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Surgical Management of Advanced Pelvic Cancer. Группа авторов
Читать онлайн.Название Surgical Management of Advanced Pelvic Cancer
Год выпуска 0
isbn 9781119518433
Автор произведения Группа авторов
Жанр Медицина
Издательство John Wiley & Sons Limited
Figure 1.2 Diagram from Bricker’s original article on urinary diversion demonstrating the evolution of various intestinal reconstruction techniques, including bilateral ureteric anastomosis to an isolated segment of sigmoid colon (A), terminal ileum with cecal reservoir (B), cecum with terminal ileum for urinary drainage tract (C), and contemporary ileal conduit (D). Copyright © 1950 Surgical Clinics of North America.
Source: Reproduced with permission from Elsevier [29].
Evolution of the Uretero‐Ileal Conduit
By the late 1950s, the ileal conduit became the established urinary diversion technique, and the high mortality and morbidity rates associated with pelvic exenteration began to decline [30]. In particular the procedure avoided the complications of implanting ureters into an intact colon and could be fashioned from ileum that was undisturbed by any pre‐existing radiotherapeutic field [31]. Despite these benefits, the complex nature of exenterative surgery made significant postoperative complications associated with urinary diversion were considered unavoidable, particularly the development of urinary fistulas [15, 32]. Brunschwig observed that, in patients who survived > 5 years “the most frequent subsequent cause of death is the deterioration of the diverted urinary tract” [33]. He advocated continuous surveillance of the urinary diversion and for the early use of temporary or permanent nephrostomy tubes for any evidence of obstruction [33].
Today, en‐bloc cystectomy is required in approximately half of all patients undergoing pelvic exenteration [34–37]. Despite much progress, postoperative urological complications remain a major cause of morbidity, prolonging hospital admission and impacting on quality of life [35]. Major complication rates between 9 and 24% are reported, with urinary leak rates occurring in 7–16% of patient [35–37]. Newer techniques for continent urinary diversion, such as the internal ileal pouch reservoir [38, 39], remain controversial. Alternatives like the Indiana pouch and the Miami pouch are suitable in highly selected patients [40, 41].
Subspecialization and Partial Exenteration
The synchronous abdomino‐perineal pelvic exenteration performed by the majority of exenterative units today was adapted from the technique for LARC described by Schmitz (Chicago, USA) in 1959 [42]. Over time it was recognized that the malignancy did not always extend to all of the adjacent pelvic organs. Consequently, partial exenteration was described, preserving urinary and/or rectal function. The later part of the twentieth century also saw the intensification of surgical subspecialization, driven in part by returning surgical veterans from World War II who had gained experience in specialties such as orthopedics and plastic and reconstructive surgery. The rapid subspecialization that ensued, combined with major advances in perioperative care, including intensive care and cardiac monitoring contributed to the progress seen in exenterative surgery (Figure 1.3) [2].
Figure 1.3 Evolution of pelvic exenterative surgery.
Composite Pelvic Exenterations
The development of compartmentalization of the pelvis and of partial exenteration resulted in more targeted approaches Bone resection was necessary for tumors involving the sacrum, coccyx, ischium, pubic symphysis, and/or ischiopubic rami [2]. Recent collaborative data show that bone resection (where needed) along with R0 margins are the most important factors influencing overall survival following PE for LRRC [5]. Disease proximal to the S1/S2 level was considered unresectable in many centers, and this represents another challenge [43–46].
Brunschwig and Barber reported a series of 28 patients, perioperative mortality was 29%, with five‐year survival of 15% [47]. These initial outcomes discouraged many from pursing en‐bloc bone resection. Research and better operative techniques developed for the management of sacral chordomas rekindled interest in composite PE in the 1980s [48]. Wanebo and Marcove (Charlottesville, USA) described the abdominal‐trans‐sacral approach for resecting LARC with sacral extension in 1981 (Figure 1.4) [49]. The initial dissection of the intrapelvic organs was accomplished through the traditional anterior approach followed by resection of the sacrum with the patient repositioned lying prone [46, 49]. Takagi and colleagues (Nagoya, Japan) encountered no postoperative mortality with this technique [50].
These outcomes stimulated research into the role of composite sacral resection for LARC and led to various units undertaking more radical resections, reporting morbidity rates between 40 and 91%, with < 5% perioperative mortality and five‐year survival of almost 50% [51–55]. In recent years, specialist units developed techniques for en‐bloc partial sacral resection. Hemisacrectomy, a procedure involving resection of the anterior cortex of the sacrum to preserve the sacral nerve roots, and segmental sacrectomy are alternatives [55–59].
Lateral Pelvic Sidewall Resection
Brunschwig and Walsh described “resection of the great veins of the lateral pelvic wall” to gain clearance for advanced gynecological tumors in the late 1940s [60]. However, extension of pelvic cancer into the pelvic sidewall was traditionally been considered contraindication to resection. Due to the technical difficulty of safely attaining an R0 resection margin. Efforts at vascular reconstruction were hampered by the procedure being frequently preformed in a grossly contaminated and often previously heavily irradiated field [61]. Due to these poor early outcomes, few undertook such radical resections until very recently [62].
Contemporary studies have reported en‐bloc resection of the pelvic sidewall for both locally advance and recurrent rectal cancer involving the lateral pelvic neurovasculature with good outcomes [63]. Similarly, extended lateral wall resection is possible in advanced gynecological tumors [64]. Some units are providing “higher and wider” resections for tumors involving the common and external iliac vessels [65, 66] and extending to the sciatic nerve and ischial bone [2, 57, 67]. Reported R0 resection rates range from 38 to 58%, with no perioperative mortality, and 96–100% long‐term graft patency [65, 66].
Perineal Reconstruction
In the original series, after the exenteration was performed, the pelvis was generally packed and allowed to heal by secondary intention. Later, surgeons closed the perineum in two layers, to prevent the small intestine prolapsing into the pelvic cavity [1]. In recent decades, various techniques for filling the “dead‐space” have been examined. The omental pedicle flap was reported as an adjunct in keeping the small bowel and urinary conduit from prolapsing into the pelvic cavity, with the hope of reducing fistula rates [68, 69]. In addition, the use of mesh reconstruction of the pelvic inlet, colonic advancement, and locoregional myocutaneous flaps have been advocated with varying degrees of success (Figure 1.5) [70–72]. The use of flaps in particular