Complications of laparoscopy

Cardiovascular collapse during laparoscopy: a brief overview

This review article considers the physiology, differential diagnosis and immediate management of vasovagal response, vascular injury and carbon dioxide embolism caused during the creation of the laparoscopic pneumoperitoneum. These pathologies account for over half of all laparoscopic complications and therefore, by taking a systematic approach to these possibly life-threatening events, laparoscopy can become even safer.

Conjunctival congestion after laparoscopic operation in children: A retrospective case series in a single-centre children's medical centre

Objective

In the present study, we report a retrospective analysis of 23 cases of conjunctival congestion after laparoscopic operation in children and try to explore the causes and intervention measures.

Methods and Results

This is a retrospective, single-centre and observational study, and all patients with conjunctival congestion after laparoscopic operation admitted to our institution between August 2021 and December 2021 were included in this study. Records of 23 patients including 16 male patients and 7 female patients were retrospectively analysed. These patients were in the age group of 2-12 years. Their primary symptom was different degrees of conjunctival congestion, and the symptom onset was between 2 and 7 days after laparoscopic operation, including laparoscopic inguinal hernia repair, laparoscopic appendectomies, laparoscopic Meckel's diverticulectomy, laparoscopic removal of foreign body ingestions and laparoscopic choledochal cystectomy, and the duration of operations varies from 20 min to 255 min. The symptom disappeared from 5 to 21 days after the operation, and the duration of the symptom ranged from 2 to 14 days. A total of 1718 operations were performed, of which 461 were laparoscopic and 1257 were general operations, the incidence of conjunctival congestion after laparoscopic surgery was 23/461, and compared with 0/1257 after ordinary surgery, there was a significant difference between them. Of these 23 patients, 5 patients received no treatment and the other 18 patients were intervened with steroid-containing eye drops. Although eye drops containing steroids can significantly relieve eye discomfort, the duration of conjunctival congestion between the two groups (i.e. steroid-containing eye drop treated vs. non-steroid-containing eye drop treated) did not differ significantly. All patients recovered well. In the follow-up till the end of February 2022, no serious complications had occurred.

Conclusion

Conjunctival congestion after laparoscopic operation is extremely rare in children, and the underlying causes are still unclear. We speculate that the pressure of pneumoperitoneum may be the main cause of this phenomenon. Symptoms may be self-limiting, and steroid-containing eye drops can relieve effectively the discomfort.

Two-port access for laparoscopic surgery for endometrial cancer using conventional laparoscopic instruments

Minimally invasive surgery is the first-line management for endometrial cancer. The role of 2-port access laparoscopy (TPA) has been underestimated. Compared to conventional laparoscopic surgery (CL), TPA is associated with smaller total incision size and less postoperative pain. Compared to single-incision laparoscopic surgery, no specific instruments and surgical techniques are needed. This study primarily evaluated the surgical and pathologic outcomes of TPA with conventional instruments, and additionally evaluated the surgeon’s learning curve. Consecutive patients who underwent TPA and CL for endometrial cancer between 2015 and 2019 were included. Baseline characteristics were recorded. In total, 148 patients (TPA, 89; CL, 59) were identified. The baseline characteristics were similar, except for a greater proportion of patients in the CL group receiving para-aortic lymph node dissection (5.62% vs. 35.59%, P < 0.01). The mean operation time was significantly less in the TPA group (152.09 vs. 187.15 min; P < 0.01). Both the groups had comparable 5-year progression-free survival (TPA, 86.68%) and 5-year overall survival rates (TPA, 93.24%). Analysis of the learning curve showed that the operation time decreased after 3–4 procedures. TPA using conventional laparoscopic instruments for endometrial cancer is feasible and is easily accessible to patients and surgeons.

Perioperative breathing training to prevent postoperative pulmonary complications in patients undergoing laparoscopic colorectal surgery: A randomized controlled trial

OBJECTIVE

The aim of this study was to determine whether perioperative breathing training reduces the incidence of postoperative pulmonary complications in patients undergoing laparoscopic colorectal surgery.

DESIGN

A randomized controlled trial.

SETTING

University hospital.

SUBJECTS

A total of 240 patients undergoing laparoscopic colorectal surgery participated in this study.

INTERVENTION

The enrolled patients were randomized into an intervention or control group. Patients in the intervention group received perioperative breathing training, including deep breathing and coughing exercise, balloon-blowing exercise, and pursed lip breathing exercise. The control group received standard perioperative care without any breathing training.

MAIN MEASURES

The primary endpoint was the incidence of postoperative pulmonary complications. The secondary objectives were to evaluate the effect of perioperative breathing training on arterial oxygenation, incidence of other postoperative complications, patient satisfaction, length of stay, and hospital charges.

RESULTS

The incidence of postoperative pulmonary complications in the breathing training group was lower than that in the control group (5/120 [4%] vs 14/120 [12%]; RR 0.357, 95%CI 0.133-0.960; P = 0.031). In addition, PaO₂ and arterial oxygenation index on the first and fourth days after surgery were significantly higher in the breathing training group than in the control group (P < 0.001). In addition, patients with breathing training had shorter length of stay (6d [IQR 5-7] vs 8d [IQR 7-9]), lower hospital charges (7761 ± 1679 vs 8212 ± 1326), and higher patient satisfaction (9.46 ± 0.65 vs 9.21 ± 0.47) than those without.

CONCLUSION

Perioperative breathing training may reduce the incidence of postoperative pulmonary complications and preserve of arterial oxygenation after laparoscopic colorectal surgery.

Internal Carotid Artery Blood Flow Response to Anesthesia, Pneumoperitoneum, and Head-up Tilt during Laparoscopic Cholecystectomy

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Little is known about how implementation of pneumoperitoneum and head-up tilt position contributes to general anesthesia-induced decrease in cerebral blood flow in humans. We investigated this question in patients undergoing laparoscopic cholecystectomy, hypothesizing that cardiorespiratory changes during this procedure would reduce cerebral perfusion.

Methods

In a nonrandomized, observational study of 16 patients (American Society of Anesthesiologists physical status I or II) undergoing laparoscopic cholecystectomy, internal carotid artery blood velocity was measured by Doppler ultrasound at four time points: awake, after anesthesia induction, after induction of pneumoperitoneum, and after head-up tilt. Vessel diameter was obtained each time, and internal carotid artery blood flow, the main outcome variable, was calculated. The authors recorded pulse contour estimated mean arterial blood pressure (MAP), heart rate (HR), stroke volume (SV) index, cardiac index, end-tidal carbon dioxide (ETco2), bispectral index, and ventilator settings. Results are medians (95% CI).

Results

Internal carotid artery blood flow decreased upon anesthesia induction from 350 ml/min (273 to 410) to 213 ml/min (175 to 249; −37%, P &lt; 0.001), and tended to decrease further with pneumoperitoneum (178 ml/min [127 to 208], −15%, P = 0.026). Tilt induced no further change (171 ml/min [134 to 205]). ETco2 and bispectral index were unchanged after induction. MAP decreased with anesthesia, from 102 (91 to 108) to 72 (65 to 76) mmHg, and then remained unchanged (Pneumoperitoneum: 70 [63 to 75]; Tilt: 74 [66 to 78]). Cardiac index decreased with anesthesia and with pneumoperitoneum (overall from 3.2 [2.7 to 3.5] to 2.3 [1.9 to 2.5] l · min−1 · m−2); tilt induced no further change (2.1 [1.8 to 2.3]). Multiple regression analysis attributed the fall in internal carotid artery blood flow to reduced cardiac index (both HR and SV index contributing) and MAP (P &lt; 0.001). Vessel diameter also declined (P &lt; 0.01).

Conclusions

During laparoscopic cholecystectomy, internal carotid artery blood flow declined with anesthesia and with pneumoperitoneum, in close association with reductions in cardiac index and MAP. Head-up tilt caused no further reduction. Cardiac output independently affects human cerebral blood flow.

Standing Hand-Assisted Laparoscopic Diagnosis and Treatment of a Rare Case of Uterine Adenocarcinoma in an 18-Year-Old Mare

An 18-year-old French Trotter mare was presented to the Clinique Equine, Ecole Nationale Vétérinaire d'Alfort, for exploration of a 3-month-duration vaginal bleeding. A transrectal ultrasound examination identified a mass within the right uterine horn wall, which had been suspected during transrectal palpation. It was described as a firm heterogeneous intramural mass (7 × 12 cm) in the right uterine horn, located few centimeters cranially to the bifurcation. Hysteroscopy confirmed the ulcerated and irregular shape of the mass. A standing hand-assisted flank laparoscopy was performed to carry out a partial ovariohysterectomy. Two days after surgery, the mare presented with acute and severe signs of colic and was euthanized. Postmortem examination revealed a 720° small intestine volvulus at the mesenteric root, a left dorsal displacement of the large colon, and iliac and tracheobronchial lymph node hypertrophy. Histopathological examination of the removed uterine mass revealed a well-differentiated and infiltrating uterine adenocarcinoma, with lymph node metastasis. Uterine neoplasia, especially adenocarcinoma, is uncommon in the mare and can be successfully removed using a standing hand-assisted laparoscopic technique, which avoids the risks associated with general anesthesia and allows a histologic diagnosis of malignancy. In such cases, though, initial staging and identification of metastasis remain a challenge that will influence the treatment strategy.

Value of preoperative spirometry test in predicting postoperative pulmonary complications in high-risk patients after laparoscopic abdominal surgery

Whether preoperative spirometry in non-thoracic surgery can predict postoperative pulmonary complications (PPCs) is controversial. We investigated whether preoperative spirometry results can predict the occurrence of PPCs in patients who had undergone laparoscopic abdominal surgery. This retrospective observational study analyzed the records of patients who underwent inpatient laparoscopic gastric or colorectal cancer surgery at Seoul National University Bundang Hospital between January 2010 and June 2017. Preoperative spirometry was performed for patients at a high risk of PPCs, such as elderly patients (age >60 years), patients aged <60 years with chronic pulmonary disease, and current smokers. The main outcome was the association between the results of spirometry tests performed within 1 month prior to surgery and the occurrence of PPCs, as determined by multivariable logistic regression analysis. Of the 898 included patients who underwent laparoscopic gastric (372 patients) or colorectal cancer surgery (526 patients), PPC occurred in 117 patients (gastric cancer: 74, colorectal cancer: 43). A 1% greater preoperative forced vital capacity (FVC) was associated with a 2% lower incidence of PPCs after laparoscopic gastric or colorectal cancer surgery (odds ratio: 0.98, 95% confidence interval: 0.97–0.99, P = 0.018). However, the preoperative forced expiratory volume in 1 second (FEV1) (%) and FEV1/FVC (%) were not significantly associated with PPCs (P = 0.059 and P = 0.147, respectively). In conclusion, lower preoperative spirometry FVC, but not FEV1 or FEV1/FVC, may predict PPCs in high-risk patients undergoing laparoscopic abdominal surgery.

Intravenous lidocaine for effective pain relief after a laparoscopic colectomy: a prospective, randomized, double-blind, placebo-controlled study

A perioperative intravenous lidocaine infusion has been reported to decrease postoperative pain. The goal of this study was to evaluate the effectiveness of intravenous lidocaine in reducing postoperative pain for laparoscopic colectomy patients. Fifty-five patients scheduled for an elective laparoscopic colectomy were randomly assigned to 2 groups. Group L received an intravenous bolus injection of lidocaine 1.5 mg/kg before intubation, followed by 2 mg/kg/h continuous infusion during the operation. Group C received the same dosage of saline at the same time. Postoperative pain was assessed at 2, 4, 8, 12, 24, and 48 hours after surgery by using the visual analog scale (VAS). Fentanyl consumption by patient-controlled plus investigator-controlled rescue administration and the total number of button pushes were measured at 2, 4, 8, 12, 24, and 48 hours after surgery. In addition, C-reactive protein (CRP) levels were checked on the operation day and postoperative days 1, 2, 3, and 5. VAS scores were significantly lower in group L than group C until 24 hours after surgery. Fentanyl consumption was lower in group L than group C until 12 hours after surgery. Moreover, additional fentanyl injections and the total number of button pushes appeared to be lower in group L than group C (P < 0.05). The CRP level tended to be lower in group L than group C, especially on postoperative day 1 and 2 and appeared to be statistically significant. The satisfaction score was higher in group L than group C (P = 0.024). Intravenous lidocaine infusion during an operation reduces pain after a laparoscopic colectomy.

Single-port endoscopic mesocolic and mesorectal excision using an extraperitoneal approach

BACKGROUND

The extraperitoneal rectal dissection via a transanal approach facilitates the mesorectal dissection. The retroperitoneal approach for mesocolic excision may also offer some similar advantages. To complete the lymphadenectomy of extraperitoneal mesorectal resection, we developed an innovative approach for upper rectal and mesocolic excision via an exclusive retroperitoneal dissection using a single-port access at the site of the future stomy.

METHODS

This study was a prospective pilot study and was conducted between 2013 and 2015 at two oncologic centers. Five consecutive patients, with ano-rectal cancer requiring permanent stoma, underwent this procedure.

RESULTS

The bowel was never touched or mobilized to perform the lymphadenectomy, and no Trendelenburg was required. The median operative duration was 300 min (range 205-310). The quality of the surgical plane was classified as good (mesorectal) in the five patients. The median circumferential and distal margins were, respectively, 5 mm (range 1-20) and 20 mm (range 5-25). The median number of harvested lymph nodes was 11 (range 5-18). No laparotomy or multiport laparoscopy was required. There was no death. Two patients had perineal wound dehiscence (one minor and one major).

CONCLUSIONS

The mesocolic excision via a retroperitoneal approach is feasible, completes naturally the transanal mesorectal excision and may confer several advantages including no morbidity of small bowel manipulation or Trendelenburg position. Further studies are required to analyze this approach.

Impact of nitrous oxide on the haemodynamic consequences of venous carbon dioxide embolism: An experimental study

BACKGROUND

Nitrous oxide (N2O) is still considered an important component of general anaesthesia. However, should gas embolisation occur as result of carbon dioxide (CO2) pneumoperitoneum, N2O may compromise safety, as the consequences of a gas embolus consisting of a combination of CO2 and N2O may be more severe than CO2 alone.

OBJECTIVE

This experimental study was designed to compare the cardiopulmonary consequences of gas embolisation with a N2O/CO2 mixture, or CO2 alone.

DESIGN

Experimental study.

SETTING

Research Institute Against Digestive Cancer laboratory, Strasbourg, France.

ANIMALS

Seven Large-White pigs receiving standardised inhalation anaesthesia.

INTERVENTIONS

Each animal, acting as its own control, was studied in two successive experimental conditions - intravenous gas injections of 2 ml kg of 100% CO2 and 2 ml kg of a gas mixture consisting of 10% N2O and 90% CO2.

MAIN OUTCOMES MEASURES

Haemodynamic and ventilatory consequences of embolisation with the gases.

RESULTS

We found that the haemodynamic (heart rate, mean arterial blood pressure, central venous pressure, mean pulmonary artery pressure, pulmonary artery occlusion pressure and transoesophageal echocardiography parameters) and ventilatory (arterial oxygen saturation, end-tidal CO2 concentration and mixed venous oxygen saturation) consequences of embolisation with either 100% CO2 or 10% N2O with 90% CO2 were similar.

CONCLUSION

The findings of this study may alleviate concerns that the use of N2O, as a part of a balanced general anaesthesia technique, may have greater adverse consequences should embolisation of pneumoperitoneal gas containing N2O occur.

Case scenario about TEE: Patient with dilated cardiomyopathy undergoing laparoscopic cholecystectomy

A 42-year-old woman, who presented with DCM (American Society of Anesthesia, ASA class IV), suffered from gallstone for years, and was scheduled for laparoscopic cholecystectomy. Echocardiography demonstrated a severely dilated left ventricle with global hypokinesia and reduction of left ventricular systolic function, ejection fraction (EF) 34% with mild mitral regurgitation and severe tricuspid regurgitation. After intubation, a transesophageal echocardiography (TEE) probe was inserted. When the IAP was gradually ascended to 14 mmHg during the laparoscopy, EF fell to 19% and the systolic pressure fell to 78 mmHg and TEE showed severely poor wall motion. But the central venous pressure (CVP) still showed about 4 mmHg throughout the whole procedure. After decreasing the IAP to 10 mmHg, we adjusted the rate of pacemaker to 70 times per minute then the systolic pressure was kept at around 100 mmHg, and the diastolic pressure was kept at 60 mmHg. EF was 30% after the reduction of IAP and the adjusting of the heart rate set. TEE is a helpful monitor in anesthesia management of patients with DCM during noncardiac surgery and CVP is useless especially for the procedure with severe hemodynamic effects.

Effects of pneumoperitoneal pressure and position changes on respiratory mechanics during laparoscopic colectomy

Background

This study was designed to assess the effects of pneumoperitoneal pressure (PP) and positional changes on the respiratory mechanics during laparoscopy assisted colectomy.

Methods

Peak inspiratory pressure, plateau pressure, lung compliance, and airway resistance were recorded in PP of 10 mmHg and 15 mmHg, with the position change in 5 steps: head-down at 20°, head-down at 10°, neutral position, head-up at 10° and head-up at 20°.

Results

When the patient was placed head-down, the position change accentuated the effects of pneumoperitoneum on respiratory mechanics. However, when the patient was placed in a head-up position during pneumoperitoneum the results showed no pattern. In the 20° head-up position with the PP being 10 mmHg, the compliance increased from 30.6 to 32.6 ml/cmH₂O compared with neutral position (P = 0.002). However with the PP being 15 mmHg, the compliance had not changed compared with neutral position (P = 0.989). In 20° head-down position with the PP of 10 mmHg, the compliance was measured as 24.2 ml/cmH₂O. This was higher than that for patients in the 10° head-down position with a PP of 15 mmHg, which was recorded as 21.2 ml/cmH₂O. Also in the airway resistance, the patient in the 20° head-down position with the PP of 10 mmHg showed 15.8 cmH₂O/L/sec, while the patient in the 10° head-down position with the PP of 15 mmHg showed 16.2 cmH₂O/L/sec of airway resistance. These results were not statistically significant but still suggested that the head-down position accentuated the effects of pneumoperitoneum on respiratory mechanics.

Conclusions

Our results suggest that respiratory mechanics are affected by the patient position and the level of PP - the latter having greater effect.

Anesthetic course and complications that were encountered during endoscopic thyroidectomy -A case report-

Endoscopic thyroidectomy is gaining popularity, but it can increase the risk of certain complications. Carbon dioxide insufflation in the neck may cause adverse effects on hemodynamic and ventilatory aspects. We report the anesthetic course and complications that were encountered during endoscopic thyroidectomy. Although the surgery was successful, the patient developed signs of hypercarbia, subcutaneous emphysema and pneumothorax.

Surgical Tension Pneumothorax during Laparoscopic Repair of Massive Hiatus Hernia: A Different Situation Requiring Different Management

During laparoscopic repair of massive hiatus hernia, surgical dissection can breach the parietal pleura allowing insufflating carbon dioxide to rapidly expand the pleural space, causing a tension pneumothorax. This extrapulmonary pneumothorax involves no damage to the lung parenchyma. Its rapid resolution is aided by the high solubility of carbon dioxide and it will not refill once the procedure is completed. In this series of 50 massive hiatus hernia repairs the incidence of pneumothorax was 22% (11/50), with two of these being bilateral. Cardiovascular compromise occurred in 91% of those (10/11). The aetiology, pathophysiology and management of this intraoperative capnothorax differ significantly from that of a pneumothorax secondary to lung trauma or occurring during other types of laparoscopy. Understanding the relevant pleural anatomy and pathophysiology of this condition allowed conservative management in all cases and avoided the need for chest drains, open surgery or abandonment of the procedure.

Fatal central venous air embolism: a rare complication of esophageal dilation by rendezvous

BACKGROUND

Esophageal dilation by rendezvous is a useful technique for the treatment of complicated esophageal strictures.

METHODS AND RESULTS

We present a case of a 74-year-old man with chronic dysphagia caused by a complete cervical esophageal stricture that developed after external beam radiotherapy for treatment of papillary thyroid carcinoma. During attempted dilation using the rendezvous technique, the patient suffered a fatal pulmonary air embolism. The technique of esophageal dilation by rendezvous, complications, and risk factors for development of venous air embolism are discussed.

CONCLUSION

To the best of our knowledge, this is the first report in the literature of fatal venous air embolism after dilation by rendezvous.

Recognition and management of major vessel injury during laparoscopy

Laparoscopy is one of the most commonly performed procedures in the United States. Injury to a major retroperitoneal vessel occurs in 0.3% to 1.0% of procedures, most commonly during laparoscopic entry while placing the Veress needle or primary trocar. Fatal outcome can be related to massive gas embolism or exsanguination. Recommended treatment for gas embolism can range from supportive measures to external chest compression and insertion of a central line to withdraw gas from the right side of the heart. Recommended treatment of major vessel injury with massive hemorrhage consists of rapid laparotomy and control of hemorrhage using direct pressure until a surgeon experienced in vascular procedures arrives. When a major vessel injury occurs in a surgical facility distant from a medical center and without an available surgeon with vascular experience, based on the trauma literature, we recommend temporary control of blood loss using abdominal packing and closure (i.e., "damage control surgery") and judicious resuscitation (i.e., "damage control resuscitation") before transportation to a medical center.

[Special features of laparoscopic operations from an anesthesiologic viewpoint: a review]

The value of laparoscopic procedures has increased over the last decade. Many patients undergoing laparoscopic surgery also have coexisting diseases. The hemodynamic effects of intraperitoneal carbon dioxide insufflation depend on the extent of intraperitoneal pressure, severity of preexisting cardiopulmonary diseases, volume state of the patient and alterations of acid-base balance due to a capnoperitoneum. In addition to endocrinologic reactions, patient positioning also affects hemodynamic parameters. In high risk patients extended cardiopulmonary monitoring with an arterial line and repeated blood gas analysis is recommended intraoperatively, in addition to assessment of end-expiratory CO(2). In this patient group the intra-abdominal pressure should be maintained in the range of 5-7 mmHg.

Laparoscopic versus non-laparoscopic-assisted ventriculoperitoneal shunt placement in adults. A retrospective analysis

BACKGROUND

Ventriculoperitoneal shunts and distal shunt revisions bear a high risk of distal malfunction, especially in patients with previous abdominal pathologies as well as in obese patients. We performed laparoscopy-guided distal shunt placement or revision for patients with and without a positive abdominal history. We review the indications, techniques, complications, and long-term outcomes of these cases and compare the results to those of patients operated without laparoscopic guidance.

METHODS

A total of 211 distal shunt procedures were performed in our institute between January 2001 and December 2005, 59 of which were laparoscopically guided, and 152 were not. Of the 211 procedures, 177 were placement of new shunt systems, and 34 were distal revisions. A total of 33 procedures were performed in 25 patients with a history of abdominal surgery or inflammatory bowel disease; 15 procedures were operated with laparoscopic guidance.

RESULTS

The short-term complication and outcome rates were similar between the laparoscopy group and the other patients. Among the patients with new shunts, the long-term distal malfunction rate was lower in the laparoscopy group compared with the nonlaparoscopy group (4% vs 10.3%, respectively; P = .17). No patients in the laparoscopy group and 6 patients operated by other techniques had distal malfunction. There was 1 laparoscopy-related mortality and no morbidity.

CONCLUSIONS

Laparoscopy is not routinely indicated in distal shunt placement or revision. However, a laparoscopy-guided procedure may lower the rate of distal malfunction in patients with previous abdominal surgeries.

Carbon dioxide embolism during laparoscopic cholecystectomy due to a patent paraumbilical vein

Carbon dioxide embolism is a rare but potentially fatal complication of laparoscopic surgery. The most common cause is inadvertent injection of carbon dioxide into a large vein or solid organ during initial peritoneal insufflation. We describe a case of carbon dioxide embolism in a 13-year-old boy during an elective laparoscopic cholecystectomy, caused by injection of carbon dioxide into a large paraumbilical vein. The clinical manifestations of carbon dioxide embolism were hypotension, bradycardia, and an abrupt drop in end-tidal CO2. He subsequently did well and had no sequelae. Carbon dioxide embolism is a recognized complication of laparoscopic surgery, although the risk to the patient may be minimized by the surgical team's awareness of the problem, continuous intraoperative monitoring of end-tidal CO2, and using an open technique for initial access to the peritoneum.

Tracheal tube tip displacement during laparoscopy in children

The risk of endobronchial intubation during laparoscopy because of displacement of the tip of the tracheal tube is a well known problem in adults. Laparoscopy in children is increasingly performed, but there are no data available regarding the above problem. We prospectively studied 46 children aged 2 months to 15.7 years (median 4.2 years) undergoing laparoscopy. After tracheal intubation with the Microcuff Pediatric Endotracheal Tube, with the 'intubation depth marking' of the tube at the vocal cords, the distance from the tracheal tube tip to the carina was endoscopically measured with the patient in the neutral position and with 20 degrees head-down tilt, both with and without capnoperitoneum. Maximal displacement of the tip of the tracheal tube tip in cm was 0.5+(0.05xage (years)) for 20 degrees head-down tilt, 0.6+(0.09xage (years)) for capnoperitoneum alone, and 1.2+(0.11xage (years)) for 20 degrees head-down tilt with capnoperitoneum. In no patients did endobronchial intubation occur with the tracheal tube placed according to the intubation depth marking.

Acoustic Monitoring of Double-Lumen Ventilated Lungs for the Detection of Selective Unilateral Lung Ventilation

One-lung intubation (OLI) is among the most common complications of endotracheal intubation. None of the monitoring tools now available has proved effective for its early detection. In this study we investigated the efficacy of acoustic analysis for the detection of OLI. We collected lung sounds from 11 patients undergoing thoracic surgery requiring the placement of a double-lumen tube. Recordings of separate lung ventilation were performed after induction and confirmation of adequate tube positioning, before surgery. Samples of lung sounds were collected by three piezoelectric microphones, one on each side of the chest and one on the right forearm, for background noise sampling. The samples were filtered, the signals' energy envelopes were calculated, and segmentation to breath and rest periods was performed. Each respiration was classified into one of the three categories: bilateral ventilation, selective right-lung ventilation, or selective left-lung ventilation, on the basis of the ratio between the energy signals of each lung. OLI was accurately identified in 10 of the 11 patients during right OLI and in all 11 patients during left OLI. This study suggests that acoustic monitoring is effective for the detection of selective lung ventilation and may be useful for early diagnosis of OLI.

Diagnostic laparoscopy and ultrasonography for colorectal liver metastases

BACKGROUND AND AIMS

To evaluate diagnostic laparoscopy (DL) and laparoscopic ultrasonography (LUS) in the diagnostic workout of patients with colorectal liver metastases, who were considered to have resectable disease after multi detector computed tomography (MDCT).

MATERIAL AND METHODS

The medical records of 45 patients, 22M/23F, mean age 62.0 (+/-10.6), who were considered to have resectable liver metastases after CT-scan, were analysed.

RESULTS

DL and LUS could not be performed in 7 patients (16%) because of adhesions. Unresectable disease was detected by DL in 3 patients (7%), in all cases due to carcinosis. Additional lesions in the liver were detected by DL in 2 cases (4%), none of these making the patient unresectable. LUS showed additional lesions in 3 patients (7%), which in one case (2%) made the patient unresectable. None of the patients in the present study experienced adverse effects to DL or LUS.

CONCLUSION

DL and LUS, due to the low efficacy with regard to avoid unnecessary laparotomies and the relative high failure rate because of adhesions, should not be a routine part of the diagnostic work out in patients with colo-rectal liver metastases.

Model-Based Detection of Endobronchial Intubation

To detect endobronchial intubation (EBI) noninvasively in real time, we developed a novel, automated, lumped model-based approach. The model uses routinely monitored airway pressure and flow as inputs. The specificity of the method in detecting EBI was determined by testing events of stiff chest wall (SCW) in the absence of EBI. EBI was induced in 10 anesthetized, paralyzed, and mechanically ventilated mongrel dogs (19-45 kg) by advancing the endotracheal tube into the right mainstem bronchus. The event of SCW was created by wrapping a pressure cuff around the chest. Airway pressure and flow were continuously recorded at the mouth, and respiratory impedance was estimated from these signals. Model parameters were iteratively identified until the root mean square error between the respiratory and model-predicted impedance was minimum. The change in model parameters during EBI from baseline was analyzed. In nine of 10 cases, it was determined that during EBI, the model's compliance element (C1) decreased > or =50% and model's resistance element (R2) changed < or =10-fold from baseline. Testing this rule on 40 cases of SCW, four false positives were obtained. During SCW, R1 and R2 increased, whereas C2 decreased significantly from baseline. This preliminary study is a promising step toward noninvasive, real-time detection of EBI to aid clinicians in decision making.

Anesthesia for laparoscopy: a review

Laparoscopy is the process of inspecting the abdominal cavity through an endoscope. Carbon dioxide is most universally used to insufflate the abdominal cavity to facilitate the view. However, several pathophysiological changes occur after carbon dioxide pneumoperitoneum and extremes of patient positioning. A thorough understanding of these pathophysiological changes is fundamental for optimal anesthetic care. Because expertise and equipment have improved, laparoscopy has become one of the most common surgical procedures performed on an outpatient basis and to sicker patients, rendering anesthesia for laparoscopy technically difficult and challenging. Careful choice of the anesthetic technique must be tailored to the type of surgery. General anesthesia using balanced anesthesia technique including several intravenous and inhalational agents with the use of muscle relaxants showed a rapid recovery and cardiovascular stability. Peripheral nerve blocks and neuraxial anesthesia were both considered as safe alternative to general anesthesia for outpatient pelvic laparoscopy without associated respiratory depression. Local anesthesia infiltration has shown to be effective and safe in microlaparoscopy for limited and precise gynecologic procedures. However, intravenous sedation is sometimes required. This article considers the pathophysiological changes during laparoscopy using carbon dioxide for intra-abdominal insufflation, outlines various anesthetic techniques of general and regional anesthesia, and discusses recovery and postoperative complications after laparoscopic abdominal surgery.

Robot-assisted laparoscopic and open live-donor nephrectomy: a comparison of donor morbidity and early renal allograft outcomes

BACKGROUND

Robot-assisted laparoscopic donor (RALD) nephrectomy, a new procedure for the removal of a kidney from a living donor, was performed on 13 subjects at our centre.

METHODS

The immediate post-operative courses for these donors, and their respective recipients, were compared with those of 13 previous open live-donor nephrectomies (OPEN), performed in our facility.

RESULTS

We found no significant differences between these two donor groups with respect to age, gender, body mass index or renal vasculature. The average operative times and the warm ischaemia times were greater in the RALD group, 185.5'' vs 113.4'' (P = 0.0001) and 7'15'' vs 1'41'' (P = 0.0001), respectively. There was no conversion to the open procedure in the RALD group. The estimated blood loss was slight in both groups. Following nephrectomy, deep venous thrombosis occurred in one RALD patient and acute pyelonephritis in one OPEN patient. The average duration of hospitalization was shorter after the RALD procedure (5.84+/-1.8 days vs 9.69+/-2.2 days, P = 0.0001). The estimated creatinine clearance rate (eClcreat) was equivalent for all donors, at 5 days and 1 month after nephrectomy. All kidneys started functioning immediately after the transplantation. The mean recipient eClcreat (ml/min) was 58.16+/-26.7 for OPEN group kidneys and 62.23+/-17.59 for RALD group kidneys (P = 0.65), 5 days after transplantation.

CONCLUSIONS

RALD nephrectomies were associated with very low morbidity among donors, in which both the operative and warm ischaemia times were of longer duration, but had no observable adverse effects upon short-term graft function.

Delayed tension pneumothorax during surgery

Tension pneumothorax is a life-threatening emergency that rapidly results in cardiopulmonary arrest. It requires prompt diagnosis and treatment. We present 2 cases from our practice, 1 caused by blunt chest trauma and the other resulting from laparoscopic surgery. Both were successfully treated by insertion of a chest tube. The diagnosis and treatment of intraoperative pneumothorax is discussed together with a review of the literature.

Continuous transesophageal echo-Doppler assessment of hemodynamic function during laparoscopic cholecystectomy

STUDY OBJECTIVE

The objective of this study was to examine the utility of the transesophageal echo-Doppler device in evaluating hemodynamic changes during laparoscopic cholecystectomy.

DESIGN

This was a prospective, controlled, observational open study.

SETTING

The study took place in a university hospital.

PATIENTS

Twenty patients with ASA physical statuses II and III undergoing laparoscopic cholecystectomy were enrolled into the study.

INTERVENTIONS AND MEASUREMENTS

A standardized general anesthetic and surgical technique was used for all patients. Similar depth of hypnosis (using bispectral index monitoring) was maintained in all patients. Hemodynamic parameters including mean arterial pressure (MAP), cardiac index (CI), left ventricular (LV) ejection time interval indexed to the heart rate, maximum acceleration, peak velocity, and systemic vascular resistance (SVR) were recorded at predetermined intervals: before incision, after peritoneal CO(2) insufflation and head-up tilt, every 10 minutes thereafter, and after deflation of the abdomen and return to supine position.

MAIN RESULTS

The transesophageal echo-Doppler probe placement was achieved in 3 to 5 minutes in all patients, and the probe position was maintained after creation of pneumoperitoneum and change in positioning. Induction of pneumoperitoneum and head-up tilt resulted in a significant increase in MAP and SVR (P < .05) that remained higher until deflation. The CI, LV ejection time interval indexed to the heart rate (a measure of LV filling), and maximum acceleration (a measure of contractility and global ventricular function) remained stable.

CONCLUSIONS

The transesophageal echo-Doppler device can be used during laparoscopic cholecystectomy. The LV function, as determined by measurement of CI and maximum acceleration, was preserved during laparoscopic cholecystectomy despite significant increases in afterload (ie, MAP and SVR).

Intra-abdominal hypertension and the abdominal compartment syndrome

BACKGROUND

Abdominal compartment syndrome (ACS) occurs when intra-abdominal pressure is abnormally high in association with organ dysfunction. It tends to have a poor outcome, even when treated promptly by abdominal decompression.

METHODS

A search of the Medline database was performed to identify articles related to intra-abdominal hypertension and ACS.

RESULTS

Currently there is no agreed definition or management of ACS. However, it is suggested that intra-abdominal pressure should be measured in patients at risk, with values above 20 mmHg being considered abnormal in most. Abdominal decompression should be considered in patients with rising pressure and organ dysfunction, indicated by increased airway pressure, reduced cardiac output and oliguria. Organ dysfunction often occurs at an intra-abdominal pressure greater than 35 mmHg and may start to develop between 26 and 35 mmHg. The mean survival rate of patients affected by compartment syndrome is 53 per cent.

CONCLUSION

The optimal time for intervention is not known, but outcome is often poor, even after decompression. Most of the available information relates to victims of trauma rather than general surgical patients.

Pneumothorax during laparoscopy

BACKGROUND

Pneumothorax is a known complication of laparoscopy, with most pneumothoraces diagnosed postoperatively with conventional chest x-ray. Electrocardiogram (ECG) conduction changes are associated with pneumothorax. In a sheep model, ECG changes were evaluated as a potential indicator of intraoperative pneumothorax. Additionally, resolution rates of helium (He) and carbon dioxide (CO2) pneumothorax were also evaluated in this model.

METHODS

Under general anesthesia, 10 sheep had known volumes (20-100 cc) of either He or CO2 introduced into the left hemithorax. A 12-lead ECG recorded changes associated with the induced pneumothorax. After changes in the ECG plateaued, the gas volume in the hemithorax was increased to 2 L and the resultant pneumothorax was followed for a 2-h period using fluoroscopy to determine resolution rates for the different gas pneumothoraces. Gas volumes were aspirated after 2 h and ECGs were again recorded.

RESULTS

Pneumothorax volumes as low as 20 cc produced consistent ECG changes. The amplitude of the precordial QRS complex was seen to diminish, and this lowering of the QRS amplitude continued as pneumothorax volume increased up to 100 cc. The ECG returned to prepneumothorax patterns with aspiration of the left chest. For different gas pneumothoraces, CO(2) pneumothorax showed almost complete resolution in the 2-h period, whereas He pneumothorax was unchanged.

CONCLUSIONS

Precordial ECG changes appear to be a very sensitive indicator of pneumothorax, with very small pneumothorax (<100 cc) consistently being detected by reduction of the QRS complex amplitude. Intraoperative use of precordial ECG leads could result in rapid identification of pneumothorax during laparoscopic surgery. Carbon dioxide pneumothorax shows near 100% resolution in a 2-h period. This supports recommendations of expectant management in asymptomatic patients with CO(2) pneumothorax. However, He pneumothorax does not resolve spontaneously quickly and may require aspiration even in asymptomatic patients.

Plasma levels of endothelin-1, big endothelin-1 and thromboxane following acute pulmonary air embolism

Acute pulmonary air embolism (APAE) was induced in nine piglets by repeated intravenous bolus injection of room air into a large bore central venous catheter at time=0 min so that the mean pulmonary artery pressure (MPAP) was maintained at two times the baseline value for 4 h. Another five animals served as controls. At time=0, 30, 60, 120, 240 min, circulating arterial plasma levels of endothelin-1 (ET-1), its precursor big ET-1, and thromboxane (Tx), were measured by RIA and EIA, respectively, along with hemodynamics and blood gases. The data showed that following APAE, there was a rapid increase in MPAP and a persistent decrease in Pa(O(2)), while the mean arterial blood pressure and cardiac output remained comparable. Plasma levels of ET-1, big ET-1 and Tx were also increased steadily in these first 4 h. These results showed that during APAE, the resulted changes in the pulmonary vascular and airway tones mediated by these potent mediators could explain the observed pulmonary hypertension and the deterioration of gas exchange.

Spontaneous pneumothorax during laparoscopic adrenalectomy secondary to a congenital diaphragmatic defect

Despite its obvious benefits, laparoscopic surgery is not free of complications. It may cause significant physiologic changes and technical mishaps. Pneumothorax has been described as a complication of almost any type of laparoscopic surgery. We report a case of tension pneumothorax during laparoscopic adrenalectomy secondary to a congenital diaphragmatic defect and describe our treatment.

Anaesthetic considerations for laparoscopic cholecystectomy

Minimally invasive surgical procedures aim to minimize the trauma of the interventional process but still achieve a satisfactory therapeutic result. Tissue trauma is significantly less than that with conventional open procedures, offering the advantages of reduced post-operative pain, shorter hospital stay, more rapid return to normal activities and significant cost savings. Laparoscopic cholecystectomy is now a routinely performed procedure and has replaced conventional open cholecystectomy as the procedure of choice for symptomatic cholelithiasis. Public expectation and developments in instrumentation have fuelled this change. The physiological effects of intraperitoneal carbon dioxide insufflation combined with variations in patient positioning can have a major impact on cardiorespiratory function, particularly in elderly patients with co-morbidities. Intra-operative complications may include traumatic injuries associated with blind trocar insertion, gas embolism, pneumothorax and surgical emphysema associated with extraperitoneal insufflation. Appropriate monitoring and a high index of suspicion can result in early diagnosis of, and treatment of, complications. Laparoscopic cholecystectomy has proven to be a major advance in the treatment of patients with symptomatic gallbladder disease.