Impact of neoadjuvant chemoradiation on perioperative outcomes in patients with rectal cancer.

BACKGROUND AND OBJECTIVES: Neoadjuvant chemoradiation for rectal cancer is associated with lower local recurrence rates. The objective of this study is to assess the impact of neoadjuvant therapy on perioperative complications in patients with rectal cancer. METHODS: Using the ACS-NSQIP database (2005-2012), a propensity score was used to match 3592 patients with rectal cancer receiving neoadjuvant therapy to 3592 patients undergoing surgery alone. The association between neoadjuvant chemoradiation and perioperative outcomes was evaluated. RESULTS: Among all patients, overall morbidity was significantly higher in the neoadjuvant therapy group (n = 1170, 29.9%) compared to the surgery alone (n = 2350, 26.4%; P < 0.0001), but 30-day mortality was lower in the neoadjuvant group (n = 27, 0.7%) compared to the surgery alone group (n = 112, 1.3%; P = 0.0043). However, in propensity-matched patients, there was no difference in overall morbidity (OR 0.912, 95% CI 0.825-1.008) or 30-day mortality (OR 0.639, 95% CI 0.38-1.05). Overall morbidity and 30-day mortality were 29.3% (n = 1054) and 0.7% (n = 25) in the neoadjuvant group, respectively, compared to 31.3% (n = 1124) and 1.1% (n = 39) in the surgery alone group, respectively. CONCLUSION: Patients with newly diagnosed rectal cancer could be evaluated for neoadjuvant therapy prior to surgical resection without the fear of upfront therapy causing a significant increase in perioperative complications.

Separating the Laparoscopic Camera Cord From the Monopolar "Bovie" Cord Reduces Unintended Thermal Injury From Antenna Coupling: A Randomized Controlled Trial.

OBJECTIVE(S): The monopolar "Bovie" is used in virtually every laparoscopic operation. The active electrode and its cord emit radiofrequency energy that couples (or transfers) to nearby conductive material without direct contact. This phenomenon is increased when the active electrode cord is oriented parallel to another wire/cord. The parallel orientation of the "Bovie" and laparoscopic camera cords cause transfer of energy to the camera cord resulting in cutaneous burns at the camera trocar incision. We hypothesized that separating the active electrode/camera cords would reduce thermal injury occurring at the camera trocar incision in comparison to parallel oriented active electrode/camera cords. METHODS: In this prospective, blinded, randomized controlled trial, patients undergoing standardized laparoscopic cholecystectomy were randomized to separated active electrode/camera cords or parallel oriented active electrode/camera cords. The primary outcome variable was thermal injury determined by histology from skin biopsied at the camera trocar incision. RESULTS: Eighty-four patients participated. Baseline demographics were similar in the groups for age, sex, preoperative diagnosis, operative time, and blood loss. Thermal injury at the camera trocar incision was lower in the separated versus parallel group (31% vs 57%; P = 0.027). CONCLUSIONS: Separation of the laparoscopic camera cord from the active electrode cord decreases thermal injury from antenna coupling at the camera trocar incision in comparison to the parallel orientation of these cords. Therefore, parallel orientation of these cords (an arrangement promoted by integrated operating rooms) should be abandoned. The findings of this study should influence the operating room setup for all laparoscopic cases.

Surgical Energy-Based Device Injuries and Fatalities Reported to the Food and Drug Administration.

BACKGROUND: Energy-based devices are used in virtually every operation. Our purposes were to describe causes of energy-based device complications leading to injury or death, and to determine if common mechanisms leading to injury or death can be identified. STUDY DESIGN: The FDA's Manufacturer and User Facility Device Experience (MAUDE) database was searched for surgical energy-based device injuries and deaths reported over 20 years (January 1994 to December 2013). Device-related complications were recorded and analyzed. RESULTS: We analyzed 178 deaths and 3,553 injuries. Common patterns of complications were: thermal burns, 63% (n = 2,353); hemorrhage, 17% (n = 642); mechanical failure of device, 12% (n = 442); and fire, 8% (n = 294). Events were identified intraoperatively in 82% (3,056), inpatient postoperatively in 9% (n = 351), and after discharge in 9% (n = 324). Of the deaths, 12% (n = 22) occurred after discharge home. Common mechanisms for thermal burn injuries were: direct application, 30% (n = 694); dispersive electrode burn, 29% (n = 657); and insulation failure, 14% (n = 324). Thermal injury was the most common reason for death (39%, n = 70). The mechanism for these thermal injuries was most frequently direct application (84%, n = 59, p < 0.001 vs all other mechanisms). Fires were most common with monopolar "Bovie" instruments (88%, n = 258, p < 0.001 vs all other devices) when they were used in head and neck operations (66%, n = 193, p < 0.001 vs all other locations). CONCLUSIONS: Complications due to energy-based devices occur from 4 main causes: thermal burn, hemorrhage, mechanical failure, and fire. Thermal direct application injuries are the most common reason for both injury and death.

Postoperative pneumoperitoneum: is it normal or pathologic?

BACKGROUND: Pneumoperitoneum on computed tomography (CT) after abdominal surgery is common, but its incidence, duration, and clinical significance is widely debated. MATERIALS AND METHODS: A retrospective, cohort study of patients who underwent abdominal CT within 30 days of abdominal surgery. RESULTS: Among 344 patients, pneumoperitoneum was found in 39% (135/344) of patients on postoperative days 0-6 in 53%, 7-13 in 41%, 14-20 in 23%, 21-27 in 13%, and 28-30 in 0%. Pneumoperitoneum was associated with the presence of a drain (P = 0.014) but not with age, gender, body mass index, smoking history, lung disease, or open versus laparoscopic surgery (P > 0.05 for all variables). Eight patients required intervention (6%), most commonly for anastomotic leak (4 patients, 50%). CONCLUSIONS: Postoperative pneumoperitoneum on abdominal CT can be seen in up to 23% of patients 3-weeks postoperatively; however, only 6% of the patients required intervention emphasizing the typically benign consequences of postoperative free air.

Effect of radiofrequency energy emitted from monopolar "Bovie" instruments on cardiac implantable electronic devices.

BACKGROUND: The monopolar "Bovie" instrument emits radiofrequency energy that can disrupt the function of other implanted electronic devices through a phenomenon termed electromagnetic interference. The purpose of this study was to quantify the electromagnetic interference occurring on cardiac implantable devices (CIEDs) resulting from monopolar instrument use in common, modifiable clinical scenarios. STUDY DESIGN: Three anesthetized pigs underwent CIED placement (1 pacemaker and 2 defibrillators). Electromagnetic interference was quantified when changing the monopolar instrument parameters of generator power, generator mode, surgical technique, orientation of active electrode cord, pathway of current vector, and proximity of active electrode to the CIED. RESULTS: Monopolar instrument parameters that decreased the electromagnetic interference occurring on the CIED included decreasing generator power from 60 W to 30 W (p < 0.001), using cut mode rather than coag mode (p < 0.001), using desiccation technique rather than fulguration technique (p < 0.001), orienting the active electrode cord from the feet rather than across the chest wall (p < 0.001), and avoiding the current vector from crossing the CIED system (p < 0.001). Increasing the distance between the active electrode tool and the CIED system decreased electromagnetic interference occurring on the CIED in a dose-response fashion up to a distance of 10 cm (ANOVA, p < 0.001), after which the magnitude of electromagnetic interference remained constant. CONCLUSIONS: Electromagnetic interference occurring on CIEDs resulting from monopolar instruments is minimized by decreasing generator power, using cut mode, using desiccation technique, orienting the active electrode cord from the feet, avoiding the current vector for crossing the CIED system, and increasing the distance between the active electrode and the CIED. Surgeons and operating room staff can minimize electromagnetic interference on CIEDs during monopolar instrument use by accounting for these modifiable clinical factors.

Slower walking speed forecasts increased postoperative morbidity and 1-year mortality across surgical specialties.

OBJECTIVE: The purpose of this study was to determine the relationship between the Timed Up and Go test and postoperative morbidity and 1-year mortality, and to compare the Timed Up and Go to the standard-of-care surgical risk calculators for prediction of postoperative complications. METHODS: In this prospective cohort study, patients 65 years and older undergoing elective colorectal and cardiac operations with a minimum of 1-year follow-up were included. The Timed Up and Go test was performed preoperatively. This timed test starts with the subject standing from a chair, walking 10 feet, returning to the chair, and ends after the subject sits. Timed Up and Go results were grouped as fast ≤ 10 seconds, intermediate = 11-14 seconds, and slow ≥ 15 seconds. Receiver operating characteristic curves were used to compare the 3 Timed Up and Go groups to current standard-of-care surgical risk calculators at forecasting postoperative complications. RESULTS: This study included 272 subjects (mean age of 74 ± 6 years). Slower Timed Up and Go was associated with increased postoperative complications after colorectal (fast 13%, intermediate 29%, and slow 77%; P < 0.001) and cardiac (fast 11%, intermediate 26%, and slow 52%; P < 0.001) operations. Slower Timed Up and Go was associated with increased 1-year mortality following both colorectal (fast 3%, intermediate 10%, and slow 31%; P = 0.006) and cardiac (fast 2%, intermediate 3%, and slow 12%; P = 0.039) operations. Receiver operating characteristic area under curve of the Timed Up and Go and the risk calculators for the colorectal group was 0.775 (95% CI: 0.670-0.880) and 0.554 (95% CI: 0.499-0.609), and for the cardiac group was 0.684 (95% CI: 0.603-0.766) and 0.552 (95% CI: 0.477-0.626). CONCLUSIONS: Slower Timed Up and Go forecasted increased postoperative complications and 1-year mortality across surgical specialties. Regardless of operation performed, the Timed Up and Go compared favorably to the more complex risk calculators at forecasting postoperative complications.

Blend mode reduces unintended thermal injury by laparoscopic monopolar instruments: a randomized controlled trial.

BACKGROUND: The purpose of this study was to compare histologic evidence of thermal injury at the epigastric and umbilical incisions after elective laparoscopic cholecystectomy performed using the monopolar "Bovie" instrument set on the higher voltage coag mode versus the lower voltage blend mode. We hypothesized that the higher voltage coag mode would create more unintended thermal tissue injury at the epigastric trocar's incision. METHODS: A prospective blinded randomized controlled trial of patients undergoing elective laparoscopic cholecystectomy was performed. Patients were randomized to have their operation performed with the monopolar instrument set at 30 W on either the coag mode or the blend mode. Immediately at the end of the operation, a biopsy sample of skin was obtained from the lower edge of the epigastric incision (through which the monopolar instrument was inserted) and the umbilical incision (through which the camera/telescope was inserted). The outcomes measured were histologic evidence of thermal injury at the epigastric and umbilical incisions (determined by a blinded pathologist). RESULTS: Forty patients were randomized (20 per group). Baseline demographics in the two groups were similar for age, gender, body mass index, preoperative diagnosis, operative time, and blood loss. Unintentional thermal injury was found at 20 % of epigastric incisions and 35 % of umbilical incisions in the total group. The incidence of thermal injury was higher after operations using the coag mode compared to the blend mode at both the epigastric (35 vs. 5 %; p = 0.044) and umbilical (55 vs. 15 %; p = 0.019) trocar incisions. CONCLUSIONS: Radiofrequency energy from the monopolar Bovie instrument causes unintentional thermal injury to skin adjacent to the epigastric and umbilical trocar incisions. The incidence of thermal injury was reduced by using the lower voltage blend mode compared to the coag mode at both the epigastric and umbilical trocar incisions. REGISTRATION NUMBER: NCT016648060 ( www.clinicaltrials.gov ).

Antenna coupling--a novel mechanism of radiofrequency electrosurgery complication: practical implications.

OBJECTIVES: (1) To determine if antenna coupling occurs in common operating room scenarios. (2) To define modifiable clinical variables that reduce the magnitude of antenna coupling. BACKGROUND: Mechanisms of electrosurgical burns where monitoring devices contact the surgical patient are unclear. Antenna coupling occurs when the "bovie" active electrode (electrically active transmitting antenna) emits energy, which is captured by a nonelectrically active wire (electrically inactive receiving antenna) in close proximity without direct contact. METHODS: Monopolar radiofrequency energy was delivered to a laparoscopic instrument (electrically active transmitting antenna), whereas other nonelectrically active wires (electrically inactive receiving antenna) including electrocardiogram (EKG) lead, nonactive "bovie" pencil, and nerve electrode monitor were placed in proximity. Temperature changes of tissue placed adjacent to the electrically inactive receiving antennae were measured. RESULTS: Nonelectrically active wires (receiving antenna) increase tissue temperature when lying parallel to the active electrode cord: EKG pad 2.4°C ± 1.2°C (P = 0.002), "bovie" pencil tip 90°C ± 9°C (P < 0.001), and nerve electrode monitor 106°C ± 12°C (P < 0.001). Factors that reduced the heat generated by antenna coupling included the following: increasing angulation between transmitting and receiving antennae (parallel = 90°C ± 9°C; 45° angle = 53°C ± 10°C; perpendicular = 35°C ± 11°C; P < .001), increasing separation distance between parallel transmitting and receiving antenna (<1 cm = 90°C ± 9°C; 15 cm = 44°C ± 18°C; 30 cm = 39°C ± 2°C; P < .001); and decreasing generator power setting (15 W = 59°C ± 11°C; 30 W = 90°C ± 9°C; 45 W = 98°C ± 8°C; P < .001). CONCLUSIONS: Antenna coupling occurs in common operating room scenarios. Simple, practical measures by the surgeon, such as orienting the receiving antenna at a greater angle and with greater separation to the active electrode cord, or lowering the generator power setting reduce antenna coupling.

Radiofrequency energy antenna coupling to common laparoscopic instruments: practical implications.

BACKGROUND: Electromagnetic coupling can occur between the monopolar "Bovie" instrument and other laparoscopic instruments without direct contact by a phenomenon termed antenna coupling. The purpose of this study was to determine if, and to what extent, radiofrequency energy couples to other common laparoscopic instruments and to describe practical steps that can minimize the magnitude of antenna coupling. METHODS: In a laparoscopic simulator, monopolar radiofrequency energy was delivered to an L-hook. The tips of standard, nonelectrical laparoscopic instruments (either an unlit 10 mm telescope or a 5 mm grasper) were placed adjacent to bovine liver tissue and were never in contact with the active electrode. Thermal imaging quantified the change in tissue temperature nearest the tip of the telescope or grasper at the end of a 5 s activation of the active electrode. RESULTS: A 5 s activation (30 watts, coagulation mode, 4 cm separation between instruments) increased tissue temperature compared with baseline adjacent to the grasper tip (2.2 ± 2.2 °C; p = 0.013) and telescope tip (38.2 ± 8.0 °C; p < 0.001). The laparoscopic telescope tip increased tissue temperature more than the laparoscopic grasper tip (p < 0.001). Lowering the generator power from 30 to 15 Watts decreased the heat generated at the telescope tip (38.2 ± 8.0 vs. 13.5 ± 7.5 °C; p < 0.001). Complete separation of the camera/light cords and the active electrode cord decreased the heat generated near the telescope tip compared with parallel bundling of the cords (38.2 ± 8.0 vs. 15.7 ± 11.6 °C; p < 0.001). CONCLUSIONS: Commonly used laparoscopic instruments couple monopolar radiofrequency energy without direct contact with the active electrode, a phenomenon that results in heat transfer from a nonelectrically active instrument tip to adjacent tissue. Practical steps to minimize heat transfer resulting from antenna coupling include reducing the monopolar generator power setting and avoiding of parallel bundling of the telescope and active electrode cords.

Effect of monopolar radiofrequency energy on pacemaker function.

BACKGROUND: This study aimed to quantify the clinical parameters of mono- and bipolar instruments that inhibit pacemaker function. The specific aims were to quantify pacer inhibition resulting from the monopolar instrument by altering the generator power setting, the generator mode, the distance between the active electrode and the pacemaker, and the location of the dispersive electrode. METHODS: A transvenous ventricular lead pacemaker overdrive paced the native heart rate of an anesthetized pig. The primary outcome variable was pacer inhibition quantified as the number of beats dropped by the pacemaker during 5 s of monopolar active electrode activation. RESULTS: Lowering the generator power setting from 60 to 30 W decreased the number of dropped paced events (2.3 ± 1.2 vs 1.6 ± 0.8 beats; p = 0.045). At 30 W of power, use of the cut mode decreased the number of dropped paced beats compared with the coagulation mode (0.6 ± 0.5 vs 1.6 ± 0.8; p = 0.015). At 30 W coagulation, firing the active electrode at different distances from the pacemaker generator (3.75, 7.5, 15, and 30 cm) did not change the number of dropped paced beats (p = 0.314, analysis of variance [ANOVA]). The dispersive electrode was placed in four locations (right/left gluteus, right/left shoulder). More paced beats were dropped when the current vector traveled through the pacemaker/leads than when it did not (1.5 ± 1.0 vs 0.2 ± 0.4; p < 0.001). CONCLUSIONS: Clinical parameters that reduce the inhibition of a pacemaker by monopolar instruments include lowering the generator power setting, using cut (vs coagulation) mode, and locating the dispersive electrode so the current vector does not traverse the pacemaker generator or leads.

Residual heat of laparoscopic energy devices: how long must the surgeon wait to touch additional tissue?

BACKGROUND: Energy devices are essential laparoscopic tools. Residual heat is defined as the increased instrument temperature after energy activation is completed. This study aimed to determine the length of time a surgeon needs to wait before touching other tissue using four common laparoscopic energy sources. METHODS: Thermal imaging quantified instrument and tissue temperature ex vivo using monopolar coagulation, argon beam coagulation, ultrasonic dissection, and bipolar tissue fusion devices. To simulate realistic operative usage, each instrument was activated for 5 s four consecutive times with 5 s pauses between fires. Thermal conductivity to bovine liver tissue was measured 2.5, 5, 10, and 20 s after final activation. RESULTS: The maximum increase in instrument tip temperature was 172 ± 63°C for the ultrasonic dissection, 81 ± 18°C for the monopolar coagulation, 46 ± 19°C for the bipolar tissue fusion, and 1 ± 1°C for the argon beam coagulation (P < 0.05 for all comparisons). Touching the instrument tip to tissue at four intervals after the final activation (2.5, 5, 10, and 20 s) found that ultrasonic energy raised the tissue temperature higher (maximum change, 58°C) than the other three energy devices at all four time points (P < 0.05). CONCLUSIONS: Ultrasonic energy instruments have greater residual heat than monopolar electrosurgery, bipolar tissue fusion, and argon beam. The ultrasonic energy instrument tips heated tissue more than 20°C from baseline even 20 s after activation; whereas all the other energy sources raised the tissue temperature less than 20°C by 5 s. These practical findings may alter a surgeon's usage of these common energy devices.

Surgeon-controlled factors that reduce monopolar electrosurgery capacitive coupling during laparoscopy.

PURPOSE: To determine the factors that can be modified by the surgeon to reduce monopolar electrosurgery capacitive coupling during laparoscopy. Specific aims were to determine the capacitive coupling energy using different generator power settings, mode settings (cut vs. coagulation), and surgical techniques (desiccation vs. fulguration vs. open air activation). METHODS: An oscilloscope determined the cumulative energy (Joules) of capacitive coupling occurring using laparoscopic monopolar electrosurgery ex vivo. RESULTS: Higher power settings increased capacitive coupling energy (Joules): 25 Watts (1.1±0.7) versus 50 Watts (2.4±0.5; P<0.05). Coagulation mode created greater capacitive coupling energy (2.2±1.0) in comparison with cut mode (1.1±0.5; P<0.05). Open air activation (3.3±0.6) and fulguration (3.3±1.0) had higher capacitive coupling energy in comparison with desiccation (0.6±0.2; P<0.05). CONCLUSIONS: Surgeons can minimize capacitive coupling energy during laparoscopy by lowering the power setting, using cut mode (instead of coagulation), and using the surgical technique of desiccation (instead of open air activation or fulguration).

Insulation failure in laparoscopic instruments.

BACKGROUND: Electrosurgery is used in virtually every laparoscopic operation. In the early days of laparoscopic surgery, capacitive coupling, associated with hybrid trocars, was thought to be the major cause of laparoscopic electrosurgery injuries. Modern laparoscopy has reduced capacitive coupling, and now insulation failure is thought to be the main cause of electrosurgical complications. The aim of this study was (1) to determine the incidence of insulation failures, (2) to compare the incidence of insulation failure in reusable and disposable instruments, and (3) to determine the location of insulation failures. METHODS: At four major urban hospitals, reusable laparoscopic instruments were checked for insulation failure using a high-voltage porosity detector. Disposable L-hooks were collected following laparoscopic cholecystectomy and similarly evaluated for insulation failure. Instruments were determined to have insulation failure if 2.5 kV crossed the instrument's insulation to create a closed loop circuit. Statistical analysis was performed using Fisher's exact or chi(2) analysis (*denotes significance set at p < 0.05). RESULTS: Two hundred twenty-six laparoscopic instruments were tested (165 reusable). Insulation failure occurred more often in reusable (19%; 31/165) than in disposable instruments (3%; 2/61; *p < 0.01). When reusable sets were evaluated, 71% (12/17) were found to have at least one instrument with insulation failure. Insulation failure incidence in reusable instruments was similar between hospitals that routinely checked for insulation failure (19%; 25/130) and hospitals that do not routinely check for insulation failures (33%; 7/21; p = 0.16). Insulation failure was most common in the distal third of the instruments (54%; 25/46) compared to the middle or proximal third of the instruments (*p < 0.05). CONCLUSION: One in five reusable laparoscopic instruments has insulation failure; a finding that is not altered by whether the hospital routinely checks for insulation defects. Disposable instruments have a lower incidence of insulation failure. The distal third of laparoscopic instruments is the most common site of insulation failure.

Endoscopic approaches to upper gastrointestinal bleeding.

Treatment for most patients with upper gastrointestinal bleeding has shifted from the operating room to the endoscopy suite. Endoscopic treatment has resulted in substantial benefit for patients with bleeding from peptic ulcer. Ulcers associated with high-risk stigmata of recent hemorrhage (SRH) not treated endoscopically have 40 per cent to 100 per cent risk of continued or recurrent bleeding and up to a 35 per cent chance of requiring surgical control of bleeding. Endoscopic therapy has reduced the risk of recurrent bleeding to 10 per cent to 20 per cent and the need for surgery to 5 per cent to 10 per cent. These improvements translate to shorter hospital stays, fewer transfusions, lower costs, and less morbidity. Similar progress has been made for patients bleeding from esophageal varices. Mortality for a first variceal bleed is now approximately 20 per cent as compared with 40 per cent to 60 per cent in past decades. Rebleeding after initially successful endoscopic hemostasis is often best treated by a second attempt at endoscopic control. The decision regarding management of recurrent bleeding should be made at the time initial endoscopic control is achieved. Local factors such as experience of the endoscopic team, availability of interventional radiologists, and individual patient characteristics should guide these decisions. Failures of endoscopic control and patients with massive hemorrhage still require operative intervention.