John Northover returned to deliver a keynote lecture on multidisciplinary pelvic surgery. Updates on polyp management, oncology and IBD were among the sessions.
The miserable outcome for patients whose rectal tumours cannot be resected drives the pelvic cancer team to strive wherever possible to downstage tumours and attempt resection. Careful clinical assessment and radiological imaging allows a treatment plan to be formulated using combined chemoradiotherapy and subsequent surgery. Radical resections such as total pelvic exenteration and sacrectomy can be successfully performed in appropriately selected patients. Experienced teams can obtain reasonable outcomes with acceptable levels of morbidity and low operative mortality. For patients who have to live with a tumour in situ palliative approaches can offer incremental improvements with control of pain and discharge being a key component in improving and maintaining quality of life.
The assessment of advanced tumours has been helped by major improvements in radiological imaging allowing more objective determinants of staging and better planning for multimodality treatment. Whether an advanced tumour is deemed resectable is subject to many variables but the consequences of a surgeon labelling a patient “inoperable” are profound. Living with a rectal cancer in situ especially in the absence of metastatic disease inevitably leads to a miserable state of uncontrollable pain, tenesmus, discharge and infection.
Clinical assessment requires an examination under anaesthetic (EUA) by a surgeon experienced in managing advanced disease. Fixity of the tumour to the sacrum, pelvic side walls and adjacent organs must be determined and differentiated from tethering. Frank invasion of soft tissues of the pelvic floor and perineum needs to be mapped in order to plan for reconstruction following excision in continuity with the tumour. In the authors experience this detailed examination with intraoperative endoanal ultrasound(EAUS) where appropriate, complements radiological assessment of local invasion leading to the most accurate evaluation of T stage. Resection may necessitate radical surgery with removal of adjacent organs and exentrative procedures that are beyond the scope of individual surgeons who have limited experience in dealing with advanced tumours. Seeking a second opinion on behalf of the patient reflects professional competence rather than defeat. Categorising a tumour as “inoperable” following EUA should really be reserved for cases fixed to the sacrum, or bulky tumours with lateral extension to the pelvic side walls and limited mobility.
For evaluating advanced T3 and T4 tumours it may be necessary to use all imaging modalities (EAUS, CT, MR, PET) and it is essential that the radiologist has experience in pelvic imaging and is familiar with changes that result from previous surgery and radiotherapy. It is helpful if the radiologist is made aware of prior resections and treatments and given information of the findings at EUA. The radiologist is a crucial member of the multidisciplinary team managing the patient.
Inoperable rectal tumours can be downstaged and rendered operable following treatment with long course radiotherapy alone or combined chemo-radiotherapy (CRT). Following these treatments the extent of surgery may be reduced significantly, allowing organ salvage or even reconstruction after tumour resection. Overall the evidence suggests that for patients with good performance status and limited co-morbidity, CRT leads to shrinkage of T3/4 tumours offering the potential for less radical and more curative resections in locally advanced disease: 45-65% of fixed rectal tumours can be downsized and resected following RT alone but almost half will develop local recurrence. It is essential that the patient is re-evaluated following CRT using MR scanning and further EUA. There is increasing evidence that deferring resection for 10-12 weeks following CRT may increase respectability rates and decrease morbidity.
A few centres have facilities for intraoperative radiotherapy(IORT) where a radiation boost can be applied directly to the tumour bed following resection. In a study of patients with fixed rectal tumours undergoing preoperative radiotherapy and radical resection alone, versus additional IORT, local recurrence was reduced from 11% to 3%.
The surgical procedure will vary depending on disease extent and whether the tumour is confined to the posterior pelvis or involving the central and anterior pelvic structures. Despite the radicality of the surgery required, in experienced hands outcomes of 30-40% five year survival with low operative mortality can be achieved with exenterative procedures for advanced central tumours. Posterior tumours may extend into the bony pelvis and careful assessment with MRI will outline the extent of bony involvement. Sacrectomy should only be undertaken with curative intent with a S2/3 level as uppermost. Lateral extension is associated with a poor prognosis and has a low resectability and cure rate.
Radical excisional surgery is usually offered when the disease is confined to the pelvis but may also be justifiable where the metastatic load is minimal and the patient is physically well. Excision may be the best means of achieving pain relief and eliminating sepsis. In the male, total pelvic exenteration (TPE) is usually required particularly in anterior or circumferential tumours where attempts at dissection in the standard plane would risk leaving tumour on the back of the seminal vesicles and prostate and is associated with early recurrence. In selected cases it is possible to do a proctectomy or abdominoperineal rectal resection with an en-bloc radical prostatectomy achieving clearance without breaching the oncological plane. Reconstruction of the urinary tract avoids the need for an ileal conduit and second stoma. Female patients have the advantage of the gynaecological barrier and posterior clearance is often feasible particularly if the patient has not had a hysterectomy. It is usually possible to preserve the anterior vaginal wall opening the vagina anteriorly separating the middle and posterior pelvic organs.
Perineal reconstruction is usually not necessary for rectal tumours as the radiation field is concentrated on the rectum. It is advisable however to undertake mobilisation and placement of the omentum in the pelvis following long course CRT as it protects against small bowel prolapse, entrapment, fistulae, chronic sepsis and perineal sinus. Myocutaneous flaps should be planned for where there is a large low anorectal tumour and/or a weak pelvic floor. Rectus abdominis(TRAM), gracilis and gluteal flaps can all be used, the advantage of the later two, being retention of the anterior abdominal wall musculature for support of urinary and colonic stomas. It is essential that morbidity associated with reconstruction is kept to a minimum as flap failure leads to major distress and extended hospital stay. Where colorectal surgeons choose to undertake these procedures they must be able to demonstrate outcomes comparable with specialists in reconstructive surgery.
Further Reading
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Course Fee: £240
Mr J HartleyConsultant SurgeonAcademic Surgical UnitCastle Hill HospitalCottinghamEast YorkshireHU16 5JQ