Transoral robotic surgery and transoral laser microsurgery for oropharyngeal squamous cell cancer

The aim of our study was to compare transoral laser microsurgery (TLM) and transoral robotic surgery (TORS) for primary resection of oropharyngeal squamous cell cancer (OPSCC). This was a retrospective chart analysis of 33 patients with OPSCC treated at one academic medical center with either TORS (n = 17) or TLM (n = 16) between July 2008 and December 2010. Six patients in the TLM group and seven patients in the TORS group had primary cancer of the tonsil; the remaining patients had base of tongue cancer. Two patients in the TORS group had Stage I or II disease; the other 31 patients had Stage III [1/16 (6 %) TLM; 5/17 (29 %) TORS] or Stage IV cancer [15/16 (94 %) TLM; 10/17 (59 %) TORS]. The intervention was transoral surgery for OPSCC, and the main outcome measures were perioperative variables and functional outcomes. Mean operative time was 170 versus 115 min for TLM and TORS, respectively (p = 0.057). One patient, in the TLM group, required a temporary tracheostomy. Perioperative feeding tubes were placed in 6/16 (38 %) patients who underwent TLM and in 4/17 (24 %) patients who underwent TORS (p = 0.465). At a median follow-up of 14.5 months, the average MD Anderson Dysphagia Inventory score was 65.2 for TLM and 70.8 for TORS (p = 0.431). All TORS procedures were performed with a single oral retractor, while multiple laryngoscopes were required in 9/16 (56 %) TLM cases (p = 0.0003). The mean number of total specimens were 6.2 for TORS and 13.6 for TLM (p = 0.002). These results demonstrate that TLM and TORS have comparable perioperative variables with no significant differences in functional outcomes. For a subset of patients, TORS reduced the spatial complexity of surgery, suggested by the decreased need for multiple laryngoscopes, fewer specimens, and shorter operative times, while larger tumors were more amenable to TLM.     

Connective tissue activation

Connective tissue activating peptides from lymphocytes (CTAP-I) and platelets (CTAP-III) are known to stimulate glycosaminoglycan synthesis, glycolysis, and mitogenesis in connective tissue cell cultures. Direct evidence suggested that increased accumulation of cyclic AMP was involved in the action of these peptide agonists, and increased prostaglandin E synthesis was postulated on the basis of indirect evidence. In the present experiments, CTAP-I and -III were incubated with human and murine cells in culture, and prostaglandin E was measured by radioimmunoassay using antibody directed primarily to prostaglandin E2. Both CTAP-I and -III markedly stimulated the elaboration of prostaglandin E into culture medium, the earliest evidence of increased synthesis occurring at 4 hours with maximal concentrations found at 24 hours. Substantial residual stimulation persisted at least through 48 hours. Indo-methacin (13.0 m̈g/ml) obliterated basal and incremental synthesis of prostaglandin in the presence of mediators. Cycloheximide (8.7 m̈g/ml) did not affect the stimulation of prostaglandin synthesis by CTAP-I and -III. Three nonrheumatoid and 3 rheumatoid synovial cell strains showed similar basal levels of prostaglandin E and similar responses to CTAP-I. A murine fibroblast cell strain (3T3) showed increased prostaglandin E synthesis on exposure to CTAP-I, and the KB tumor cell strain was markedly stimulated by CTAP-III. These studies confirm the increased synthesis of E series prostaglandins postulated to occur in human connective tissue cells on exposure to CTAP-I and -III, and clarify the mechanism of action of these agonists on “activated” target cells. The importance of elevated extracellular concentrations of prostaglandins is uncertain, although they may act directly on sensitive cell types as well as potentiate the actions of CTAP-I and -III on neighboring cells.