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Biomedical subjects

D E Litwin

Publications and source records attributed to D E Litwin.

At least 19 recordsLinked to original sources

Elevated intrahepatic pressures and decreased hepatic tissue blood flow prevent gas embolus during limited laparoscopic liver resections.

BACKGROUND: As new techniques are emerging for laparoscopic liver resections, concerns have been raised about the development of gas embolus related to the CO(2) pneumoperitoneum. We hypothesized that elevated intrahepatic vascular pressures and decreased hepatic tissue blood flow (LQB) would prevent gas embolus during laparoscopic liver resections under conventional pneumoperitoneum. METHODS: Intrahepatic vascular pressures and LQB were measured in nine pigs with varying CO(2) pneumoperitoneum. Gas embolus was determined after hepatic incision by monitoring pulmonary arterial pressure (PAP), hepatic venous PCO(2), systemic blood pressure (SBP), and suprahepatic vena cava ultrasound. RESULTS: As the pneumoperitoneum was increased from 0 to 15 mmHg, intrahepatic vascular pressures increased significantly (p < 0.05), while LQB decreased significantly (p < 0.05). A 2.0-cm hepatic incision at 4, 8, 15, and 20mmHg produced no ultrasound evidence of gas embolus and no changes in PAP, SBP, or hepatic venous PCO(2) (p = NS). CONCLUSION: These data suggest that the risk of significant embolus under conventional pneumoperitoneum is minimal during laparoscopic liver resections.

Animals↗

Hand-assisted laparoscopic surgery in the United States: an overview.

Hand-assisted laparoscopic surgery (HALS) was developed to bridge the gap between open surgery and advanced laparoscopic surgery. Advantages of the hand in the abdomen include tactile feedback, the ability to palpate, blunt dissection, organ retraction, control of bleeding, and rapid organ removal. There are 3 commercially available devices in the United States, as well as a fourth in Europe and a fifth in Japan. Uses for HALS include procedures requiring intact specimen removal, complex laparoscopic procedures, preventing open conversion, and overcoming a technical obstacle. HALS procedures, such as esophagectomy, gastrectomy, hepatectomy, pancreatectomy, splenectomy, bariatric surgery, colectomy, nephrectomy, hysterectomy, and aortobifemoral bypass, have all been reported in the literature. Improvement in instrumentation, specifically with newer generation devices, will allow HALS to become more popular. We advocate the use of HALS specifically for laparoscopic colectomy, laparoscopic splenectomy for massive splenomegaly, and for living-related donor nephrectomy.

Colectomy↗

Transperitoneal laparoscopic exposure for lumbar interbody fusion.

STUDY DESIGN: A prospective clinical trial of the transperitoneal laparoscopic approach to the lumbar spine in a consecutive series of patients undergoing anterior lumbar interbody fusion. OBJECTIVES: To determine safety and effectiveness, and to document technique and perioperative complications of a laparoscopic exposure for lumbar interbody fusion. SUMMARY OF BACKGROUND DATA: With the widespread adoption of laparoscopic techniques, the benefits of minimal access surgery are now well recognized--in general, gynecologic and urologic surgery. Only recently have minimal access techniques been applied to spinal procedures. METHODS: Forty-seven patients with symptomatic degenerative disc disease underwent transperitoneal laparoscopic exposure of the lumbar spine to facilitate implantation of cylindrical threaded interbody fusion cages. These patients were prospectively followed and all perioperative considerations and complications were documented and analyzed. The surgical technique of laparoscopic exposure will be described. RESULTS: The laparoscopic approach was attempted in 47 consecutive patients. Forty-four were completed laparoscopically--36 single level fusions, seven two level fusions, and one three level fusion. Early in the series, conversion to open surgery was required in one patient (case #3) because of bleeding from the presacral veins which hindered the view. In one case, mobilization of the great vessels proved to be difficult, and in one other case the patient could not tolerate abdominal insufflation. The mean blood loss for the entire group was 105 mls. Complications related to the endoscopic exposure were few. There were no injuries to major vascular structures or to bowel, and no mortalities. In two patients, the cages were malpositioned necessitating repeat endoscopic exposure for cage realignment. One patient required a laparotomy for a postoperative small bowel obstruction. The median postoperative stay was 4 days. CONCLUSIONS: Transperitoneal laparoscopic exposure for single or multiple level, anterior lumbar interbody fusion can be performed with low risk. Experience in open anterior spinal surgery and laparoscopic general surgery is vital in minimizing the risks.

Adult↗

The feasibility and accuracy of diagnostic laparoscopy in the septic ICU patient.

BACKGROUND: Systemic inflammatory response syndrome (SIRS) and sepsis of unknown origin are common complications of critically ill patients in the ICU. These patients frequently have unreliable clinical exams and are candidates for exploratory laparotomy. Although abdominal CT is commonly used because it is less invasive than laparotomy, it is often unreliable or unobtainable. Bedside laparoscopy is an alternative technique that may be more accurate than CT in selected patients and less invasive than laparotomy. METHODS: We performed diagnostic laparoscopy (DL) in a series of ICU patients with SIRS/septic state of unknown origin between May 1997 and June 1998. All patients were unstable and required significant respiratory and hemodynamic support. Laparoscopy was either performed in the ICU at the patient's bedside or in the operating room. CT scan of the abdomen had been performed on most of the patients who were stable enough to transport. Confirmation of diagnosis was obtained either by laparotomy, autopsy, or clinical recovery. RESULTS: Among the 17 eligible patients, 16 underwent successful DL. Insufflation was impossible in one patient because of high intraabdominal pressure. Bedside evaluations were performed in 14 of the 17 patients. There were no complications from the laparoscopy. Six patients were identified as positive (four intestinal ischemia, two cholecystitis); the other 10 had negative explorations. Follow-up on two patients with negative laparoscopy was incomplete due to denied postmortem. Laparoscopic diagnoses were confirmed in the remaining 14 patients by laparotomy (six cases), postmortem (three cases), or recovery (five cases), with an accuracy of 100%. The overall accuracy of abdominal CT obtained in nine of the 14 patients was 33%. CONCLUSIONS: DL in a select group of critical ICU patients is safe and accurate, whereas CT scan tends to be inaccurate and is often unobtainable due to patient instability. Performing the procedure at the bedside can expedite the diagnosis, eliminate the burden for transfer, and save on anesthesia and operating room charges.

Feasibility Studies↗

Suturing and knotting techniques for thoracoscopic cardiac surgery.

The preceding description of E-CABG may seem excessively detailed, even redundant, for trained cardiac surgeons; however, the authors' extensive experience with training surgeons on endoscopic techniques suggests that, despite a high level of proficiency and dexterity that a surgeon may possess in open surgery, becoming equally proficient and dexterous in the endoscopic environment is not simple. Participating in an in-depth, systematic endoscopic microvascular surgery training program in a laboratory setting is essential before applying the previously described E-CABG techniques in humans. The E-CABG procedure is one of the most challenging endoscopic techniques. Successful completion of this procedure requires that the surgeon be motivated to succeed and willing to invest the time and effort necessary to develop the new skills. Also critical is the avoidance of the temptation to use devices and systems that promise to obviate the need to bother with learning these difficult endoscopic skills. Long term results of the minimally invasive approach remain to be defined. However, some early studies of port-access procedures are encouraging. To date, a prospective randomized clinical trial comparing conventional LAD bypass to E-CABG has not been conducted. Although most investigators believe that long term patency of the IMA to the LAD using either technique should be the same, this is as yet unproven. Nonetheless, the adaption of endoscopic skills by the cardiac surgeon will further advance the evolution of this specialty.

Coronary Artery Bypass↗

Hand-assisted laparoscopic aortobifemoral bypass grafting.

OBJECTIVE: Aortobifemoral bypass grafting is a durable operation for arterial reconstruction in patients with symptomatic aortoiliac occlusive disease. In several small laparoscopic series technically demanding aortic operations have been described that have not gained widespread acceptance or applicability. To simplify the laparoscopic approach to the aorta, we have developed a technique of aortobifemoral bypass grafting that uses hand-assisted laparoscopic surgery (HALS) to minimize the complexity of aortic dissection and reconstruction. METHODS: Five patients with symptomatic aortoiliac occlusive disease underwent successful HALS aortobifemoral bypass grafting. With the use of a specialized sleeve device (Hand-Port), an operative hand was introduced into the laparoscopic field while pneumoperitoneum was maintained. Laparoscopic dissection of the infrarenal aorta was then performed with retraction provided by the operative hand. Proximal aortic anastomosis was performed with an open technique through the same 7.5-cm Hand-Port incision, and femoral anastomoses were performed in the standard fashion. RESULTS: Five hand-assisted laparoscopic aortobifemoral bypass grafts were performed (two end-to-end, three end-to-side proximal anastomoses). Mean operative time was 231 minutes. Mean blood loss was 440 mL. All patients underwent extubation immediately after surgery, were ambulatory on postoperative day (POD) 1, and were tolerating their diet by POD 3. The mean length of hospital stay was 3.8 days. One patient was discharged on POD 5 and started a clear liquid diet after a self-limiting postoperative ileus. All patients were asymptomatic and back to full activity/work by 14.6 days postoperatively, on average (range, 11-20 days). CONCLUSION: The HALS offers the advantages of tactile feedback, flexible retraction, and the introduction of conventional surgical instruments, all of which extend laparoscopic surgery and its established benefits to a wide array of more complex surgical problems, including major vascular surgery. Ease of performance, shorter hospital stays, and faster recovery times all suggest that HALS may become a valuable adjunct to conventional aortobifemoral bypass grafting.

Adult↗

Hand-assisted laparoscopic surgery (HALS) with the HandPort system: initial experience with 68 patients.

OBJECTIVE: To evaluate the feasibility and potential benefits of hand-assisted laparoscopic surgery with the HandPort System, a new device. SUMMARY BACKGROUND DATA: In hand-assisted laparoscopic surgery, the surgeon inserts a hand into the abdomen while pneumoperitoneum is maintained. The hand assists laparoscopic instruments and is helpful in complex laparoscopic cases. METHODS: A prospective nonrandomized study was initiated with the participation of 10 laparoscopic surgical centers. Surgeons were free to test the device in any situation where they expected a potential advantage over conventional laparoscopy. RESULTS: Sixty-eight patients were entered in the study. Operations included colorectal procedures (sigmoidectomy, right colectomy, resection rectopexy), splenectomy for splenomegaly, living-related donor nephrectomy, gastric banding for morbid obesity, partial gastrectomy, and various other procedures. Mean incision size for the HandPort was 7.4 cm. Most surgeons (78%) preferred to insert their nondominant hand into the abdomen. Pneumoperitoneum was generally maintained at 14 mmHg, and only one patient required conversion to open surgery as a result of an unmanageable air leak. Hand fatigue during surgery was noted in 20.6%. CONCLUSIONS: The hand-assisted technique appeared to be useful in minimally invasive colorectal surgery, splenectomy for splenomegaly, living-related donor nephrectomy, and procedures considered too complex for a laparoscopic approach. This approach provides excellent means to explore, to retract safely, and to apply immediate hemostasis when needed. Although the data presented here reflect the authors' initial experience, they compare favorably with series of similar procedures performed purely laparoscopically.

Abdomen↗

A meta-analysis of laparoscopic versus open appendectomy in patients suspected of having acute appendicitis.

OBJECTIVE: To determine if any significant differences exist between laparoscopic appendectomy (LA) and open appendectomy (OA). DESIGN: A meta-analysis of randomized controlled trials (RCTs) comparing LA to OA. DATA SOURCES: An extensive literature search was conducted for appropriate articles published between January 1990 and March 1997. Articles were initially retrieved through MEDLINE with MeSH terms "appendicitis" or "appendectomy" and "laparoscopy". Additional methods included cross-referencing bibliographics of retrieved articles, hand searching abstracts from relevant meetings and consultation with a content expert. STUDY SELECTION: Only RCTs published in English in which patients had a preoperative diagnosis of acute appendicitis were included. DATA EXTRACTION: The outcomes of interest included operating time, hospital stay, readmission rates, return to normal activity and complications. The Cochrane Collaboration Review Manager 3.0 was used to calculate odds ratios (OR), weighted mean differences (WMD) and 95% confidence intervals (CI). The random-effects model was used for statistical analysis. DATA SYNTHESIS: Twelve trials met the inclusion criteria. Because there were insufficient data in some trials, operating time, hospitalization and return to work were assessed in only 8 trials. Mean operating time was significantly longer with LA (WMD 18.10 minutes, 95% CI 12.87 to 23.15 minutes). There were fewer wound infections in LA (OR 0.40, 95% CI 0.24 to 0.69), but no significant differences in intra-abdominal abscess rates (OR 1.94, 95% CI 0.68 to 5.58). There was no significant difference in the mean length of hospital stay (WMD -0.16 days, 95% CI -0.44 to 0.15 days) or readmission rates (OR 1.16, 95% CI 0.54 to 2.48). However, the return to normal activity was significantly earlier with LA (WMD -5.79 days, 95% CI -7.38 to -4.21 days). Sensitivity analyses did not affect the results. CONCLUSION: This meta-analysis suggests that operating room time is significantly longer, hospital stay is unchanged but return to normal activities is significantly earlier with LA.

Abdominal Abscess↗

Laparoscopic gastrectomy in the porcine model: our initial experience with a new hand-assist device.

Many advanced laparoscopic cases remain technically difficult and are less widely accepted. To a great extent, advanced laparoscopic surgery is handicapped by the loss of a surgeon's tactile sense. The concept of introducing the surgeon's hand as an aid to minimally invasive surgery has been described. We report a new hand-assist device designed to allow the introduction of the surgeon's hand, wrist, and forearm through a small incision in the abdomen to assist laparoscopic surgery with pneumoperitoneum. Important factors in the hand-assist design are ease of use, reliable maintenance of pneumoperitoneum, and minimal hand/arm fatigue, which were met with this device.

Animals↗

Reducing the deleterious effects of intrauterine CO2 during fetoscopic surgery.

The fetoscopic approach to fetal intervention is a promising minimally invasive technique for correcting congenital anomalies in utero. However, expansion of the amniotic cavity with CO2 to visualize the fetus causes fetal hypercarbia and acidosis. We assessed whether maternal hyperventilation during intrauterine CO2 insufflation could attenuate the fetal hypercarbic acidosis. Seven fetal lambs of 105 +/- 2 days (mean +/- SEM) gestation (term = 145 days) were instrumented with a carotid arterial catheter in utero. After 7 +/- 1 days of recovery, fetoscopic exposure was obtained with intrauterine insufflation of CO2 at 10 mmHg of intraamniotic pressure. After 30 min, the ewe was hyperventilated at a mean respiratory rate of 23/min for 30 min under continuous insufflation. The uterus was then deflated and following 1 hr of stabilization, and the same protocol of CO2 pneumometrium was repeated. Fetal and maternal arterial blood was sampled at baseline and at 15 min intervals. Fetal PaCO2 increased during 30 min of CO2 insufflation (50.8 +/- 2.8 vs. 72.3 +/- 5.0 mmHg, P < 0.01); however, this change was reversed (to 51.5 +/- 3.0 mmHg, P < 0.01) by 30 min of maternal hyperventilation. The fetus developed acidosis after 30 min of CO2 pneumometrium (pH 7.350 +/- 0.012 vs. 7.236 +/- 0.026, P < 0.01); this was also reversed (to 7.366 +/- 0.019, P < 0.01) by maternal hyperventilation. These results were reproducible during the second CO2 insufflation challenge. Fetal hypercarbic acidosis during fetoscopy with CO2 insufflation is reduced by maternal hyperventilation.

Acidosis↗

Laparoscopic groin hernia surgery: the TAPP procedure. Transabdominal preperitoneal hernia repair.

OBJECTIVE: To describe the technique and results of laparoscopic transabdominal preperitoneal (TAPP) hernia repair. DESIGN: A case series, with a detailed description of the operative technique. SETTING: A university affiliated hospital. PATIENTS: A consecutive series of 554 patients (494 male, 60 female) who underwent laparoscopic hernia repair in a single institution. The mean follow-up was 14 months. INTERVENTIONS: Laparoscopic TAPP hernia repair was performed in almost all patients. Simple closure was performed in a patient with a strangulated hernia, and a mesh-based repair was used in a patient with bilateral obturator hernias. MAIN OUTCOME MEASURES: Complications and recurrence. RESULTS: The laparoscopic TAPP repair was successful in 550 of the 554 patients who underwent 632 hernia repairs. conversion was necessary in 4 patients. Complications were infrequent and there were no recurrences. Only 3.4% of patients were lost to follow-up. The most frequent complications were urinary retention (27) and hematoma and seroma (38) in the early postoperative period. Neuralgia (11) and hydrocele (10) also occurred. Mesh infection occurred in only 1 patient and port-site hernias in 3 patients. there was 1 death from an acute myocardial infarction. CONCLUSION: Laparoscopic TAPP hernia repair is associated with an exceedingly low recurrence rate and an acceptable complication rate.

Adolescent↗

Anatomic thoracoscopic lobectomy (ATL) without minithoracotomy: preliminary experience.

UNLABELLED: The purpose of this review is to outline our experience with a completely thoracoscopic approach to major pulmonary resection (lobectomy). There were 23 patients in this study selected by the usual criteria of resectability. The preoperative workup included chest x-ray, pulmonary function studies, computed tomography (CT) of the chest and abdomen, bronchoscopy, mediastinoscopy, and brain and bone scans in the majority of patients. ATL was attempted in 23 patients. In four patients the procedure was converted to the "open" approach for the following reasons: inability to identify the location of the primary lesion (two patients), obscurative bleeding (one patient), and inability to diagnose the pathology (one patient). The underlying pathology of the ATL group was as follows: bronchiolitis obliterans-organizing pneumonia = 1, granuloma = 2, non-small cell lung cancer = 14, solitary colonic metastases = 2. The breakdown by site of the 19 ATL resections is as follows: right upper lobe = 5, right middle lobe = 1, right lower lobe = 1, right upper and right middle lobes = 1, left upper lobe = 6, left lower lobe = 5. Group A patients (n = 11) were those who had no postoperative complications. Length of stay was short, ranging from 4 to 8 days, median 5 days. Group B patients (n = 8) had complications (prolonged air leak = 4, supplemental postoperative oxygen requirement = 3, pain control = 1) and stayed longer (range 10-21 days, median 13). There were no deaths, no blood transfusions, no chest tube reinsertions and no reoperations. The most significant complication in the ATL group was prolonged air leak in one patient (21 days). CONCLUSIONS: (a) ATL without minithoracotomy is feasible; (b) ATL has potential benefits in terms of reduction of pain and hospital stay; (c) ATL had better cosmetic and functional results.

Adult↗

Technetium 99m pentavalent dimercaptosuccinic acid and thallium 201 in detecting recurrent medullary carcinoma of the thyroid.

To compare the effectiveness of thallium chloride 201 and technetium 99m pentavalent dimercaptosuccinic acid in evaluating medullary carcinoma of the thyroid (MCT), eight patients with a history of MCT underwent imaging with both radiopharmaceuticals. Thallium 201 consistently gave superior images, as well as providing one less false-negative scan. Positive scans were obtained in patients with elevation of basal calcitonin levels to more than 1,000 ng/L. All of the patients with positive scans had clinical evidence of local recurrence. Improved imaging with thallium 201 was obtained by early scanning.

Calcitonin↗

History of laparoscopic surgery.

Since the beginning of the 20th century physicians have promoted laparoscopy as a valuable adjunct to the diagnosis of diseases of the abdominal cavity. Laparoscopy, however, failed to become popular among abdominal surgeons until the advent of laparoscopic cholecystectomy. This single new operative approach to the treatment of gallbladder stones gave rise to such enthusiasm among general surgeons that other innovative laparoscopic procedures are now being promoted in ever-increasing numbers. The general surgeon has again become the leader in the introduction of a new surgical approach. This new technique must be developed with great care, and there must be rigorous criteria for its use, critical analysis of the technique and honest reporting of results.

Cholecystectomy↗

Laparoscopic surgery--basic armamentarium.

The introduction of laparoscopic techniques into standard intracavitary surgery has received widespread acceptance in North American surgical practice in a very short time. To complete these procedures successfully a basic armamentarium is required by surgeons. The equipment should provide safe conduct of the procedure and maximum flexibility in the types of surgical procedures to be undertaken. The basic laparoscopic equipment needed to facilitate minimal-access-site surgery is reviewed, from the operating table and lighting in the operating room through optics, cameras and television monitors to the instruments and agents needed for the surgical techniques and for securing hemostasis.

Hemostasis, Surgical↗

Laparoscopic cholecystectomy: strategy and concerns.

After briefly describing the first laparoscopic cholecystectomy performed by Philippe Mouret, the authors review some of the differences in strategy, management and concerns between conventional and laparoscopic cholecystectomy. They address the problems relating to the required skills of triangulation and camera handling, the presence of common-duct stones and concomitant disease, the issues of drainage, hemostasis, access in difficult cases, iatrogenic trauma to the bile ducts and pertinent differences in cardiorespiratory function.

Cholangiography↗

Laparoscopic cholecystectomy: trans-Canada experience with 2201 cases.

The authors carried out a prospective review of the initial and consecutive experience with laparoscopic cholecystectomy of 58 surgeons from 31 teaching and nonteaching institutions throughout Canada. The perioperative morbidity of 2201 cases is described, with special attention to iatrogenic complications. The data suggest that complications, including bile-duct injury, are not frequent. Pneumonia and wound infection rates appear lower than after open surgery. There were no deaths. Laparoscopic cholecystectomy is replacing open cholecystectomy for the management of symptomatic cholelithiasis.

Adolescent↗