Anuria during pneumoperitoneum in infants and children: a prospective study

Prematurity is a critical risk factor for respiratory failure after early inguinal hernia repair under general anesthesia

INTRODUCTION

The purpose of this study was to determine the earliest timing of inguinal hernia repair under general anesthesia with minimized risk for respiratory complications during postoperative course.

METHODS

We performed a monocentric analysis of patient records of premature and full-term infants undergoing inguinal hernia repair between 2009 and 2016. In addition to demographic and medical parameters, preexisting conditions and the perioperative course were recorded.

RESULTS

The study included 499 infants (preterm n = 285; full term n = 214). The number of subsequently ventilated patients was particularly high among preterm infants with bronchopulmonary dysplasia, up to 45.3% (p < 0.001). Less than 10% of subsequent ventilation occurred in preterm infants after 45 weeks of postmenstrual age at the time of surgery or in patients with a body weight of more than 4,100 g. Preterm infants with a bronchopulmonary dysplasia had an increased risk of apneas (p < 0.05). Only 10% of the preterm babies with postoperative apneas weighed more than 3,600 g at the time of surgery or were older than 44 weeks of postmenstrual age.

CONCLUSION

Our data indicate that after the 45th week of postmenstrual age and a weight above 4,100 g, the risk for respiratory failure after general anesthesia seems to be significantly decreased in preterm infants.

Evaluation of renal oxygenization in laparoscopic pediatric surgery by near infrared spectroscopy

PURPOSE

Increased intraabdominal pressure IAP may reduce renal blood flow (RBF). The study aims to evaluate the pneumoperitoneum effect on RBF by comparing renal regional oxygen saturation index (rSrO2) measured by near-infrared spectroscopy (NIRS) in pediatric patients having laparotomy and laparoscopy.

METHODS

Of 58 patients having laparoscopy and laparotomy, 18 were excluded due to renal pathologies, combined open surgical procedures, and administration of inotropic drugs. Hemodynamic parameters and rSrO2 were recorded in laparoscopy (n = 20) and laparotomy (n = 20) groups before induction and with 5 min intervals up to 60 min and at post-extubation.

RESULTS

Decrease in right renal rSrO2 at 45th and 60th min and 30th, 45th and 60th min in left were significant in the laparoscopy group compared to laparotomy group. In the laparoscopy group, reductions at T25, T30, T45, and T60 were significant in both renal rSrO2. Renal rSO2 increased to normal with desufflation.

CONCLUSION

IAP with pneumoperitoneum may lead to renal hypoxia in children. Renal rSO2 returns to normal with desufflation. Renal NIRS monitorization might be needed in patients with renal parenchymal and vascular pathologies, solitary kidney, and multiorgan pathologies that may affect renal oxygenation.

Scintigraphic Evaluation of the Impact of Pneumoperitoneum on Renal Blood Flow: A Rabbit Model

Background: Increased intra-abdominal pressure resulting from pneumoperitoneum can cause renal physiological changes, such as oliguria and anuria, in mammals. Although videolaparoscopic operations are common, the occurrence of renal lesions due to these procedures has not been precisely documented in the literature. The aim of this study was to evaluate the impact of pneumoperitoneum on renal blood flow using renal scintigraphy in a rabbit model. Methods: Six New Zealand male rabbits weighing 3 kg, previously anesthetized, were mechanically ventilated and underwent pneumoperitoneum. Each animal served as its own control and was analyzed in two different moments: [99mTc] diethylenetriaminepentaacetic acid (DTPA) renal blood flow evaluation in baseline conditions (T0) and 30 minutes after installation of 15 mmHg-pneumoperitoneum (T1). The animals were monitored throughout the study by capnography, oximetry, and arterial pressure median, and were euthanized at the end of the experiment. Results: The quantitative analysis of the scintigraphic images of renal uptake of the radiopharmaceutical evidence reduced renal arterial blood flow during pneumoperitoneum. Compared with baseline conditions, all animals presented a reduction of renal blood flow varying from 16% to 82%, with mean [±standard deviation] of 53% [±24%]. Conclusions: Pneumoperitoneum induces a significant reduction of the renal blood flow, as determined in this experimental method in rabbits and dynamic renal scintigraphy with [99mTc] DTPA is an adequate method to investigate this event in the experimental setting.

Changes in cerebral and renal oxygenation during laparoscopic pyloromyotomy

Although a laparoscopic approach may be preferred over open procedures for abdominal surgery, there are limited data on the effect of laparoscopic procedures on cerebral and renal oxygenation in neonates and young infants. Here, we evaluated the effect in neonates and infants. In this two-center prospective observational study, we evaluated changes in cerebral and renal regional oxygen saturation (rSO₂) in infants during laparoscopic pyloromyotomy. Intraoperative hemodynamic and respiratory parameters and rSO₂ were recorded. For the primary outcome, these parameters were compared at incision and at the end of pneumoperitoneum. The study cohort included 25 infants with a mean age of 40 ± 10 days and weight of 4.0 ± 0.6 kg. IAP at the beginning of laparoscopy was 10 ± 2 mmHg (range 7-15 mmHg). Although both cerebral and renal rSO₂ decreased from incision compared to the end of laparoscopy, the decrease reached statistical significance only for cerebral rSO₂ (81 ± 12 to 76 ± 16, p = 0.033). Similarly, the increase in fractional tissue oxygen extraction (FTOE) was only statistically significant for cerebral FTOE (0.18 ± 0.12 to 0.23 ± 0.16, p = 0.037). No change in hemodynamic or respiratory parameters was found. Although there was a decrease in cerebral rSO₂ and increase in cerebral FTOE during pneumoperitoneum, the values did not decrease below those noted before anesthetic induction.

Robotic-Assisted Urologic Surgery in Infants: Positioning, Trocar Placement, and Physiological Considerations

Pediatric robotic-assisted laparoscopic procedures are becoming increasingly common. They have been shown to be safe in younger patients, including infants. Successful adoption of robotic-assisted surgery in infants requires an understanding of the technical factors unique to this patient population. This review will delineate the specific considerations to safely perform robotic-assisted laparoscopic procedures in infants, including physiological changes associated with pneumoperitoneum in infants, positioning, trocar placement, and docking.

Update on perioperative acute kidney injury

PURPOSE OF REVIEW

In this review, we discuss the latest updates on perioperative acute kidney injury (AKI) and the specific considerations that are relevant to different surgeries and patient populations.

RECENT FINDINGS

AKI diagnosis is constantly evolving. New biomarkers detect AKI early and shed a light on the possible cause of AKI. Hypotension, even for a short duration, is associated with perioperative AKI. The debate on the deleterious effects of chloride-rich solutions is still far from conclusion. Remote ischemic preconditioning is showing promising results in the possible prevention of perioperative AKI. No definite data show a beneficiary effect of statins, fenoldepam, or sodium bicarbonate in preventing AKI.

SUMMARY

Perioperative AKI is prevalent and associated with significant morbidity and mortality. Considering the lack of effective preventive or therapeutic interventions, this review focuses on perioperative AKI: measures for early diagnosis, defining risks and possible mechanisms, and summarizing current knowledge for intraoperative fluid and hemodynamic management to reduce risk of AKI.

Arterioportal shunting, splanchnic capillary perfusion, and the effects of colloids during capnoperitoneum in neonatal and adolescent pigs

BACKGROUND

Clinical and experimental data indicate that neonates are sensitive to the CO₂ pneumoperitoneum. An impaired splanchnic perfusion during laparoscopy in adults has been reported. We recently confirmed that intravenous colloids improve macrocirculatory function in neonates. We aimed to determine the impact of CO₂ pneumoperitoneum on the perfusion of splanchnic organs in the young including effects of colloid application.

METHODS

Male piglets (n = 25) were divided into four groups: (1) neonatal controls, (2) neonates with crystalloid restitution, (3) neonates with colloidal restitution, and (4) adolescents with crystalloid restitution. Animals were ventilated and subjected to a 3-h, 10 mmHg CO₂ pneumoperitoneum followed by 2 h resuscitation. Hepatic, splanchnic, and arteriovenous shunt perfusion was assessed via central and portal venous catheters. Capillary organ flow was detected by fluorescent microspheres. The rate of bile flow was measured.

RESULTS

The neonatal crystalloid group showed a significant decrease in the intestinal capillary perfusion at the end of the recovery period. This was not detectable in the adolescent and colloid group. There was a significant increase in microcirculatory arterioportal shunt flow during the CO₂ pneumoperitoneum in both neonatal groups but not in the sham and adolescent groups (p < 0.05). Hepatic arterial perfusion increased after insufflation in all groups and dropped during capnoperitoneum to levels of about 70% baseline. There was no significant impairment of splanchnic perfusion or bile flow as a result of the pneumoperitoneum in all groups.

CONCLUSIONS

Capillary perfusion of the abdominal organs was stable during capnoperitoneum and recovery in adolescents and neonates with colloid restitution, but not with crystalloid restitution. Significant arterioportal shunting during capnoperitoneum could affect hepatic microcirculation in neonates. Our data confirm that moderate pressure capnoperitoneum has no major effect on the perfusion of abdominal organs in neonates with adequate substitution.

The effects of prolonged CO2 insufflation on kidney function in a rat pneumoperitoneum model

INTRODUCTION

Pneumoperitoneum (PP) is known to cause ischemia in kidneys and other intra-abdominal organs because of decreased splanchnic blood flow.

AIM

We aimed to determine the degree of renal injury that occurs due to a PP and prolonged PP. We measured renal injury biomarkers and made a histopathological evaluation to estimate the degree of injury and assessed the correlation of biomarkers with histopathological findings.

MATERIAL AND METHODS

Twenty-one female Sprague Dawley rats were separated randomly into three groups. Group 1 was the control group and was given anesthesia for 3 h. In group 2, a PP was administered under anesthesia for 1 h. A pneumoperitoneum was administered under anesthesia to animals in group 3 for 3 h.

RESULTS

Pathological analysis showed a significant statistical difference between the 3 groups. In particular, neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C (Cys C) levels at the 24^th h and preoperative mean urea levels showed a significant difference between the groups. The 24^th-hour NGAL level in group 3 was significantly higher than that of group 1. The preoperative Cys C level was higher in group 1 than in either group 2 or 3. Cys C was decreased significantly in group 1 and increased significantly in both groups 2 and 3.

CONCLUSIONS

The increase in NGAL and Cys C levels directly correlated with the duration of PP and intra-abdominal pressure, and they are therefore good biomarkers in diagnosing acute renal injury in the early phase. Serum creatinine level is not a good biomarker in the early phase of renal injury.

Perioperative intravenous fluid therapy in children: guidelines from the Association of the Scientific Medical Societies in Germany

This consensus- based S1 Guideline for perioperative infusion therapy in children is focused on safety and efficacy. The objective is to maintain or re-establish the child's normal physiological state (normovolemia, normal tissue perfusion, normal metabolic function, normal acid- base- electrolyte status). Therefore, the perioperative fasting times should be as short as possible to prevent patient discomfort, dehydration, and ketoacidosis. A physiologically composed balanced isotonic electrolyte solution (BS) with 1-2.5% glucose is recommended for the intraoperative background infusion to maintain normal glucose concentrations and to avoid hyponatremia, hyperchloremia, and lipolysis. Additional BS without glucose can be used in patients with circulatory instability until the desired effect is achieved. The additional use of colloids (albumin, gelatin, hydroxyethyl starch) is recommended to recover normovolemia and to avoid fluid overload when crystalloids alone are not sufficient and blood products are not indicated. Monitoring should be extended in cases with major surgery, and autotransfusion maneuvers should be performed to assess fluid responsiveness.

Pneumoperitoneum and hemodynamic stability during pediatric laparoscopic appendectomy

BACKGROUND

Conventional pneumoperitoneum (CP) and automatically maintained pneumoperitoneum using AirSeal Intelligent Flow System (AiFS) were compared during pediatric laparoscopic appendectomy (LA) using intraperitoneal pressure (IPP) and hemodynamic parameters.

METHODS

A prospective review of 39 children aged 3-14years who had standard 3-trocar LA was performed. Pneumoperitoneum was either AiFS (n=18) or CP (n=21) according to the surgeon's preference. IPP during insertion of trocars in all subjects was initially 8-10mmHg, which was reduced to 5mmHg then maintained until LA was completed. Data were collected every 5min during pneumoperitoneum.

RESULTS

Subject demographics were similar for both groups. During pneumoperitoneum, average IPP (AiFS: 7.9; CP: 9.0mmHg), average systolic blood pressure (AiFS: 100.4; CP: 106.9mmHg), and average end-tidal CO₂ (EtCO₂; AiFS: 35.7; CP: 38.5mmHg) were significantly different (p<.05, respectively), while pulse (AiFS: 92.1; CP: 96.4bpm), oxygen saturation (AiFS: 98.8; CP: 98.8%), body temperature (AiFS: 37.2; CP: 37.4), urine output (AiFS: 2.7; CP: 2.4mL/kg per hour), operative time (AiFS: 72.2; CP: 76.2mins), blood loss (AiFS: 3.6; CP: 3.5mL), recommencement of oral intake (AiFS: 1.3; CP: 1.4days), and postoperative hospitalization (AiFS: 4.3; CP: 3.8days) were not.

CONCLUSION

Because IPP was significantly lower during LA with AiFS, EtCO₂ and BP were significantly lower.

LEVEL OF EVIDENCE

Treatment study; prospective comparative study - level II.

Risk factors and preventive measures for acute urinary retention after rectal cancer surgery

BACKGROUND

Although several risk factors for acute urinary retention after rectal cancer surgery have been proposed, few studies have enrolled a homogeneous group of patients without preoperative urinary dysfunction. We aimed to identify risk factors and preventive measures for acute urinary retention after rectal cancer surgery.

METHODS

This study was a retrospective review of prospectively collected data from included patients who underwent rectal cancer surgery at a single center. Preoperative urinary function was evaluated using the International Prostate Symptom Score (IPSS). Clinical data were collected prospectively and analyzed to assess the risk factors for acute urinary retention, which was defined as the inability to self-void after removing the urinary catheter requiring catheterization or reinsertion of an indwelling catheter.

RESULTS

Of 352 patients with mild preoperative IPSS (0-7), 48 (13.6 %) experienced acute urinary retention. Multivariate logistic regression analysis showed that male sex (odds ratio [OR] 2.240, p = 0.039), laparoscopic operation (OR 2.421, p = 0.024), intraoperative intravenous fluid ≥ 2,000 mL (OR 3.794, p < 0.001), and urinary catheter removal on postoperative day 1 or 2 (OR 3.650, p = 0.017) were independent risk factors for acute urinary retention after rectal cancer surgery. Patients with two risk factors had a significantly higher risk of acute urinary retention than patients with none or one risk factor.

CONCLUSIONS

This study suggests the maintenance of a urinary catheter for a period longer than 2 days and intraoperative fluid restriction to prevent acute urinary retention after rectal cancer surgery.

Awake caudals and epidurals should be used more frequently in neonates and infants

The current literature provides fundamental insights regarding the neurotoxic potency of various general anesthetic drugs in neonates and small infants. Therefore, considerations to minimize the use of general anesthetic drugs in this age group are required. The use of caudal and epidural anesthesia under sedation is one possibility to minimize the use of general anesthetic drugs. A large number of surgical procedures can be managed with this anesthetic concept. Training, practical hand skills, good infrastructure, a well-defined indication, and a team approach including the entire operation room staff are the major prerequisites to implement these techniques in the daily clinical practice. This review article discusses all present aspects and possible future evolutions of caudal and epidural anesthesia under sedation.

Minimal invasive surgery in the newborn: current status and evidence

The evolution of minimally invasive surgery (MIS) in the newborn has been delayed due to the limited working space and the unique physiology. With the development of smaller instruments and advanced surgical skills, many of the initial obstacles have been overcome. MIS is currently used in specialized centers around the world with excellent feasibility. Obvious advantages include better cosmesis, less trauma, and better postoperative musculoskeletal function, in particular after thoracic procedures. However, the aim of academic studies has shifted from proving feasibility to a critical evaluation of outcome. Prospective randomized trials and high-level evidence for the benefit of endoscopic surgery are still scarce. Questions to be answered in the upcoming years will therefore include both advantages and potential disadvantages of MIS, especially in neonates. This review summarizes recent developments of MIS in neonates and the evidence for its use.

Clinical significance of elevated intraabdominal pressure during common conditions and procedures

INTRODUCTION

Pregnancy, obesity, peritoneal dialysis, pneumoperitoneum, prone position and application of positive end-expiratory pressure are associated with elevated intraabdominal pressure (IAP).

OBJECTIVE

To review the relation between these conditions and procedures, and intraabdominal hypertension (IAH) or abdominal compartment syndrome (ACS).

METHODS

Search of PubMed and Google Scholar and review of article bibliographies.

RESULTS AND CONCLUSION

Only obesity, peritoneal dialysis, and pneumoperitoneum are associated with symptoms related to IAH and these symptoms are reversible.

Inflammatory response after open and laparoscopic Nissen fundoplication in children: a randomized study

PURPOSE

It is assumed that laparoscopic surgery generally induces less inflammatory responses than open surgery. Since few studies have compared immune responses after laparoscopic and open surgery in children, we examined inflammatory markers in children randomized to open (ONF) or laparoscopic Nissen fundoplication (LNF).

METHODS

Blood samples were collected prior to surgery (D0), and on postoperative day 1 (D1) and day 2 (D2). Inflammatory markers were measured using a multiplex antibody bead kit. The postoperative levels of inflammatory markers were statistically analyzed using a linear mixed model. A P value <0.05 was considered statistically significant.

RESULTS

Twenty-nine patients randomized to ONF or LNF were included. Median age was 3.1 years (range 1.0-14.2) in the ONF group and 4.0 years (range 0.2-14.2) in the LNF group. Plasma levels of the anti-inflammatory cytokine interleukin (IL)-10 were significantly higher in the ONF group than in the LNF group postoperatively (P = 0.04). However, there were no significant differences between the groups in the levels of pro-inflammatory markers tumor necrosis factor-α, IL-6, IL-8, monocyte chemoattractant protein-1, white blood cell count, or C-reactive protein.

CONCLUSIONS

We did not find that laparoscopy induced a substantially less inflammatory response than laparotomy in children undergoing fundoplication.

Carbon dioxide insufflation causes upper urinary tract injury in the early period of an experimental vesicoureteral reflux model

PURPOSE

Ureteral reimplantation via pneumovesicum is a new aspect of vesicoureteral reflux management. We aimed to determine the effects of carbon dioxide (CO2) insufflation on the upper urinary tract in an experimental model.

MATERIALS AND METHODS

Thirty New Zealand rabbits were allocated into five groups of six rabbits each. Right ureters were cannulated for CO2 insufflation in four groups. The pressures and durations of CO2 insufflation in the respective groups were as follows: Group A (10 mm Hg, 2 h); B (12 mm Hg, 2 h); C (10 mm Hg, 4 h); and D (12 mm Hg, 4 h) and control (E). Blood gas analysis, urea and creatinine levels were measured from renal veins and aorta. Histopathological evaluation of the renal parenchyma and ureters was scored.

RESULTS

Significant histopathological changes were detected in the ipsilateral ureter and renal parenchyma exposed to CO2 insufflation, predominantly observed in groups insufflated for longer durations, p < 0.05. Blood gases drawn separately from renal veins were significantly more acidotic, and serum urea and creatinine levels were increased in all the groups, p < 0.05.

CONCLUSIONS

CO2 causes significant histopathological and biochemical changes in the early period. Long-term results are required to determine whether permanent renal injury occurs.

A prospective assessment of renal oxygenation in children undergoing laparoscopy using near-infrared spectroscopy

BACKGROUND

This study was designed to determine whether a decrease in renal oxygenation occurs during CO2 pneumoperitoneum in children with normal renal function undergoing laparoscopy.

METHODS

Near infrared spectroscopy (NIRS) probes were applied to both the lateral flank (T10-L2) and lateral cerebral area of all patients with normal renal function undergoing a laparoscopic procedure. Information was recorded in 5-s intervals for 15-min before, during, and for 15-min after pneumoperitoneum insufflation and desufflation. Simultaneously, additional hemodynamic parameters (arterial saturation, mean arterial pressure, end tidal CO2, and urine output) were recorded every 5-min. Pneumoperitoneum pressures used were: 0-1 month old, <6 mmHg; 2-12 months old, <8 mmHg; 1-2 years old, <10 mmHg, and 2-8 years old, <12 mmHg. The lowest possible pressure was used to obtain adequate vision.

RESULTS

Twenty-nine patients were enrolled in the study. Renal regional oxygen saturation (rSO2) did not decrease significantly between baseline (preinsufflation), insufflation, and desufflation of the pneumoperitoneum (p = 0.343). Meta-analysis of this data demonstrated a pooled weighted difference of -1.4 (-3.5 to 0.54), confirming no significant change. A significant increase in cerebral rSO2 occurred during the insufflation period of the CO2 pneumoperitoneum (p = 0.001). Heart rate (F = 11.05; p < 0.001) and mean arterial pressure (MAP) (F = 19.2; p < 0.001) also increased significantly during the laparoscopy. No significant correlation was identified between fluid input and urine output during the laparoscopy (r = 0.012; p = 0.953).

CONCLUSIONS

Renal hypoxia does not occur during laparoscopic surgery in children if the minimum age-appropriate intra-abdominal pressures are used. Alternative causes must account for the oliguria and anuria demonstrated in children undergoing laparoscopy.

Enthusiasm, evidence and ethics: the triple E of minimally invasive pediatric surgery

Minimally invasive techniques are applicable in more than 60% of abdominal and thoracic operations in children. Enthusiasts promoted these techniques for many years. However, level 1 evidence on advantages of minimally invasive surgery in children remains limited. Randomized controlled trials have been conducted for some types of procedures such as laparoscopic appendectomy, fundoplication, pyloromyotomy, and inguinal hernia repair. The results of these studies confirm some advantages of minimally invasive surgery, but for most types of laparoscopic and all types of thoracoscopic procedures, such data remain to be established. This article also focuses on reports on complications and disadvantages which are relevant for final conclusions and recommendations. The ethical implications of the application of new techniques in children are also discussed. On the basis of evidence based data and ethical principles, minimally invasive techniques may be appropriately used in the future.

Kidney safety during surgical pneumoperitoneum: an experimental study in rats

BACKGROUND

Elevations of intraabdominal pressure during laparoscopic procedures may lead to oliguria or anuria in mammals. Despite this, previous research has not been able to confirm an associated kidney injury. This study aimed to investigate the occurrence of an early kidney lesion secondary to surgical pneumoperitoneum in a rat model using the expression of neutrophil gelatinase-associated lipocalin (N-GAL) as a biomarker for early kidney injury.

METHODS

In this study, 20 male Sprague-Dawley rats under general anesthesia and mechanically ventilated were allocated to one of five experimental time-dependent groups: group 1 (1-h control), group 2 (1-h pneumoperitoneum), group 3 (2-h control), group 4 (2-h pneumoperitoneum), and group 5 (positive kidney injury group induced by intravenous administration of cisplatin 7.5 mg/kg). To evaluate the renal expression of N-GAL 24 h after the procedure, all the rats underwent a 2-h urine output evaluation as well as laparotomy and bilateral nephrectomy performed sequentially to investigate the presence of renal injury using immunofluorescence qualification and western blotting.

RESULTS

Urine output was reduced and N-GAL expression was increased in the animals from the cisplatin group. The animals undergoing 1- or 2-h pneumoperitoneum displayed urine output and N-GAL expression similar to that of the animals from the matching control groups.

CONCLUSIONS

Under the experimental conditions of this study, the animals with normal preoperative renal function did not show any type of acute kidney injury associated with the presence of a stabilized surgical pneumoperitoneum.

Minimally invasive surgery in the neonate

The advent of minimally invasive surgical techniques in the neonate has been delayed due to the limited working space and the unique physiology of the newborn. In the last decade, with the introduction of new instruments and techniques, many of the initial problems have been solved making minimally invasive surgery feasible for a variety of indications in the neonate and a favored approach in specialized centers around the world. Although an increasing number of reports document the feasibility of this exciting technique, data demonstrating its benefit compared to conventional surgery is limited. This review focuses on recent developments in minimally invasive surgery in neonates and the evidence for its use.

The effect of CO2 pneumovesicum on upper urinary tract

OBJECTIVE

Pneumovesicum allows minimal invasive intravesical surgeries. The possible deleterious effect of intravesical CO(2) pressure is not known. We assessed the effect of CO(2) pneumovesicum on the urinary tract and renal function.

METHODS

Pneumovesicum was established and maintained with CO(2) at 10 mm Hg in 10 sows. Cohen cross-trigonal reimplantation was carried out on the left ureter by a vesicoscopic approach. The right ureter was cannulated and served as control. CO(2) pneumovesicum was maintained for 2 hours. Color Doppler measurements of the upper urinary tract and blood sampling were carried out 30 minutes before and 2 hours after establishing pneumovesicum, and 30 minutes after releasing the pneumovesicum.

RESULTS

Compared with the preoperative values, the bilateral anteroposterior diameters of the renal pelves increased significantly after 2 hours of the pneumovesicum (P < .05). Thirty minutes after release of the pneumovesicum, the anteroposterior diameters decreased and showed no statistically significant difference compared with the preoperative values. No air embolus was detected in the ureters, renal pelves, renal veins, or renal arteries on either side 2 hours after establishing the pneumovesicum. There was no statistically significant change in arterial or venous blood flow. There was no significant change in the urea and creatinine levels 2 hours after establishing the pneumovesicum.

CONCLUSION

CO(2) pneumovesicum at a pressure of 10 mm Hg for 2 hours did not result in any demonstrable deleterious effect.

[Minimally invasive pediatric surgery]

In recent years minimally invasive surgical techniques in children have made substantial progress. The feasibility and safety of a wide spectrum of laparoscopic and thoracoscopic procedures have been confirmed in numerous studies. Moreover, it was reported that minimally invasive pediatric surgery is associated with lower morbidity, a shorter hospital stay, lower costs, better cosmetics and clinical results similar to those achieved by open surgery. The present article reviews information on established as well as feasible but not yet established surgical procedures. The discussion of potential hemodynamic, respiratory and organ perfusion effects of the CO(2) pneumoperitoneum and the notation of special logistic aspects should support the reader in the process of decision-making to schedule infants and children for minimally invasive surgery.

Plasma volume replacement with HES 130/0.42 obviates negative side effects of pneumoperitoneum in piglets

BACKGROUND

Evidence-based guidelines on optimal perioperative fluid management in infants have not been established. Recent randomized trials in major abdominal surgery in adults suggest that large volumes of fluid may increase morbidity and hospital stay. Our own clinical experience in infants undergoing laparoscopic surgery is different. So the aim of this study was to compare a crystalloid vs a plasma volume stabilizing fluid management regime during prolonged pneumoperitoneum (PP) in an experimental setting.

METHODS

Fifteen German landrace piglets were randomized to one of the following treatment groups: control (no PP, 5 ml x kg(-1) x h(-1) electrolyte solution); crystalloid (180 min of PP, 5 ml x kg(-1) x h(-1) electrolyte solution); colloid (180 min of PP, single bolus of 5 ml x kg(-1) followed by 5 ml x kg(-1) x h(-1) hydroxyethyl starch 130/0.42/6:2). After decompression, monitoring was continued for a further 120 min. During the investigation, the hemodynamic situation including transpulmonary thermodilution and blood gases was monitored periodically.

RESULTS

During the study, mean arterial pressure remained within the normal range in colloid-treated animals and controls, but was significantly lower in crystalloid-treated animals after decompression of PP. Cardiac output remained within the normal range in the colloid and control groups, but decreased in the crystalloid-treated animals. In the crystalloid group, the lactate concentrations were higher and base excess was lower than in the colloid and control groups at 240 and 300 min (study end).

CONCLUSION

This study shows that the negative effects of prolonged PP on hemodynamics and acid-base balance can be obviated by a liberal plasma volume stabilization regimen with colloids.

The role of laparoscopic surgery for urinary tract reconstruction in infants weighing less than 10 kg: a comparison with open surgery

PURPOSE

To compare the outcome of laparoscopic urinary tract reconstruction (LUTR) in children weighing 10 kg or less with a weight-matched cohort undergoing open urinary tract reconstruction surgery (OUTR).

MATERIALS AND METHODS

We conducted a retrospective chart review of patients weighing 10 kg or less at the time of surgery who underwent open or laparoscopic pyeloplasty, transuretero-ureterostomy and ipsilateral uretero-ureterostomy between January 2000 and May 2007. The following information was recorded: body weight, age, sex, diagnosis, type of procedure, operative time, estimated blood loss, pre- and postoperative hemoglobin levels, length of hospitalization, length of follow up, use of drains and stents, intraoperative and postoperative analgesic requirement, need for readmission, subsequent procedures, costs, complications and reoperations.

RESULTS

There were 52 patients divided into two groups: LUTR (n=23) and OUTR (n=29). Median weight (range) and follow up was 6.2 kg (3.9-10) and 9 months and 6.5 kg (4.7-9.6) and 31 months for LUTR and OUTR, respectively. Mean operative time for LUTR (including cystoscopy and stent placement) was 237 min and for OUTR 128 min (P<0.01). There were no differences in blood loss, intra- or postoperative analgesic requirement, results or complications. Mean hospitalization time was shorter for LUTR than OUTR (2 and 3 days, respectively). There were no differences in hospital costs between the two groups.

CONCLUSIONS

Laparoscopic reconstructive surgery for congenital urological anomalies is safe and effective in small infants and can be performed with outcomes comparable to that of open surgery.

Physiological responses to endoscopic surgery in children

The knowledge on the physiological impact of endoscopic surgery in infants and children is limited. Cardiovascular effects of pneumoperitoneum are mainly the result of an increase in intraabdominal pressure, absorption of carbon dioxide, and a stimulation of the neurohumoral vasoactive system. In infants, pneumoperitoneum alters the heart rate, mean arterial pressure, left ventricular endsystolic and end-diastolic volume, and meridional wall stress. Urine production is significantly reduced, and cerebral oxygenation and blood flow are altered. However, postoperative immune function is preserved or restored faster, and specific physiological responses to endoscopic surgery are well tolerated by otherwise healthy infants and children. The effects in children with specific conditions, such as sepsis, cancer, or organ dysfunction, remain to be investigated.

Acute changes in renal function after laparoscopic gastric surgery for morbid obesity

BACKGROUND

Acute renal failure (ARF) is a serious complication that contributes to patient morbidity and may result in death. To date, no data are available regarding the predictive risk of ARF or its effect on the outcome of patients who undergo laparoscopic gastric bypass.

METHODS

The medical records of 1800 patients who underwent gastric bypass from July 1997 to July 2003 at a single institution were analyzed. The data collected included demographics, comorbid factors, operative details, and postoperative outcomes. Multivariant analysis was performed and the results were compared with those of 500 age-, gender-, and comorbidity-matched control patients who underwent similar operations.

RESULTS

The mean age was 50 +/- 8 years; 23 were men and 19 were women. Of the 1800 patients, 42 (2.3%) developed ARF after surgery. Dialysis was required in 6 patients, 2 of whom became dialysis dependent. ARF completely resolved in the remaining patients.

CONCLUSION

Primary ARF after laparoscopic gastric bypass is an uncommon complication, with an incidence of 2.3% in our institution. Patients with a body mass index >50, previous chronic renal failure, and long operating times and intraoperative hypotension are at the greatest risk of postoperative renal failure. All patients who had normal renal function preoperatively returned to normal renal function within 6 months.