A Fascial Reinterpretation of the Classical Female Pelvic Surgical Anatomy: Seeing Things from a Different Angle.

STUDY OBJECTIVE

The classical surgical anatomy of the female pelvis was born with radical hysterectomy [1] and focused on the pivotal role of the lateral parametrium, a conceptually complex structure, an artifact of surgical anatomy [2] without which the whole classical model would collapse. Here, using natural planes, we tried to simplify the puzzle of the virtual spaces surrounding this structure [3,4]. With the aim of better conceptualizing the classical model of the female pelvic surgical anatomy, we broadened its perspective, which had been narrowly focused on the historic gynecologic setting, by developing a comprehensive model of pelvic retroperitoneal compartmentalization. This dissection was based on the invariable anatomic (fasciae) rather than the surgical-anatomic (parametrium) structures and aimed at providing a holistic, more user-friendly approach intended for surgical and educational purposes [5]. Because each compartment has its own surgical function (hence the name), the excavation of a single compartment may be used as a rational guide to tailor surgery to the site of the pathologic condition to be treated or the type of procedure required, whereas the compartments' sequential development may be useful in planning surgical strategies. Redefining the classical model according to the anatomic fascial planes of dissection potentially allows for an intrinsic surgical reproducibility, minimizing dissective bias. A reinterpretation of the known anatomy is required to enhance education. The breaking down of such a complex system (the pelvis) into smaller parts (compartments) will hopefully provide a useful guide for conceptualization and navigation; surgical navigation requires a holistic mental map and a few invariable anatomic reference points or landmarks.

DESIGN

A step-by-step laparoscopic demonstration of the fascial model, developed on a fresh frozen female pelvis, and its correlation with the classical female retroperitoneal surgical anatomy.

SETTING

Cadaver Laboratory, Department of Legal Medicine, University of Turin.

INTERVENTIONS

The first part of the video shows the progressive development of the 3 hemicompartments in the right hemipelvis and of the fourth median compartment after the identification of 3 invariable anatomic reference points: the obliterated umbilical artery, the ureter, and the sacrouterine ligament as superficial landmarks of 3 deeper fascial-ligamentous structures: the umbilicovesical fascia, the urogenital-hypogastric fascia, and the sacropubic ligament, respectively (Figure 1). The areas delimited by the aforementioned deep fascial ligamentous structures have been designated as compartments: • the right parietal hemicompartment, so called because it is bordered by the sidewall of the pelvis, lateral to the umbilicovesical fascia • the right vascular hemicompartment, so called because of the presence of the internal iliac vessel's visceral branches between the umbilicovesical fascia and the urogenital-hypogastric fascia • the visceral compartment, so called because it contains the pelvic organs between the sacropubic ligaments • the right neural hemicompartment, so called because of the presence of the organ-specific vegetative bundles, medial to the urogenital-hypogastric fascia. The second part of the video describes the retrorectal, presacral, and retropubic connection areas between the neural, vascular, and parietal hemicompartments of each hemipelvis, justifying their overall crescent shape. Finally, the spaces of classical surgical anatomy included in each hemicompartment are listed not only according to their anatomic criterion, but also according to their functional criterion. In fact, the parietal compartment should be developed for the evaluation of the pelvic lymph node status or during exenterative and urogynecologic procedures. The vascular compartment must be prepared when sectioning of the vascular visceral pedicles at their origin is required. Development of the neural compartment is required whenever visceral neural components are to be spared. The visceral compartment has to be developed for complete organ mobilization and exposure.

CONCLUSION

Taken as a whole, our 4-compartment model of pelvic anatomic surgery is intended for use in planning and optimizing surgical strategies. Moreover, it is potentially able to simplify surgical teaching and training, allowing the fitting together of puzzle-like pieces of disjointed organ-specific retroperitoneal spaces according to their function (Figure 2). The correlation of this approach to clinical outcomes is still being determined.