Transoral robotic surgery: supraglottic laryngectomy in a canine model

OBJECTIVES/HYPOTHESIS: To develop a technique for computer enhanced robotic transoral supraglottic partial laryngectomy in the canine model. STUDY DESIGN: Surgical procedure on the larynx in a canine model with a commercially available surgical robot. METHODS: With use of the da Vinci Surgical Robot (Intuitive Surgical, Inc., Sunnyvale, CA), the supraglottic partial laryngectomy was performed on a mongrel dog that had been orotracheally intubated using general anesthesia. The videoscope and the 8 mm end-effectors of the robotic system were introduced through three ports, transorally. The surgical procedure was performed remotely from the robotic system console. The procedure was documented with still and video photography. RESULTS: Supraglottic partial laryngectomy was successfully performed using the da Vinci Surgical Robot, with 8 mm instrumentation. The robotic system allowed for celerity and accuracy secondary to findings specific to the surgical approach, including excellent hemostasis, superb visualization of the operative field with expeditious identification of laryngeal submucosal soft tissue and skeletal landmarks, and multiplanar transection of tissues. In addition, the use of the robotic system also was found to have technical advantages inherent in robotic surgery, including the use of "wristed" instrumentation, tremor abolition, motion scaling, and three-dimensional vision. CONCLUSIONS: The da Vinci Surgical Robot allowed for successful robotic transoral supraglottic partial laryngectomy in the canine model.     

Bilateral petrous internal carotid artery pseudoaneurysms presenting with sensorineural hearing loss

We present a case of an 85-year-old woman with a 40-year history of progressive bilateral sensorineural hearing loss. Imaging studies demonstrated bilateral pseudoaneurysms of the petrous portion of the internal carotid arteries eroding into both cochleas. To our knowledge, this is the first case report of such lesions.     

ER stress regulates myeloid-derived suppressor cell fate through TRAIL-R–mediated apoptosis

Myeloid-derived suppressor cells (MDSCs) dampen the immune response thorough inhibition of T cell activation and proliferation and often are expanded in pathological conditions. Here, we studied the fate of MDSCs in cancer. Unexpectedly, MDSCs had lower viability and a shorter half-life in tumor-bearing mice compared with neutrophils and monocytes. The reduction of MDSC viability was due to increased apoptosis, which was mediated by increased expression of TNF-related apoptosis–induced ligand receptors (TRAIL-Rs) in these cells. Targeting TRAIL-Rs in naive mice did not affect myeloid cell populations, but it dramatically reduced the presence of MDSCs and improved immune responses in tumor-bearing mice. Treatment of myeloid cells with proinflammatory cytokines did not affect TRAIL-R expression; however, induction of ER stress in myeloid cells recapitulated changes in TRAIL-R expression observed in tumor-bearing hosts. The ER stress response was detected in MDSCs isolated from cancer patients and tumor-bearing mice, but not in control neutrophils or monocytes, and blockade of ER stress abrogated tumor-associated changes in TRAIL-Rs. Together, these data indicate that MDSC pathophysiology is linked to ER stress, which shortens the lifespan of these cells in the periphery and promotes expansion in BM. Furthermore, TRAIL-Rs can be considered as potential targets for selectively inhibiting MDSCs.     

Synthesis and antiviral activity of enantiomeric forms of cyclobutyl nucleoside analogues.

The syntheses of the enantiomeric cyclobutyl guanine nucleoside analogues [1R-1 alpha, 2 beta, 3 alpha]- and [1S-1 alpha, 2 beta, 3 alpha]-2- amino-9-[2,3-bis(hydroxymethyl)cyclobutyl]-6H-purin-6-one (7 and 8, respectively) and the enantiomeric cyclobutyl adenine analogues [1R-1 alpha, 2 beta, 3 alpha]- and [1S-1 alpha, 2 beta, 3 alpha]-6-amino-9-[2,3-bis(hydroxymethyl) cyclobutyl]purine (9 and 10, respectively) are described. trans-3,3-Diethoxy-1,2-cyclobutanedicarboxylic acid (14) was coupled with R-(-)-2-phenylglycinol to provide a mixture of diastereomeric bis-amides, 15a and 15b, which was readily separated by crystallization. Conversion of each bis-amide to the corresponding diol enantiomer, 16a and 16b, respectively, was effected by a facile three-step sequence in high overall yield. Homochiral diol 16a was converted in a straightforward manner to 7 and 9, and homochiral diol 16b was similarly converted to the corresponding optical isomers 8 and 10. Compounds 7 and 9, which mimic the absolute configuration of natural nucleosides, are highly active against a range of herpesviruses in vitro while the isomers of opposite configuration, 8 and 10, are devoid of antiherpes activity. The corresponding triphosphates of 7 and 8 (7-TP and 8-TP) were prepared enzymatically. Compound 7-TP selectively inhibits HSV-1 DNA polymerase, compared to human (HeLa) DNA polymerase, while 8-TP is much less inhibitory than 7-TP against both types of enzymes. Compounds 7 and 9 are efficacious in a mouse cytomegalovirus model infection.     

Assessment of intraoperative safety in transoral robotic surgery

INTRODUCTION: Robotic technology has been safely integrated into thoracic and abdominopelvic surgery, and the early experience has been very promising with very rare complications related to robotic device failure. Recently, several reports have documented the technical feasibility of transoral robotic surgery (TORS) with the daVinci Surgical System. Proposed pharyngeal and laryngeal applications include radical tonsillectomy, base-of-tongue resection, supraglottic laryngectomy, and phonomicrosurgery. The safety of transoral placement of the robotic endoscope and instruments has not been established. Potential risks specific to the transoral use of the surgical robot include facial skin laceration, tooth injury, mucosal laceration, mandible fracture, cervical spine fracture, and ocular injury. We hypothesize that these particular risks of transoral surgery are similar with robotic assistance compared with conventional transoral surgery. METHODS: To test this hypothesis, we attempted to intentionally injure a human cadaver with the daVinci Surgical System by impaling the facial skin and pharyngeal and laryngeal mucosa with the robotic instruments and endoscope. We also attempted to extract or fracture teeth and fracture the cadaver's mandible and cervical spine by applying maximal pressure and torque with the robotic arms. Experiments were documented with still and video photography. RESULTS: Impaling the cadaver's skin and mucosa resulted in only superficial lacerations. Tooth, mandible, and cervical spine fracture could not be achieved. CONCLUSIONS: Initial experiments performing TORS on a human cadaver with the daVinci Surgical System demonstrate a safety profile similar to conventional transoral surgery. Additionally, we discuss several strategies to increase patient safety in TORS.     

Pediatric submandibular triangle masses: a fifteen-year experience

BACKGROUND: The purpose of this study was to evaluate the surgical results of pediatric submandibular triangle masses, with specific attention to neoplastic processes. METHODS: We retrospectively reviewed the medical records of 105 patients aged 6 months to 21 years who underwent surgery in the submandibular triangle at a major pediatric tertiary care hospital from 1987 to 2001. RESULTS: One hundred five patients who underwent surgery in the submandibular triangle were included in the study. Twenty patients had neoplastic processes, six of which were of primary salivary origin (two mucoepidermoid carcinomas and four pleomorphic adenomas). Twenty-four patients underwent excision of inflamed or infected lymph nodes, and 23 patients underwent excision of inflamed or infected submandibular glands. Thirty-eight patients were included who underwent surgery for sialorrhea or to gain access for another surgical procedure. Complications included tumor recurrence, transient and permanent marginal mandibular nerve weakness, ranula, postoperative fluid collection, and cellulitis. Duration of follow-up ranged from no follow-up to 11 years. CONCLUSION: Surgical excision of submandibular triangle masses is uncommon. We present our experience with these lesions, with a discussion of diagnosis, surgical indications, and surgical complications.     

Ovarian Carcinoma Initially Presenting as Metastatic Axillary Lymphadenopathy

Background.Ovarian carcinoma usually presents at advanced stage due to diffuse intraabdominal disease. Presenting signs and symptoms often relate to the degree of intraabdominal spread. It is rare to have distant lymph node metastases, in conjunction with minimal intraabdominal disease, at initial presentation.Case.A 78-year-old woman was noted to have an enlarged axillary lymph node on a routine, screening mammogram. Biopsy revealed metastatic adenocarcinoma, consistent with primary breast cancer. Physical examination, diagnostic mammogram, and magnetic resonance imaging of the breasts were normal. A pelvic computed tomography scan revealed a 7-cm complex, right adnexal mass. At exploratory laparotomy, there was minimal intraabdominal tumor burden; only a 6-cm right ovarian tumor and a single 1.0-cm nodule adherent to the bladder peritoneum were found. After optimal cytoreductive surgery, she received tamoxifen for presumed metastatic breast cancer. One year later, recurrent disease developed in the pelvis. After reexploration and excision of all gross pelvic disease, a revised diagnosis of recurrent ovarian cancer was made, and therapy was changed to carboplatin and paclitaxel chemotherapy. The patient is currently without evidence of disease.Conclusion.Ovarian carcinoma usually presents with signs and symptoms related to the tumor burden within the peritoneal cavity. The finding of isolated, distant metastatic lymphadenopathy with minimal intraabdominal disease is very unusual. Immunohistochemical tumor markers can help determine the origin of a metastatic adenocarcinoma when the clinical presentation is atypical.     

Spontaneous uterine rupture in the early third trimester after laparoscopically assisted myomectomy. A case report

BACKGROUND: The development of new and innovative laparoscopic instruments has allowed a greater number of gynecologic surgeons to laparoscopically remove large, intramural leiomyomata. Cases of both successful pregnancy and uterine rupture following laparoscopic myomectomy have been reported. This is the first report of uterine rupture in pregnancy following a laparoscopically assisted myomectomy. CASE: A 26-year-old, nulligravid woman underwent a laparoscopically assisted myomectomy. While the myomectomy had been performed laparoscopically, the uterine incision had been repaired in layers through a minilaparotomy incision. Two years later she became pregnant and, at 29 weeks' gestation, presented to labor and delivery with contractions and uterine tenderness. Over the next several hours, a nonreassuring fetal heart rate developed, and a cesarean section was performed, revealing hemoperitoneum and uterine rupture at the site of the prior myomectomy. CONCLUSION: The ultimate integrity of a uterine incision may depend not only on how the incision is repaired but also on how it is made. Laparoscopically created uterine incisions may not be as strong as those made at laparotomy, regardless of the method of closure.     

Robotic microlaryngeal surgery: a technical feasibility study using the daVinci surgical robot and an airway mannequin

OBJECTIVES/HYPOTHESIS: The trend toward minimally invasive surgery has led to the development and mastery of endoscopic and laparoscopic surgical techniques. These minimally invasive approaches, which only two decades ago were either novel or experimental, are now mainstream. More recently, robot-assisted surgery has evolved as an adjunct to open and endoscopic techniques. Surgical robots are now approved by the United States Food and Drug Administration for a variety of thoracic and abdominal/pelvic surgical procedures. The purpose of this study is to demonstrate the technical feasibility of robot-assisted microlaryngeal surgery. STUDY DESIGN: Experimental surgical manipulation of the larynx in an airway mannequin with a surgical robot. METHODS: A variety of laryngoscopes and mouthgags, coupled with the daVinci Surgical Robot's (Intuitive Surgical, Sunnyvale, CA) 0-degree and 30-degree, two-dimensional and three-dimensional endoscopes, were utilized to optimize visualization of the larynx in an airway mannequin. Five millimeter and 8 mm microinstruments compatible with the daVinci robot were utilized to manipulate different elements of the larynx. Experiments were recorded with both still and video photography. RESULTS: The endoscope and robotic arms of the daVinci robot are well suited to airway surgery. CONCLUSIONS: Robot-assisted laryngeal surgery can be performed with currently available technology. The potential for fine manipulation of tissues, increased freedom of instrument movement, and endolaryngeal suturing may increase the precision of endoscopic laryngeal microsurgery and offers the potential to increase the variety of laryngeal procedures that can be performed endoscopically.