5×300 mm 30°	标准腹腔镜设备 https://www.kangjimed.com/products
持针器  腹腔镜持针器	康济	101.029, Ø5×330mm	标准腹腔镜器械 https://www.kangjimed.com/products
剪刀 腹腔镜剪刀	康济	101.032A 直型	标准腹腔镜器械 https://www.kangjimed.com/products
硅胶	国苑	未指定	SLA 打印材料
SLA 3D 打印机	UnionTech	Lite800	大尺寸专业SLA 3D打印机 https://www.uniontech3d.com/products/lite-800-industrial-resin-sla-3d-printer/
统计软件 SPSS	IBM	版本 25.0	用于数据分析 https://www.ibm.com/products/spss-statistics
缝合线  Ethibond 缝合线	Ethicon	G680H，用于2-0 Ethibond	2-0 Ethibond，带 CT-1 针 https://www.ethicon.com/na/epc/search/platform/wound%20closure
超声波清洗机	丁宇	DY-020	用于清洁打印部件
紫外固化室	DHC	DHC48	用于后期处理
真空室	均载	5305-0609	用于后期处理