40 Complications of Oral Cancer Surgery
Summary
Surgery for oral cavity carcinoma is a delicate balance between oncologic control and functional preservation. For each procedure, intraoperative awareness of anatomy and careful clinical observation postoperatively helps prevent, identify, and effectively manage complications. Though some complications are expected as sequelae of surgery, comprehensive knowledge of all possible consequences improves how physicians communicate postsurgical expectations with patients and manage complications when they arise.
40.1 Introduction
Nearly one-third of head and neck cancers occur in the oral cavity. 1 , 2 Surgery is the preferred initial treatment over radiation for oral cavity cancers. 3 Analysis of the Surveillance, Epidemiology, and End Results (SEER) database supports the improved overall survival and disease-specific survival of primary surgery over radiotherapy for both early- and late-stage tumors. 4 , 5 Each oral cavity cancer resection and reconstruction is a delicate balance between disease eradication, functional restoration, and expected sequelae, with the risks of possible complications. Complications may include bleeding, hematoma, inadvertent trauma, seroma, infection, wound dehiscence, mucocele, ranula, submandibular and parotid duct iatrogenic stenosis with sialadenitis, unsatisfactory scar, inadvertent or expected temporary or permanent nerve injury, tooth injury or loss, dysarthria, dysgeusia, dysphagia (with difficulty chewing and/or difficulty swallowing), oral or facial sensory loss, xerostomia, thickened saliva, salivary fistula, oral cutaneous fistulae, oral-sinonasal fistulae, skin graft loss, failure of pedicled flap or free flap, facial cosmetic alteration, osteoradionecrosis (ORN) of the mandible or maxilla, infected or extruded hardware, anesthesia-related cardiopulmonary problems, or even death in rare cases. In this chapter, we discuss the sequelae and complications associated with oral cavity cancer resection and reconstruction. The expected sequelae, varying with the extent of the resection and degree of reconstruction, may include nerve injuries, tooth loss, functional impairment, sensory loss, dry mouth, and/or cosmetic changes. Going forward, such sequelae will be referred to as complications for the purpose of this discussion.
40.2 Epidemiology
40.2.1 Incidence
Fully determining complication rates for any surgical procedure is a challenge given varied studies with heterogeneous reporting and differing definitions of complications. Although in experienced hands morbidity can be fairly low, complication rates for oral cavity carcinoma surgery have been reported to be as high as 20 to 50%. 6 , 7 Complications are likely less common in lower-stage cancers for which less extensive operations are generally indicated. ▶ Table 40.1 lists incidence rates reported by various studies of complications following oral cavity cancer surgery.
|
Complication |
Rate |
Reference |
|
Reoperation |
9.6% |
Schwam et al (2015) 8 |
|
Infection |
22.7% 8.5% 6.6% |
de Melo et al (2001) 6 Lodder et al (2015) 7 Schwam et al (2015) 8 |
|
Surgical site |
4.7% |
Schwam et al (2015) 8 |
|
Dehiscence |
20.9% 1.6% |
de Melo et al (2001) 6 Lodder et al (2015) 7 |
|
Flap failure |
2.2% |
Schwam et al (2015) 8 |
|
Hematoma |
3.7% 3.7% |
de Melo et al (2001) 6 Lodder et al (2015) 7 |
|
Poor osteotomy site healing |
7% |
Nam et al (2006) 9 |
|
Exposed/infected hardware |
3.2% |
Lodder et al (2015) 7 |
|
Osteoradionecrosis of mandible |
5-15% |
Balough et al (1989) 10 |
|
Orocutaneous fistula |
4.2% |
Awad et al (2015) 11 |
|
Chylous fistula |
1.8% |
de Melo et al (2001) 6 |
|
Mortality |
3.6% 1.6% 1% 0.8% |
de Melo et al (2001) 6 Lodder et al (2015) 7 Schwam et al (2015) 8 Awad et al (2015) 11 |
Initiatives such as the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) and the American Academy of Otolaryngology—Head and Neck Surgery’s Reg-ent, clinical data registries, both aim to standardize the frequency and manner in which postoperative complications are reported. Based on the ACS-NSQIP database, an analysis of 408 oral cavity cancer patients, treated between 2005 and 2010, showed the short-term complication rate within 30-days of surgery was 20.3%. 8 No tumor staging information was provided by this database. The most common complications were the need for reoperation (9.6%), infections including pneumonia, urinary tract infections, and sepsis (6.6%), respiratory problems (5.2%), and surgical site infections and/or dehiscence (4.7%). The majority of complications occurred from 2 to 10 days following surgery and, when present, extended the mean length of hospital stay from 3 to 15 days.
Oral cavity resections with complex reconstruction generally have a higher risk of complications. Lodder et al 7 reported complication rates at a single institution following oral cavity composite ablative surgery and free flap reconstruction. For their 184 patients who underwent 189 composite resections and free flaps, the complication rate was 40.2%. The most common surgical complications were flap related (6.9%, 13 patients), wound infection (8.5%, 16 patients), and donor site complications (5.3%, 10 patients). Twenty-one patients (11.1%) required a return to the operating room and corrective surgery.
40.2.2 Causes/Risk Factors
Comorbidities, cancer-related characteristics, and surgical factors all contribute to complications. The presence of comorbidities in the head and neck cancer population are associated with worse survival and complication rates. A prospective study of comorbidities in cancer patients treated at academic teaching hospitals showed that an estimated 21% of head and neck cancer patients had moderate-to-severe comorbidities with the severity associated with poorer overall survival. 12 In a retrospective review of 110 patients with tongue and floor of mouth tumors, Ribiero et al 13 found that survival within each tumor stage could be further stratified by medical comorbidities. Moreover, tobacco and alcohol use, common risk factors for head and neck malignancies, along with malnutrition and diabetes are known to impair wound healing and increase risk of healing-related complications. 8 , 14
Cancer-related risk factors such as advanced staged disease and certain critical tumor locations can result in more extensive and/or impactful surgical resections with more consequential sequelae and rehabilitation needs. Furthermore, patients who require adjuvant radiation or have a history of radiation are more prone to breakdown due to radiation-induced damage to the extracellular matrix, stromal cells, and microvasculature. 15
Surgical risk factors include the extent of surgery such as the inclusion of neck dissections, choice of reconstruction, duration of surgery, time under anesthesia, and presence and extent of prophylactic antibiotics. For example, Schwam et al 8 reported a correlation between the addition of neck dissections and surgical site and infection-related complications. Higher complication rates are generally found in oral cavity cancer patients who undergo resection with free flap surgery as shown above. These cases are also associated with longer anesthesia time and blood transfusions. 7
While disease-related risk factors cannot be modified, patient-related and surgical risk factors can influence the surgical plan and the nature of counseling with patients, given the expectation for certain complications. For example, in an elderly, malnourished patient with cardiac comorbidities, nutritional supplementation can be initiated preoperatively; also, the choice of reconstruction following tumor resection may favor a shorter operative duration. Additional modifiable risk factors will be discussed later in this chapter.
40.3 Clinical Presentation
Many complications overlap in presentation. Pain, swelling, signs of infection, fever, salivary leakage, changes in drain content, neurologic dysfunction, and poorly healing surgical sites can signal the development of a complication. Immediately following surgery, monitoring for hematoma, seroma, signs of infection, and malunion following mandibulotomies or mandibulectomies should be performed. Paresthesias and paresis can indicate nerve injury. Nonhealing surgical incisions or open cutaneous wounds can indicate an oral-cutaneous fistula. Delayed complications such as ORN can present as trismus, exposed bone, bony necrosis, and pain.
Free flap reconstruction carries its own subset of complications. Commonly assessed problems include, but are not limited to, loss of blood flow to the flap (due to thrombosis, vessel compression, or anastomotic leak), reconstruction break down with salivary fistula or functional impairment, donor site infections, donor site sensory or motor nerve injury, and donor site distal ischemia. Monitoring of the free flap may reveal venous congestion in the case of venous thromboses or a pale cool flap in the setting of arterial thromboses. The clinical exam may also include pricking the flap with a needle away from the vascular pedicles during which bright brisk bleeding indicates a healthy flap while dark blood indicates venous congestion. Additional tools to supplement the clinical exam include Doppler probes to measure pulse, implantable Doppler probes placed near the draining vein useful in buried flaps, temperature probes, pulse oximeter probes, and near-infrared spectroscopy. 16 Additional resources highlight these nuances specific to free tissue reconstruction. 17 , 18
40.4 Diagnosis and Evaluation
Most complications can be diagnosed by physical exam. Close assessment of the surgical site and a thorough head and neck exam may reveal erythema, edema, drainage, or dehiscence suggesting reconstruction breakdown or brewing infections. Surgical drains may show fresh blood indicative of a hematoma, pus indicative of an abscess or salivary fistula, saliva or food/drink/tube feeds suggestive of a salivary fistula, or cloudy fluid suggestive of a chylous fistula. Following radiation, patients should be monitored for trismus due to radiation-induced tissue changes and exposed hardware from poorly vascularized tissue. Assessing occlusion, loose teeth, and motion of the temporomandibular joint can help identify malunion, loose hardware, or developing ORN.
Labs, pathology, and imaging support but do not replace clinical findings. Leukocytosis can indicate infection or presence of tumor. A decrease in hemoglobin may signal a hematoma. Fluid from surgical drains can be tested for triglycerides if there is a concern for a chyle leak. In the setting of poor wound healing, labs such as thyroid-stimulating hormone, albumin, and erythrocyte sedimentation rate can be sent to assess for degree of malnutrition. In addition, any surgical sites with concern for infection should be cultured for culture-directed antibiotic treatment.
Biopsy should be considered if there is a concern for recurrence. In cases of advanced disease following surgery, patients may present with what appears as an infection: draining purulent wounds, leukocytosis, and rim-enhancing fluid collections on imaging (▶ Fig. 39.16). While infection is a clear differential diagnosis, persistent or recurrent cancer may also be a differential diagnosis and fine-needle aspiration or open biopsy should be performed.
Imaging bolsters the clinical exam by better assessing deep tissue structures. Computed tomography (CT) with contrast is an important modality to assess for rim-enhancing fluid collections or phlegmon representing infection, possible recurrence, and bone quality signaling ORN or postsurgical fractures. Magnetic resonance imaging (MRI) is valuable following free tissue reconstruction to further delineate soft tissue changes.
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