Microsurgical and 3D anatomy of the male retropubic space and urogenital diaphragm for the future prostatic surgery

Abstract

I. 서론: 전립선 암이 조기 진단된 경우에는 근치적 전립선 적출술이 완 치를 위한 가장 확실한 치료방법으로 추천이 되나 술 후 발기부전과 요 실금의 합병증이 문제가 되어왔다. 이런 문제를 해결하기 위해 많은 술 기적 발전들이 있어 왔으며 최근엔 치골 뒤 공간 보존 및 회음부를 통한 수술적 접근법 등의 방법이 관심을 받고 있다. 하지만 이러한 구조들에 대한 해부학적 연구가 많이 부족하며 논란이 있어왔다. 따라서 이 분야 의 정확한 해부학적 구조를 연구하고 이해하는 것이 수술 술기 발전과 합병증 감소에 도움이 될 것으로 생각되어 본 연구를 진행하게 되었다. II. 재료 및 방법: 연세대학교 의과대학에 유언하고 기증된 시신 중 관련부위의 수술 처치를 하지 않은 한국 성인 남자 시신 30구를 사용하였다. 6 구의 시신은 CT 촬영을 위한 루골 염색을 하였다. 통상의 방법으로 골반을 정리하여 치골전립선인대를 관찰하였으며 회음부의 얕은 샅공강, 샅힘줄중심, 깊은 샅공간의 구조를 순서대로 해부하여 관찰하였다. 루골로 염색한 표본은 통상의 CT 촬영 후 3차원 재구성하여 관찰하였으며 이후 해부를 진행하여 비교하여 보았다. 통계적 분석은 T 검정과 카이 스퀘어 검증을 사용하였다. III. 결과: 치골전립선인대는 크게 4가지형태로 분류가 가능하였고 한쪽 에 2개가 있는 경우도 25% 정도에서 관찰되었다. 붙는 위치는 치골의 하방 1/3의 매우 깊은 곳에 붙는 것을 확인하였으며 인대 사이의 거리는 평균 8.5mm 로 관찰되었다. 피부항문괄약근과 망울해면체근을 연결하 는 피부 중심 띠가 있는 것을 관찰하였고, 보조 얕은샅 가로근의 존재도 처음으로 관찰하였다. 샅힘줄중심의 구조가 두 층으로 되어 있으며 서로 연결되어 있음을 관찰하였다. 깊은 샅공간에 요도를 말발굽 모양으로 감 싸는 근육이 관찰되었고 요도로부터 앞쪽 경계까지 거리가 짧은 경우와 긴 경우로 구분되었으며 긴 경우엔 앞쪽에 근 섬유가 관찰되었다. 루골 염색 후 CT를 촬영한 것을 3차원으로 재구성한 후 구조를 관찰한 결과 얕은층의 근육들은 그 층과 결이 자세히 보여지며 분석이 가능한 것을 확인 할 수 있었다. IV. 결론: 치골뒤 공간에서 치골전립선인대는 다양한 수와 형태로 관찰 되었으며, 전립선을 단단히 붙잡아서 안정시키는 매우 중요한 구조임을 확인하였다. 60% 이상에서 관찰된 보조 얕은샅 가로근은 처음으로 보고 하는 근육이며 발기 시 음경을 지지해 주며 발기시 음경을 위쪽으로 올 려주며 뒤쪽으로 당겨주는 수축에 관여하는 역할을 하는 것으로 생각되 므로 그 기능에 주목할 필요가 있다. 깊은샅 가로근의 형태는 연속적이 지 않았으며, U자나 둥근 형태인 부분을 관찰하였다. 특히 요도 앞쪽 부 분이 좁고 근육이 없는 경우가 50%였으며, 이 경우 치골뒤 공간에서 구 조들을 단단히 지지해 주는 치골 전립선인대의 해부학적 중요성을 재조 명할 필요가 있으므로, 이를 보존하는 수술법을 시행하는 것이 수술 후 요실금 등을 예방하는데 필요하다고 생각한다. Introduction: The anatomical and functional importance of the puboprostatic c ligament (PPL) is increasingly recognized as essential to prevent complications of urinary incontinence and erectile dysfunction following radical prostatectomy. The Retzius-sparing technique was recently introduced as a method to preserve the PPL and neurovascular bundles. Detailed understanding of the precise anatomy of the PPL and its variations, and the neurovascular bundle, proximal urethra, prostate, and surrounding structures is imperative for both surgical planning and subsequent reconstruction to preserve urinary continence and erectile function. However, despite greatly affecting surgical outcomes, due to the difficulty of microanatomic study in these small and variable perineal muscles, there are few papers detailing the basic anatomy of the retropubic space. We conducted this study to further understanding of the anatomic variations of the PPL and perineal muscles in the retropubic space. We also conducted a three-dimensional (3D) computed tomography (CT) scanning image study using Lugol’s solution and compared reconstructed images with real samples. Materials and Methods: Cadavers of 30 Korean men who had not undergone surgery in the relevant areas, donated to Yonsei University College of Medicine, were used in this study. In each case, the pelvis was dissected using a conventional technique to observe the PPL. The superficial perineal pouch, perineal body, and deep perineal pouch were dissected for observation of their anatomical structures. Six samples stained with Lugol’s solution were scanned using a conventional CT system. Images were reconstructed into 3D images for comparison with the actual dissection. For statistical analyses, Student’s t-test and chi-square test were used. Results: Depending on the site of attachment, PPLs mostly (54.7%) had a linear form (Type I). Type II PPL and Type III PPL, which are connected to the tendinous arch were also observed. In some samples it was quite challenging to classify the type. Two PPLs were observed in 25% of all samples. The location of the attachment of the PPLs to the pubis was very deep in the lower third of the pubic bone. The medial border of the PPL was attached to a point which was, on average, 3.5 mm from the inner margin of the pubic body; while the lateral border was attached to a point, on average, 8.5 mm from the pubic body. In cases with more than two ligaments on one side, the distance between the bilateral ligaments was shorter than average. The ‘cutaneous central band’ in the perineum was observed to connect the bulbospongiosus muscle (BSM) and cutaneous external anal sphincter. The cutaneous central band was a narrow and deeply formed band of fibrous tissue. The fibrous band of the BSM that connects to the median raphe was observed to connect to the cutaneous fibers of the anal sphincter. The accessory superficial perineal muscle, which is located closer to the surface than the perineal membrane, was found in 61.5% of all samples. The perineal body consists of superficial and deep layers. The muscles within the deep perineal pouch were not in the form of a fascia with the muscles aligned in a horizontal fashion, but were hoof shaped (similar to the anatomy of the female compressor urethra muscle). The anterior side of the urethra was either short or wide. In cases of urethra with a wide anterior side, muscle fibers were also observed around the anterior. Three-dimensional reconstruction of CT scans of the muscles of the urogenital diaphragm revealed individual layers and patterns of the shallow layers which were able to be visualized and analyzed in detail on the 3D images. However, because the muscles in the deep layers were thin and exhibited various patterns, clear observation of their structure on the 3D images was limited. Conclusions: PPLs exhibited various morphologies which were classified into four different types based on the attachment type: Type I, which connects linearly from the pubic bone to the prostate, accounted for 54.7% of cases. Type II, which starts from the pubic bone and attaches to the prostate and prostate, tendinous arch, accounted for 37% of cases. Type III, which occurs when the ligaments from the pubic bone and the tendinous arch combine and attach to the prostate, accounted for 6.7% of cases. Type IV is characterized by multiple ligaments arising from the pubic bone to form a complex structure. Two PPLs were observed in 25% of all samples. The PPL was attached to the pubis very deep in the lower third of the pubic bone. The medial border of the PPLs attached to a point, on average, 3.5 mm from the inner margin of the pubic body, while the lateral border attached to a point, on average, 8.5 mm from the pubic body. In cases with more than two ligaments, the distance was shorter than the average. The fibrous connecting band between the anus and bulbar was observed superficially. This cutaneous central band was narrow and deeply formed with fibrous tissue. The fibrous band of the BSM that connects to the median raphe was observed to connect to the cutaneous fibers of the anal sphincter. The accessory superficial perineal muscle, which is located closer to the surface than the perineal membrane, was observed in 61.5% of all samples. The perineal body consists of superficial and deep layers. The muscles within the deep perineal pouch were not observed in the form of a fascia with the muscles aligned in a horizontal fashion but were hoof shaped (similar to the female anatomical structure of the compressor urethra muscle). The anterior side of the urethra was either short or wide. In cases with a urethra with a wide anterior side, muscle fibers were also observed around the anterior. Three-dimensional reconstructions of CT scans of the muscles of the urogenital diaphragm were performed. During image analysis, individual layers and patterns of the shallow layers were visualized and analyzed in detail on the 3D images. However, because the muscles in the deep layers were thin and exhibited various patterns, clear observation of their structure on the 3D images was limited.