href="#ulink_e04c69ae-297b-59e7-bb9e-9d056f80bdb1">Table 3.2 The St. Mark’s roadmap approach for assessment of pelvic tumor anatomy and resection margins.CategoryStructures and assessmentSurgical considerationsVisceral structuresRectum Uterus/vagina Prostate/seminal vesicles Bladder Base of penisAPER +/− excision of seminal vesicles +/− penile base excision Posterior/total pelvic exenterationUretersInvolvement relative to ureteric orificePartial ureterectomy +/− reimplantation/reconstructionVesselsCommon/external iliac arteriesVascular resection +/− reconstructionInternal iliac arteries: involvement relative to origin of SGALigation proximal/distal to origin of SGABony/ligamentous pelvisPubic bones + symphysisPubic bone resectionSacrum and presacral fasciaHeight of most proximal involvement relative to sacral promontoryExtent of subperiosteal dissection + level of sacral transectionDepth of cortical involvementSubperiosteal dissection HiSS Full thickness sacrectomyWidth of involvement relative to sacral foraminaWidth of HiSS or asymmetrical sacrectomySacropelvic ligaments and ischial spinesInvolvement of sacrospinous/sacrotuberous/ischiococcygeal ligaments (SLAM) + lateral extent relative to ischial spineResection of SLAM ELSiEDepth of involvement of ischial spineELSiE +/− extension into/toward acetabulumNervesL5/S1 nerve rootsResection of lumbosacral trunk with motor deficitS2/3/4 nerve rootsResection with sensory deficitMain trunk of sciatic nerve in sciatic notchPreservation or partial/total excision (as part of ELSiE)MusclesObturator internusResection as part of sidewall excisionPiriformisMedial aspect resected transabdominally (Sub)total resection requires ELSiEAPER, Abdomino‐perineal excision of the rectum;SLAM, term denoting the complex of sacropelvic ligaments: sacrospinous, sacrotuberous, and ischiococcygeal;SGA, superior gluteal artery;ELSiE, extended lateral sidewall excision;HiSS, high subcortical sacral resection.
Posterior: tumor infiltration of presacral fascia (S1–S5) without cortical invasion; S1/2 nerve roots clear
Lateral: tumor infiltration of pelvic sidewall fascia with sparing of internal and external iliac vessels; sacrotuberous and sacrospinous ligaments spared but right piriformis muscle infiltrated by tumor
Infralevator: tumor involvement of right levator
Anterior urogenital area/perineum/retropubic space: unaffected
In its conclusion, the compartment‐based report states that resection would require removal of the tumor from the anterior compartment above and below the peritoneal reflection, posterior compartment from S1 down, right lateral compartment, and right infralevator compartment.
This compartment‐based approach provides information on tumor extent, provides prognostic information, and helps determine if the local surgical team has the requisite skills to proceed with excision [36, 37].
In the roadmap approach, the relevant components from Table 3.2 were assessed and “translated” into a proposed surgical plan shown in Table 3.3 and Figures 3.1–3.7. Ultimately, the road map constructed by this multidisciplinary approach was for high sacrectomy with right ELSiE and either posterior exenteration (with the patient accepting a non‐functional bladder) and right ureteric reimplantation or total pelvic exenteration. The detailed report proposed was as follows: en‐bloc high sacrectomy at the S1/2 junction by dissecting down in the subperiosteal plane from the sacral promontory for 38 mm before transecting the sacrum, taking care to preserve the right L5 nerve root but including the S1 nerve root in the resection. Along the right pelvic sidewall, the internal iliac artery should be ligated proximal to the origin of the SGA and excised with the specimen. The abdominal dissection should stop at the upper level of the sciatic notch to avoid breaching the structures which need to be resected as part of the ELSiE. From the prone position, on the right side all gluteal tissues should be mobilized off the posterior aspect of the SLAM and piriformis muscle to the tip of the ischial spine; after transection of the ischial spine, the distal aspect of the obturator internus muscle should be excised.
Table 3.3 Construction of the roadmap for R0 resection in patient 1.
| Category | Structures and assessment | Surgical considerations | Figures |
|---|---|---|---|
| Sacrum and presacral fascia | Presacral fluid collection surrounded by rim of fibrosis, starting 38 mm from sacral promontory | Subperiosteal dissection from promontory down to point of sacral transection 38 mm distally (S1/2 junction) | 3.1 |
| No discernible plain between presacral fibrosis and anterior sacral cortex | Full thickness sacrectomy | 3.1 | |
| Nerves | Right L5 nerve root free and separate from tumor No discernible plain between right S1 nerve root and tumor/fibrosis | Preservation of right L5 nerve root with resection of S1 nerve root leading to partial motor deficit | 3.2 |
| Sacropelvic ligaments and ischial spines | Right SLAM complex grossly involved by tumor including insertion into ischial spine | Right ELSiE taking the tip of the ischial spine | 3.3 |
| Muscles | Distal aspect of right obturator internus muscle undistinguishable from tumor/fibrosis | Resection of distal aspect of right obturator internus as part of ELSiE | |
| Right piriformis muscle grossly tethered by tumor/fibrosis | Resection of right piriformis as part of ELSiE | 3.4 | |
| Vessels | Tumor extending to origin of right SGA | Right internal iliac ligation proximal to SGA origin | 3.5 |
| Visceral structures | Primary rectal tumor tethering uterus and both ovaries Bladder not directly involved but completely denervated due to required S1/2 sacrectomy | Total pelvic exenteration preferable but bladder preservation possible (to be discussed with patient) | 3.6 |
| Ureters | Distal right ureter indistinguishable from tumor/fibrosis | If bladder to be preserved: Proximal division of right ureter at level of pelvic brim, distal division just proximal to the ureterovesical junction Right ureteric reimplantation | 3.7 |
Figure 3.1 Sagittal MRI showing presacral fluid collection surrounded by a thick rim of fibrosis abutting the anterior sacral cortex; the extent of subperiosteal dissection to the level of planned sacral transection is indicated.
This roadmap was strictly followed intraoperatively and a total pelvic exenteration with en‐bloc S1/2 sacrectomy and right ELSiE was performed, resulting in R0 resection and very limited impact on patient mobility.