E-Book, Englisch, 216 Seiten, ePub
Merlini / Martin Multiorgan Resections for Cancer
1. Auflage 2006
ISBN: 978-3-13-257841-8
Verlag: Thieme
Format: EPUB
Kopierschutz: 6 - ePub Watermark
Advanced Surgical Techniques
E-Book, Englisch, 216 Seiten, ePub
ISBN: 978-3-13-257841-8
Verlag: Thieme
Format: EPUB
Kopierschutz: 6 - ePub Watermark
Marco Merlini
Zielgruppe
Ärzte
Autoren/Hrsg.
Fachgebiete
Weitere Infos & Material
1 Basic Principles & Anatomy
1 Surgical Indications
2 Surgical Principles
3 Posterior Aspect of the Abdominal Viscera and Retroperitoneum
2 Upper Gastrointestinal Tract
4 Esophagus
5 Stomach
6 Pancreas
7 Liver and Bile Duct
3 Lower Gastrointestinal Tract
8 Right Colon
9 Left Colon
4 Pelvis
10 Abdominoinguinal Incision for Pelvic Side Wall Tumors
11 Strategies for Advanced Pelvic Malignancy
12 Pelvic Surgery
5 Peritoneum
13 Peritonectomy for Carcinomatosis, Sarcomatosis, and Mesothelioma
6 Retroperitoneum
14 Retroperitoneal Resections for Sarcomas Invading Adjacent Organs
1 Surgical Indications
Marco P. Merlini and Michael Dusmet
The indications for multiorgan resections are complex to define because there are many variations in histologic type, pattern of invasion, number of organs involved, and situation in the peritoneal cavity or retroperitoneum. The timing of surgery and chemo- and/or radiotherapy (neo-adjuvant versus adjuvant) will also vary from case to case. Finally, the experience of the surgical team will also play a role.
More than in any other case a multidisciplinary approach to these tumors is essential. Medical oncologists, radiation oncologists, surgeons, and radiologists all have important contributions to make and multi-modality therapy is frequently indicated.1, 2
This chapter provides an overview of the principles of this challenging and difficult field of surgery. The tumors we will be discussing are by nature locally advanced. The twin goals in every case must be to achieve a complete resection and a curative resection, which are not necessarily synonymous, as shall be discussed throughout. Incomplete resections are of little or no benefit to the patient for they submit the patient to all the potential morbidity and mortality of the procedure without any of the benefit (i. e., the chance to be cured). The patient must be fit for the planned treatment for it is axiomatic that the patient can only be cured if he/she survives it. There is no place for expression of the surgical ego in this field of surgery and the desire to perform a “fantastectomy” must be banned. The only rationale must be a cold calculation of the true risks and benefits of the procedure. The patients that truly benefit from these complex procedures are an extremely highly selected group and improper patient selection will invariably lead to unacceptable outcomes, both in terms of morbidity/mortality and survival.
Rationale
It has been shown that often the prognosis following the complete resection of a tumor that invades an adjacent organ is similar to that of a tumor which simply breaches the serosa. In gastric cancer, Bozzetti et al. examined the outcome of 143 tumors with invasion of an adjacent structure. The 5-year survival following complete resection of a pT4 N0 tumor was 29%, whereas this was 21% for pT3 N0 tumors.3 A possible explanation might be that extension into a neighboring structure prevents shedding of cancer cells from the serosal surface and peritoneal carcinomatosis. Local invasion is certainly less ominous than loco-regional or distant spread. In the series of Bozzetti et al. lymph node involvement had a quite substantial negative impact on survival-the 5-year survival for pT3 N1 and pT4 N1 tumors were respectively only 2 and 5%. This is analogous to what has been shown in nonsmall cell lung cancer where much larger series are available. The 5-year survival following complete resection of a pT3 N0 tumor with chest wall invasion is 40-50%, which is similar to that of a pT1/2 N1 lesion and considerably better than the only 25-40% 5-year survival of patients with true minimal N2 disease. The 5-year survival of patients with completely resectable (as opposed to true minimal) N2 disease is only 9%.
Indications
Intraoperative Discovery
Despite careful preoperative evaluation the intraoperative staging, which is the mandatory first step in any cancer resection, will show invasion into an adjacent structure in a certain number of cases. There are areas where the normal close approximation of structures can make it impossible to accurately assess juxtaposition and invasion by CT or MRI. Again this situation is much more codified in thoracic surgery than in general surgery. In thoracic oncology (nonsmall cell lung cancer) it is commonly thought that in an ideal world the surgeon should have a 5% “open and shut” rate, i.e., cases where the intraoperative staging has shown a more advanced stage than predicted leading to the decision not to proceed with the planned resection. This prevents some patients being denied curative surgery due to over-interpretation of the preoperative imaging. A higher rate denotes an excessively cavalier attitude on the surgeon's behalf. In the abdomen these areas of juxtaposition vs. invasion, which can be delicate to assess on imaging, are the bile duct and the portal vein, the gastric antrum and the head of the pancreas, and the unciform process of the pancreas and the confluence of the mesenteric and portal veins. If this situation is anticipated or encountered it is essential that the patient should be cared for by a surgeon who feels comfortable performing these complex operations. Otherwise the patient should be referred to a tertiary referral center for the resection. What is essential is that the resection should be complete and that during the dissection the areas of tumor adhesion must not be meddled with surgically but encompassed by adequate resection margins.
Surgery after Induction Therapy
The term primary (chemo-, radio-, or chemo-radio) therapy implies that the object is to downstage the tumor so as to render an irresectable tumor resectable. Neo-adjuvant therapy is intended to improve the 5-year survival of a technically operable tumor which has an inherently poor prognosis. Induction therapy comprises both primary and neo-adjuvant therapy. However, the terms are often used interchangeably.
When primary tumors of the esophagus,4–6 the stomach,7–11 the ovary,12–14 the rectum,15,16 or the pancreas are irresectable at the time of presentation induction, therapy is often considered to try to downstage the tumor.17–19 If there is a complete or partial response resection can be considered. Again it is worthwhile to remember that the definition of a partial response in many protocolsis a reduction in size of >50% for the sum of the two greatest diameters. In some cases a high (fivefold, for example) reduction of the SUV on the PET scan can be used as a surrogate marker for tumor response to induction therapy. If the dissection planes between the organ of origin of the tumor and the involved second organ are not clear cut and clearly tumor free then a multiorgan resection should be performed.
In every case these operations require careful planning so that an appropriate team and instrumentation are available at the time of surgery. If a vascular substitute may be required (greater saphenous vein, internal jugular vein for example) the patient is positioned, prepped, and draped in preparation for this after ensuring that the anesthesiologist has not attempted to put lines into the vessel. Likewise at times ureteral catheters will need to be placed by cystoscopy prior to starting the operation itself.
Induction therapy followed by surgery is a potentially morbid combination that requires fit patients. The upper age in most trials is usually 70 years and this is worth remembering even outside of a trial setting. Even more than for multiorgan resections alone, patient selection is of paramount importance to obtain acceptable results.
Tumors which are Poorly Responsive to Chemo- and Radiotherapy
Some tumors, such as bile duct adenocarcinomas and retroperitoneal sarcomas do not respond to induction therapy in a satisfactory or reliable manner. This expose the patient to a significant risk of tumor progression during induction therapy, which could mean progression to a completely irresectable stage. These are always very difficult situations to deal with both in terms of treatment decisions and the technical aspect of the resection itself. These are the operations which are liable to present the greatest technical challenges and therefore require the highest amount of preoperative planning and preparation. It is also essential that during the consent process the patient (and his/her family) is made aware not only of the risks of surgery, but also of the not insignificant risk of finding an irresectable tumor at the time of surgery which mandates retreat without resection (the so-called “open and shut” case).
Conditions
Below is the check-list of conditions which must be fulfilled for a patient to be a candidate for a multiorgan resection.
The Patient's General Condition
These are long, complex, occasionally hemorrhagic, sometimes staged procedures which put considerable physiologic stress on the patients. A careful and complete history is the mandatory first step in the evaluation of the patient and it is essential to quantify or rule out major organ dysfunction. Obviously routine blood work will be obtained to assess liver and kidney function. The threshold to obtain specialized investigations such as full pulmonary function tests, echocardiograms, thallium scans, or even coronary angiograms should be low. The overall performance score should be assessed. We use the Eastern Cooperative Oncology Group (ECOG) score which goes from 0 (no limitations whatsoever) to 4 (fully bed-bound).20 Candidates for these complex operations will ideally all be in categories 0-2.
Distant Metastases
Appropriate investigations must be performed to rule out distant metastases. These will include CT of the chest, abdomen and pelvis, MRI of the brain (or at least CT if MRI is not readily available), PET scan if appropriate. If a PET scan is performed a bone scan is not necessary (PET has both higher sensitivity and specificity than the bone scan for bone metastases if the primary tumor is FDG avid). As a general rule the presence of distant metastases is an absolute contraindication to multiorgan resection. However, there is at least one report of thermoablation of limited liver metastases with...
