Transcontinental telesurgical nephrectomy using the da Vinci robot in a porcine model.

OBJECTIVES: Robotic telesurgery has been demonstrated over long distances and offers theoretical benefits to urologic training and the care of patients in remote regions. The multiple arms and three-dimensional vision of the da Vinci robotic system provide a platform conducive to long-distance telementoring and telesurgery. Whereas prior telesurgical efforts have used dedicated lines for information transmission, the public Internet offers a less expensive alternative. It was the intent of this study to test the validity of using the da Vinci system in urologic telesurgery, and to conduct telerobotic nephrectomies using the public Internet. METHODS: We performed four right nephrectomies in porcine models using the da Vinci robotic system. Telementoring and telesurgical approaches were used, with resident surgeons operating a console adjacent to the swine, while attending surgeons simultaneously operated a second console at distances of 1300 and 2400 miles from the operating room. RESULTS: All four procedures and both telementoring and telesurgical models were successful. Round-trip delays from 450 to 900 ms were demonstrated. Blood loss was minimal, and there were no intraoperative complications. CONCLUSIONS: This study represents the first use of the da Vinci Surgical System in urologic telesurgery and the first successful telesurgical nephrectomy in an animal model.

Peritoneal acidosis mediates immunoprotection in laparoscopic surgery.

BACKGROUND: We have shown previously that abdominal insufflation with CO(2) increases serum levels of IL-10 and TNFalpha and increases survival among animals with lipopolysaccharide (LPS)-induced sepsis, even after a laparotomy. We demonstrated previously that the effect of CO(2) is not from changes in systemic pH, although the peritoneum is locally acidotic during abdominal insufflation with CO(2) even when systemic pH is corrected. We hypothesized that acidification of the peritoneum via means other than CO(2) insufflation would produce alterations in the inflammatory response similar to those associated with CO(2) pneumoperitoneum. METHODS: In total, 42 rats were randomized into 7 groups (n = 6): 1) LPS only, 2) anesthesia control, 3) helium pneumoperitoneum, 4) CO(2) pneumoperitoneum, 5) buffered mild acid lavage, 6) buffered strong acid lavage, and 7) buffered strong acid lavage + helium pneumoperitoneum. Animals received anesthesia with vaporized isoflurane (except the LPS-only group) and their respective abdominal treatment (pneumoperitoneum and/or lavage) for 30 min followed immediately by stimulation with systemic LPS (1 mg/kg, IV). Blood was harvested via cardiac puncture 60 min after LPS injection, and serum levels of IL-10 and TNFalpha levels were determined by enzyme-linked immunosorbent assay. RESULTS: Mean peritoneal pH decreased (P < .05) after CO(2) pneumoperitoneum, buffered strong acid lavage, and buffered strong acid lavage + helium pneumoperitoneum, and it decreased (P = .1) after helium pneumoperitoneum alone and buffered mild acid lavage. IL-10 levels were increased (P < .01), and TNFalpha levels decreased (P < .001) among animals with acidic peritoneal cavities compared with animals with pH-normal peritoneal cavities. Decreasing peritoneal pH correlated with both increasing IL-10 levels (r = -.465, P < .01) and decreasing TNFalpha levels (r = 0.448, P < .01). Among animals with peritoneal acidosis, there were no differences in levels of IL-10 or TNFalpha regardless of insufflation status (P > .05 for both cytokines). CONCLUSIONS: Acidification of the peritoneal cavity whether by abdominal insufflation or by peritoneal acid lavage increases serum IL-10 and decreases serum TNFalpha levels in response to systemic LPS challenge. The degree of peritoneal acidification correlates with the degree of inflammatory response reduction. These results support the hypothesis that pneumoperitoneum-mediated attenuation of the inflammatory response after laparoscopic surgery occurs via a mechanism of peritoneal cell acidification.

Mentoring console improves collaboration and teaching in surgical robotics.

BACKGROUND: One of the most significant limitations of surgical robots has been their inability to allow multiple surgeons and surgeons-in-training to engage in collaborative control of robotic surgical instruments. We report the initial experience with a novel two-headed da Vinci surgical robot that has two collaborative modes: the "swap" mode allows two surgeons to simultaneously operate and actively swap control of the robot's four arms, and the "nudge" mode allows them to share control of two of the robot's arms. MATERIALS AND METHODS: The utility of the mentoring console operating in its two collaborative modes was evaluated through a combination of dry laboratory exercises and animal laboratory surgery. The results from surgeon-resident collaborative performance of complex three-handed surgical tasks were compared to results from single-surgeon and single-resident performance. Statistical significance was determined using Student's t-test. RESULTS: Collaborative surgeon-resident swap control reduced the time to completion of complex three-handed surgical tasks by 25% compared to single-surgeon operation of a four-armed da Vinci (P < 0.01) and by 34% compared to single-resident operation (P < 0.001). While swap mode was found to be most helpful during parts of surgical procedures that require multiple hands (such as isolation and division of vessels), nudge mode was particularly useful for guiding a resident's hands during crucially precise steps of an operation (such as proper placement of stitches). CONCLUSION: The da Vinci mentoring console greatly facilitates surgeon collaboration during robotic surgery and improves the performance of complex surgical tasks. The mentoring console has the potential to improve resident participation in surgical robotics cases, enhance resident education in surgical training programs engaged in surgical robotics, and improve patient safety during robotic surgery.

General anesthesia delays the inflammatory response and increases survival for mice with endotoxic shock.

Anesthesia is an indispensable component of any operative procedure. In this study, we demonstrate that continuous isoflurane anesthesia for 1 h after a lethal dose (20 mg/kg of body weight) of Escherichia coli lipopolysaccharide (LPS) results in a significant increase in survival of C57BL/6J (B6) mice in comparison with survival of nonanesthetized mice. Protection by anesthesia correlates with a delay in plasma LPS circulation, resulting in a delayed inflammatory response, particularly DNA binding activity of NF-kappaB and serum levels of tumor necrosis factor alpha, interleukin-6 (IL-6), and IL-10. Disparate classes of anesthetic agents produce the same effects on the inflammatory response, which is also independent of the inbred mouse strain used. These results suggest that anesthesia has an important impact on the outcome from endotoxemia. Moreover, the immunomodulatory effects of anesthetics should be considered when interpreting data from experimental animal models.

CO2 abdominal insufflation pretreatment increases survival after a lipopolysaccharide-contaminated laparotomy.

Carbon dioxide (CO(2))-pneumoperitoneum is known to favorably modify the systemic immune response during laparoscopic surgery. The presented studies were designed to determine whether treating animals with CO(2) abdominal insufflation before undergoing a lipopolysaccharide (LPS)-contaminated laparotomy would serve as "shock prophylaxis" and thus improve survival and attenuate cytokine production. Rats were randomized into five groups: CO(2)-pneumoperitoneum, helium-pneumoperitoneum, anesthesia control, laparotomy/LPS control, and LPS only control. Animals in the first four groups all received a laparotomy and a lethal dose of LPS. Immediately preceding their laparotomy, animals in the pneumoperitoneum groups received a 30-minute pretreatment of abdominal insufflation with either CO(2) or helium. The anesthesia control group received a 30-minute pretreatment of isoflurane. Animal mortality was then recorded during the ensuing 72 hours. Subsequently, a similar protocol was repeated for measurements of cytokines. CO(2)-pneumoperitoneum increased survival at 48 hours compared with LPS control (P <.05), and decreased interleukin-6 plasma levels at 2 hours (P <.05). Abdominal insufflation with CO(2) before the performance of a laparotomy contaminated with endotoxin increases survival and attenuates interleukin-6. The beneficial immune-modulating effects of CO(2)-pneumoperitoneum endure after abdominal insufflation. CO(2)-pneumoperitoneum pretreatment may improve outcomes among patients undergoing gastrointestinal surgery who are at high risk for abdominal fecal contamination.

Abdominal insufflation with CO2 causes peritoneal acidosis independent of systemic pH.

We have shown that the inflammation-attenuating effects of CO(2) pneumoperitoneum during laparoscopy are not due to changes in systemic pH. However, acidification of peritoneal macrophages in an in vitro CO(2) environment has been shown to reduce LPS-mediated cytokine release. We tested the hypothesis that the peritoneum is locally acidotic during abdominal insufflation with CO(2)--even when systemic pH is corrected. Rats (n = 20) were anesthetized and randomized into two groups: continued spontaneous ventilation (SV) or intubation and mechanical ventilation (MV). All animals were then subjected to abdominal insufflation with CO(2). Mean arterial pH among SV rats decreased significantly from baseline after 15 and 30 minutes of CO(2) pneumoperitoneum (7.329 --> 7.210 --> 7.191, P < 0.05), while arterial pH among MV rats remained relatively constant (7.388 --> 7.245 --> 7.316, P = NS). In contrast, peritoneal pH dropped significantly from baseline and remained low for both groups during CO(2) abdominal insufflation (SV 6.74 --> 6.41 --> 6.40, P < 0.05; MV 6.94 --> 6.45 --> 6.45, P < 0.05). In a second experiment, rats (n = 10) were randomized to receive abdominal insufflation with either CO(2) or helium. Abdominal insufflation with helium did not significantly affect peritoneal pH (7.10 --> 7.02 --> 6.95, P = NS), and the decrease in pH among CO(2)-insufflated animals was significant compared with helium-insufflated animals (P < 0.05). Peritoneal pH returned to baseline levels in all groups within 15 minutes of desufflation in both experiments. A significant local peritoneal acidosis occurs during laparoscopy which is specifically attributable to the use of CO(2) and which is independent of systemic pH. These data provide additional evidence that localized peritoneal acidosis is central to the mechanism of CO(2)-mediated attenuation of the inflammatory response following laparoscopic surgery.

Anesthesia-specific protection from endotoxic shock is not mediated through the vagus nerve.

BACKGROUND: We have shown recently that volatile anesthetics significantly decrease inflammatory cytokine production and dramatically increase survival among rodents challenged with lipopolysaccharide (LPS). Because acetylcholine's interaction with nicotine receptors on tissue macrophages during vagus nerve stimulation has been implicated in the modulation of LPS-stimulated tumor necrosis factor alpha (TNF-alpha) production, we hypothesized that the mechanism of anesthetic immunoprotection is mediated through the vagus nerve. METHODS: Male Sprague-Dawley rats underwent bilateral cervical vagotomy (n = 20) or sham operation (n = 6). Twenty-four hours postoperatively, vagotomized rats were randomized into 3 groups: LPS injection (V+LPS, n = 6), LPS injection followed by 60 minutes of isoflurane anesthesia (V+LPS+ISO, n = 7), or saline injection (V+S, n = 7). Sham animals were also given LPS (Sham+LPS). A sublethal dose of LPS (8 mg/kg) was used. Blood samples were collected via cardiac puncture 90 minutes after LPS or saline injection, and plasma was isolated for the measurement of cytokines by enzyme-linked immunosorbent assay. Statistical differences between groups were detected by 1-way analysis of variance. RESULTS: Serum TNF-alpha was reduced significantly and interleukin (IL)-6 was abrogated completely among V+LPS+ISO rats, compared with both V+LPS and Sham+LPS animals (P < or = .05 for all). In contrast, levels of the anti-inflammatory cytokine IL-10 were similar among all LPS groups. CONCLUSIONS: Isoflurane anesthesia administered simultaneously with the injection of LPS decreases serum production of TNF-alpha and IL-6 despite bilateral transection of the vagus nerve. Isoflurane-mediated attenuation of proinflammatory cytokine production occurs via a mechanism other than modulation of vagal output.

Laparoscopic total abdominal colectomy in the acute setting.

We report results from a single surgeon's 10-year team experience with laparoscopic total abdominal colectomy. We review our series, which includes a large subgroup of ill, high-risk patients with acute colitis requiring urgent surgery. From 1993 to 2003, we performed 65 laparoscopic total abdominal colectomies. All patients referred for total abdominal colectomy were offered the laparoscopic approach. We prospectively collected the following data on all patients: demographics, surgical indications, preoperative status, duration of surgery, intraoperative blood loss, operative complications, length of stay, subsequent operations, patient satisfaction, and lessons learned from our team experience. Preoperative diagnoses included ulcerative colitis (n=55), Crohn's colitis (n=3), colonic inertia (n=4), and familial adenomatous polyposis (n=3). Among the patients with inflammatory bowel disease, 70% of cases were performed on ill patients, refractory to medical management, requiring urgent surgery. This subgroup was managed with laparoscopic total abdominal colectomy and Brooke ileostomy, with ileoanal pouch anastomosis deferred. Operative times were long, ranging from 6 to 11 hours. Mean intraoperative blood loss was 200 ml. Mean length of stay was 4.3 days and ranged from 2 to 13 days. There were no conversions to open surgery and there were no deaths. Complications occurred in 12% of patients and included intra-abdominal abscess (n=2), wound infection (n=3), stoma stenosis (n=1), and incisional hernia (n=2). Postoperative patient satisfaction was high. Subsequent operations, including restorative proctectomy, were also performed laparoscopically. Laparoscopic total abdominal colectomy is technically challenging and requires a team approach but offers patients significant benefit in length of stay and surgical recovery. This operation can be effectively used with minimal morbidity in difficult, ill patients requiring urgent surgery.

Carbon dioxide pneumoperitoneum-mediated attenuation of the inflammatory response is independent of systemic acidosis.

BACKGROUND: The purpose of this study was to determine if systemic acidosis induced by peritoneal absorption of carbon dioxide (CO2 ) during laparoscopy plays a role in CO2 pneumoperitoneum-mediated attenuation of the acute phase inflammatory response associated with perioperative sepsis. The influence of hepatic polymorphonuclear (PMN) leukocyte infiltration on this phenomenon was also investigated. METHODS: Forty-five rats were randomized into 5 groups: anesthesia control, open cecal ligation and puncture (OCLP), laparoscopic cecal ligation and puncture using helium for insufflation (He LCLP), LCLP using CO2 with continued spontaneous ventilation (LCLP-SV), and LCLP using CO2 with intubation and positive pressure ventilation (LCLP-PPV). RESULTS: After 30 minutes, arterial blood gas parameters remained normal in control, OCLP rats, and He LCLP rats, while CO2 LCLP-SV rats developed significant hypercarbic acidosis. This acidosis was corrected in CO2 LCLP-PPV rats ( P < .0001 vs CO2 LCLP-SV for both). Expression of the rat acute phase gene alpha 2 -macroglobulin was greater after OCLP and He LCLP than after either CO2 LCLP-SV or CO2 LCLP-PPV ( P < .0001 vs either CO2 OCLP-SV for both). However, levels of alpha 2 -macroglobulin were not significantly different between the acidotic (LCLP-SV) and normocarbic (LCLP-PPV) CO2 groups. Infiltration of the hepatic parenchyma by PMNs did not differ significantly between groups. CONCLUSIONS: CO2 insufflation-induced systemic acidosis is not responsible for the reduction in the acute phase inflammatory response observed in laparoscopic animal models of sepsis. Hepatic PMN infiltration also does not appear to mediate this effect.

Videoendoscopic endotracheal intubation in the rat: a comprehensive rodent model of laparoscopic surgery.

BACKGROUND: Peritoneal absorption of CO(2) during abdominal insufflation in laparoscopy may disrupt the acid-base equilibrium and alter the physiological response to stress. Current nonventilated rodent models of laparoscopy do not manage the CO(2) load of pneumoperitoneum, but ventilated surgical rodent models are invasive (tracheotomy) and may independently induce the inflammatory response. MATERIALS AND METHODS: A comprehensive rodent model of laparoscopy was developed. Rats were randomized to receive anesthesia alone, anesthesia plus CO(2) pneumoperitoneum, or anesthesia plus CO(2) pneumoperitoneum with videoendoscopic intubation and mechanical ventilation. Arterial blood-gas analysis was performed at baseline and after 30 min of intervention. RESULTS: Baseline pH, pCO(2), and HCO(3)(-) arterial blood gas parameters were normal for all rats. After 30 min, pCO(2) and pH changed slightly but remained normal among rats receiving anesthesia alone (pCO(2) = 46.5 +/- 1.9; pH = 7.365 +/- 0.009) whereas animals receiving anesthesia plus CO(2) pneumoperitoneum that were dependent on spontaneous respiration for ventilation developed significant hypercarbic acidosis (pCO(2) = 53.2 +/- 1.9, P < 0.05; pH = 7.299 +/- 0.011, P < 0.001). This acidosis was completely corrected with increased minute ventilation in intubated rats receiving mechanical ventilation (pCO(2) = 36.8 +/- 1.5, P < 0.001; pH = 7.398 +/- 0.011, P < 0.001). CONCLUSIONS: CO(2) pneumoperitoneum induces significant hypercarbic acidosis in nonventilated rats. Noninvasive endotracheal intubation is feasible in the rat with videoendoscopic assistance. Our noninvasive rodent model of laparoscopic surgery controls for anesthesia- and capnoperitoneum-related acid-base changes and provides an environment in which the biological response to pneumoperitoneum can be studied precisely.

Robotic abdominal surgery.

As a whole, abdominal surgeons possess excellent videoendoscopic surgical skills. However, the limitations of laparoscopy-such as reduced range of motion and instrument dexterity and 2-dimensional view of the operative field-have inspired even the most accomplished laparoscopists to investigate the potential of surgical robotics to broaden their application of the minimally invasive surgery paradigm. This review discusses data obtained from articles indexed in the MEDLINE database written in English and mapped to the following key words: "surgical robotics," "robotic surgery," "robotics," "computer-assisted surgery," "da Vinci," "Zeus," "fundoplication," "morbid obesity," "hepatectomy," "pancreatectomy," "small intestine," "splenectomy," "colectomy," "adrenalectomy," and "pediatric surgery." A limited subset of 387 publications was reviewed to determine article relevance to abdominal robotic surgery. Particular emphasis was placed on reports that limited their discussion to human applications and surgical outcomes. Included are comments about the initial 202 robotic abdominal surgery cases performed at Johns Hopkins University Hospital (Baltimore, MD) from August 2000 to January 2004. Surgical robotic systems are being used to apply laparoscopy to the surgical treatment of diseases in virtually every abdominal organ. Procedures demanding superior visualization or requiring complex reconstruction necessitating extensive suturing obtain the greatest benefit from robotics over conventional laparoscopy. Whereas advanced surgical robotic systems offer the promise of a unique combination of advantages over open and conventional laparoscopic approaches, clinical data demonstrating improved outcomes are lacking for robotic surgical applications within the abdomen. Outcomes data for surgical robotics are essential given the exorbitant costs associated with the use of these tools.

Twenty-first century surgery using twenty-first century technology: surgical robotics.

INTRODUCTION: The "Nintendo" surgery revolution, which began in 1987, has impacted every surgical specialty. However, our operating rooms remain isolated worlds where surgeons use awkward, primitive, rigid instruments with suboptimal visualization. We need "smart instruments," "smart technology," and "smart imaging." Is surgical robotics the answer? METHODS: We provide an analysis of current surgical technology and skills, propose criteria for what the next generation of surgical instruments and technology should achieve, and then examine the evolution and current state of surgical robotic solutions, assessing how they answer future surgical needs. Finally we report on the U.S. Military's early experience with surgical robotics and the lessons learned therein. RESULTS: Current surgical robotic technology has made remarkable progress with miniaturization, articulating hand-imitating instruments, precision, scaling, and three-dimensional vision. The specialty-specific early clinical applications reviewed are promising, but they do have limitations. Surgical robotics offers enormous military application potential. Needed future refinements are identified, including haptics, communications, infrastructure, and information integration. CONCLUSIONS: Laparoscopic surgery is a transition technology, constrained by instrument, equipment, and skill limitations. Surgical robotics or, more properly, computer-assisted surgery may be the key to the future. The operating room of the future will be an integrated environment with global reach. Surgeons will operate with three-dimensional vision, use real-time three-dimensional reconstructions of patient anatomy, use miniaturized minimally invasive robotic technology, and be able to telementor, teleconsult, and even telemanipulate at a distance, thus offering enhanced patient care and safety.

New tools for laparoscopic division of the pancreas: a comparative animal study.

We tested the hypothesis that the pancreas can be safely divided laparoscopically using non-suture devices. Twelve pigs were randomized into 4 groups: 1) laparoscopic distal pancreatectomy (LDP) using an ultrasonic scalpel; 2) LDP using an ultrasonic scalpel with pancreatic stump suture reinforcement; 3) LDP using a 35-mm laparoscopic linear vascular stapler; 4) LDP using a prototype 35-mm radio-frequency laparoscopic linear vascular stapler. There were no serious complications related to distal pancreatectomy. All groups gained weight by postoperative day (POD) 14. Serum amylase, glucose, electrolytes and total bilirubin levels were measured preoperatively and on POD 1, 3, 7, and 14, and peripancreatic peritoneal fluid amylase levels were measured on POD 7 and 14; all remained normal in all groups. Fewer adhesions to the pancreatic stump were found in the ultrasonic scalpel groups as compared with the stapler groups. Ultrasonic dissection may be the superior means oflaparoscopic transection of the pancreas.

Multiservice laparoscopic surgical training using the daVinci surgical system.

BACKGROUND: The daVinci surgical system affords surgeons a magnified three-dimensional videoscopic view of the operative field and precise articulating laparoscopic instruments. The learning curve for this advanced surgical robotics system is poorly characterized. METHODS: Twenty-three surgeons representing seven surgical subspecialties participated in a surgical robotics training program consisting of standardized daVinci system training (phase 1) followed by self-guided learning in a porcine model (phase 2). RESULTS: The average number of recorded procedures performed per surgeon during phase 2 was 5.5. The mean daVinci system set-up time was 45 minutes and decreased by an average of 56.1% by the third successive set-up (r = -0.702, P <0.005). Operative times decreased 39.0% by the third successive practice operation (r = -0.860, P <0.0005). CONCLUSIONS: New use of the daVinci robot is associated with a rapid learning curve and preclinical animal model training is effective in developing surgical robotics skills.

CO2 Pneumoperitoneum modifies the inflammatory response to sepsis.

OBJECTIVE: To analyze the effect of CO2 pneumoperitoneum on the inflammatory response induced by sepsis during laparoscopy. SUMMARY BACKGROUND DATA: A growing body of evidence challenges the once generally accepted notion that smaller incisions alone account for the observed benefits of the laparoscopic approach. Furthermore, laparoscopic surgery is now being applied to a broad spectrum of patients, including those in whom the inflammatory response is ignited. Delineation of the effects of CO2 pneumoperitoneum on the inflammatory response induced by sepsis is needed. METHODS: Sepsis was induced in rats by cecal ligation and puncture (CLP) performed either open or laparoscopically using CO2 or helium as insufflation gases. Animals were killed 24 hours postoperatively, at which time whole blood was collected for complete blood cell counts and livers were harvested for analysis of hepatic expression of the rat acute phase genes alpha2-macroglobulin and beta-fibrinogen. RESULTS: Laparoscopic CLP using CO2 resulted in significantly reduced hepatic expression of the rat acute phase gene alpha2-macroglobulin compared to both laparoscopic CLP using helium and open CLP. Hepatic expression of another rat acute phase gene, beta-fibrinogen, paralleled that of alpha2-macroglobulin and was significantly reduced following laparoscopic CLP using CO2 compared to laparoscopic CLP using helium. Total white blood cell and neutrophil counts following CLP were both significantly higher when CLP was performed laparoscopically using CO2 than when CLP was performed open or laparoscopically using helium. CONCLUSIONS: Intra-abdominal CO2 present during laparoscopy attenuates the acute phase inflammatory response associated with perioperative sepsis.