Prior radiation therapy is associated with fibrosis and delayed healing. An appreciation of potential postoperative problems secondary to these factors is important in planning the surgical extirpation and reconstruction. For example, in a patient who requires mastectomy after failed breast-conserving surgery, the zone of tissue damage from the original radiation therapy can be assessed by reviewing the port and boost site films or by examining the irradiated site for tattoo marks used to align the radiation field. Plans for resection of heavily irradiated tissues should be made preoperatively in concert with the reconstructive surgeon, and the relative increased risk of postoperative problems should be discussed with the patient. This evaluation should include the type of tissue to be transferred, analysis of potential donor and recipient sites and vessels, and assurance that the appropriate microvascular equipment is available, in the event that it is needed during surgery.
Pathologic confirmation of the diagnosis
The treatment of cancer is based almost exclusively on the organ of origin and, to a lesser degree, on the histologic subtype. Unless the operative procedure is being performed to make a definitive diagnosis, review of the pathologic material is needed to confirm the diagnosis preoperatively.
There are few exceptions to this doctrine, and it behooves the surgeon to have a confirmed diagnosis, including the in situ or invasive nature of the cancer, prior to performing an operation. This tenet assumes paramount importance when one is performing procedures for which there is no recourse once the specimen is removed, eg, laryngectomy, mastectomy, removal of the anal sphincter, and extremity amputation.
Ironically, in some situations, a preoperative or intraoperative diagnosis cannot be confirmed, despite the fact that the preoperative and intraoperative physical findings, laboratory data, and radiologic studies (pre- and intra-operative) overwhelmingly suggested the cancer diagnosis. The classic example of this dilemma is the jaundiced patient with a firm mass in the pancreatic head. The Whipple procedure (pancreaticoduodenectomy) causes significant morbidity but is required to make the diagnosis and treat the cancer. In any of these situations, the preoperative discussion with the patient must include the possibility that the final diagnosis may be a benign lesion.
The principles of resection for malignant disease are based on the surgical goal (complete resection vs debulking), functional significance of the involved organ or structure, and the ability to reconstruct the involved and surrounding structures. Also important are the technical abilities of the surgeon or availability of a surgical team, adequacy of neoadjuvant and adjuvant therapies, and the biologic behavior (local and systemic) of the disease. Although “operable” is used to describe the physiologic status of the patient, the definition of “resectable” varies, and this term can be defined only in the context of the aforementioned modifying parameters.
A wide excision includes the removal of the tumor itself and a margin of normal tissue, usually exceeding 1 cm in all directions from the tumor. The margin is variable in a large, complex (multiple tissue compartments) specimen, and the limiting point of the resection is defined by the closest approximation of cancerous tissue to the normal tissue that is excised.
Wide margins are recommended for tumors with a high likelihood of local recurrence (eg, dermatofibrosarcoma protuberans) and for tumors without any reliable adjuvant therapeutic options.
Breast The use of adjuvant radiation therapy has permitted the use of breast-conserving surgery, which limits the excision of wide margins of normal breast tissue.
Colon and rectum For carcinoma of the colon and rectum, the width of excision is defined by the longitudinal portion of the bowel and the inclusion of adjacent nodal tissue. The principles of wide resection require removal of normal bowel (including at least 5 cm of uninvolved tissue), the associated mesenteric leaf, and adjacent rectal soft tissue (mesorectum). Current guidelines require the removal of 12 to 15 nodes for evaluation.
This general principle has been modified in the distal rectum, where lateral margins are maintained using the principles of mesorectal excision, and longitudinal bowel margins of 2 cm are accepted. This modification reflects the emphasis on functional results (ie, maintenance of anal continence) and the availability of neoadjuvant (preoperative chemotherapy and irradiation) therapy to reduce the tumor size and resectability and postoperative adjuvant radiation therapy and chemotherapy to improve local control.
No touch technique
This principle is based on the concept that direct contact with and manipulation of the tumor during resection can lead to an increase in local implantation and embolization of tumor cells, respectively. Theoretically, the metastatic potential of the primary lesion would be enhanced by the mechanical extrusion of tumor cells into local lymphatic and vascular spaces. There may be some validity to this theory with respect to tumors that extend directly into the venous system (eg, renal cell tumors with extension to the vena cava) or those that extensively involve local venous drainage (eg, large hepatocellular carcinomas).
Extensive palpation and manipulation of a colorectal primary have been shown to result in direct shedding of tumor cells into the lumen of the large bowel. The traditional strategy to lessen this risk was to ligate the proximal and distal lumen of the segment containing the tumor early in the resection. These areas were then included in the resection, limiting the contact of shed tumor cells with the planned anastomotic areas.
Neither of the previous theoretical situations (ie, manipulation of the tumor and direct contact of the tumor with the anastomotic area) has been definitively tested in controlled, prospective, randomized trials. However, the risk-benefit ratio should favor adherence to the general principles of minimal tumor manipulation, protection of the anastomotic areas, and exclusion of the resection bed from potential implantation with tumor cells.
The minimally invasive surgical techniques introduced approximately 20 years ago were incorporated into the surgical procedures for a non-oncologic scenario—cholecystectomy, hiatal and inguinal hernia repair, and treatment of benign diseases of the female reproductive tract. Transfer of the technology to the oncologic setting was met with resistance, as questions of technical (number of nodes resected and less tactile input during resection) and therapeutic (local control, disease-free survival, and overall survival) equivalence were raised.
Careful clinical research has answered these initial reservations for colon cancer and to a lesser degree for rectal cancers. Results from a prospective randomized trial reported by the Laparoscopic Colectomy (LC) trial group documented that although the laparoscopic operations took longer than the open procedures (150 vs 95 minutes), there was no difference in the margins obtained, the 30-day mortality, or the complication rate. LC resulted in a shorter overall hospital stay (4 vs 5 days) and less use of parenteral narcotics (3 vs 4 days) than the open procedure. There was no difference identified for the oncologic outcomes of disease-free recurrence or overall survival.
Examples in colon cancer will serve as paradigms for the study of other tumors. The introduction of the da Vinci robotic system has opened new areas for technical investigation and evaluation of operative outcomes. Expansion of minimally invasive techniques (laparoscopic and robotic-assisted), with preservation of oncologic principles and improvement in patients' quality-of-life outcomes, will drive surgical interventions.
Early surgical oncologic theory proposed that breast cancer progressed from the primary site to the axillary lymph nodes to the supraclavicular nodes and nodes of the neck. This theory led to the radical surgical approach that included resection of all of the breast tissue and some or all of the above-noted draining nodal basins (ie, modified radical, radical, or extended radical mastectomy).
Absent from this approach was an appreciation of the nodes not only as a deposit of regional metastatic disease but also as a predictor of systemic disease. Modern treatment approaches view nodal dissection as having a triple purpose: the surgical removal of regional metastases, the prediction of prognosis, and the planning of adjuvant therapy.