The complications and the position of the Codman MicroSensor™ ICP device: an analysis of 549 patients and 650 Sensors

Background

Complications of and insertion depth of the Codman MicroSensor ICP monitoring device (CMS) is not well studied.

Objective

To study complications and the insertion depth of the CMS in a clinical setting.

Methods

We identified all patients who had their intracranial pressure (ICP) monitored using a CMS device between 2002 and 2010. The medical records and post implantation computed tomography (CT) scans were analyzed for occurrence of infection, hemorrhage and insertion depth.

Results

In all, 549 patients were monitored using 650 CMS. Mean monitoring time was 7.0?±?4.9 days. The mean implantation depth was 21.3?±?11.1 mm (0–88 mm). In 27 of the patients, a haematoma was identified; 26 of these were less than 1 ml, and one was 8 ml. No clinically significant bleeding was found. There was no statistically significant increase in the number of hemorrhages in presumed coagulopathic patients. The infection rate was 0.6 % and the calculated infection rate per 1,000 catheter days was 0.8.

Conclusion

The risk for hemorrhagic and infectious complications when using the CMS for ICP monitoring is low. The depth of insertion varies considerably and should be taken into account if patients are treated with head elevation, since the pressure is measured at the tip of the sensor. To meet the need for ICP monitoring, an intraparenchymal ICP monitoring device should be preferred to the use of an external ventricular drainage (EVD).     

Automated intracranial pressure-controlled cerebrospinal fluid external drainage with LiquoGuard®

Introduction

LiquoGuard is a new device for intracranial pressure (ICP)-controlled drainage of cerebrospinal fluid (CSF). This present study evaluates the accuracy of ICP measurement via the LiquoGuard device in comparison with Spiegelberg. Thus, we compared data ascertained from simultaneous measurement of ICP using tip-transducer and tip-sensor devices.

Material and Methods

A total of 1,764 monitoring hours in 15 patients (range, 52–219 h) were analysed. All patients received an intraventricular Spiegelberg III probe with the drainage catheter connected to the LiquoGuard system. ICP reading of both devices was performed on an hourly basis. Statistical analysis was done by applying Pearson correlation and Wilcoxon-matched pair test (p?<?0.05).

Results

Mean ICP values were 11?±?5 mmHg (Spiegelberg) and 10?±?7 mmHg (LiquoGuard); the values measured with both devices correlated well (p?=?0.001; Pearson correlation =0.349; n?=?1,764). In two of the 15 patients with slit ventricles, episodes of significant differences in measured values could be observed. Both patients suffering from slit ventricles failed to produce reliable measurement with the external transducer of the LiquoGuard.

Conclusions

LiquoGuard is a valuable new device for ICP-controlled CSF drainage. However, LiquoGuard tends to provide misleading results in slit ventricles. Thus, before these drawbacks are further analysed, the authors recommend additional ICP measurement with internal tip-sensor devices to avoid dangerous erroneous interpretation of ICP data.     

Smoking as a risk factor for intraoperative hypoxemia during one lung ventilation

Background

Smoking is associated with many intra and postoperative events, especially respiratory complications. Hypoxemia and airway damage are found to aggravate any pre-existing respiratory pathology among smokers. One lung ventilation (OLV) carries a 4–10 % risk of development of hypoxia.

Aim

The purpose of this study was to predict the incidence of hypoxemia for smokers during OLV for patients undergoing video-assisted thoracoscopic surgery (VATS).

Patients and methods

Sixty patients undergoing VATS using OLV by double lumen tube were included in this pilot cross-sectional study. These patients were divided into 2 groups, group S which included 30 heavy smoker patients (smoking more than 20 cigarettes per day for more than 20 years) and group NS which included 30 non-smoker patients. Intra and postoperative arterial oxygen tension (PaO₂), arterial carbon dioxide tension (PaCO₂), and intraoperative peak airway pressure were compared between the 2 groups.

Results

PaO₂ was significantly higher in the non-smoker group than in the smoker group, both at the start and end of OLV. It was 173 ± 68 mmHg for NS compared with 74 ± 10.8 mmHg for S at the start of OLV; at the end of OLV it was 410 ± 78 mmHg for the former and 360 ± 72 mmHg for the latter (P < 0.05).

Conclusion

From this study it can be concluded that for heavy smoker patients there was a significant reduction in arterial oxygen tension (PaO₂) in comparison with non-smokers. However, hypoxemia reported for both groups was comparable.     

Transrectal robotic natural orifice translumenal endoscopic surgery (NOTES) applied to intestinal anastomosis in a porcine intestine model

Background

Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive operation using devices such as flexible endoscopes and linear or circular staplers. Nevertheless, hand-sewn anastomosis in NOTES remains challenging. This study aimed to investigate the feasibility of transrectal robotic NOTES requiring intracorporeal small intestinal anastomosis and closure of the rectal anterior wall incision in a relevant human model.

Methods

The authors developed a flexible rectal proctoscope with a diameter of 43 mm for transrectal robotic NOTES. Small intestinal anastomosis was performed in a porcine intestinal transrectal NOTES model using two robotic arms and a camera inserted through the proctoscope and a rectal anterior wall incision. The quality of transrectal small intestinal anastomosis using the da Vinci surgical system (transrectal robotic NOTES group) was compared with that of transabdominal anastomosis using the da Vinci surgical system (transabdominal robot-assisted surgery group) and transrectal anastomosis using traditional transanal endoscopic microsurgery (TEM) instruments (TEM NOTES group). The quality of transrectal rectal anterior wall suturing in the transrectal robotic NOTES group was compared with that of the TEM NOTES group and the open surgical instruments group (open group).

Results

Robotic intracorporeal suturing was performed successfully in the porcine intestine model. During small intestinal anastomosis, burst pressure in the transrectal robotic NOTES group (67.7 ± 29.3 mmHg) was similar to that in the transabdominal robot-assisted surgery group (73.3 ± 18.2 mmHg) but significantly higher than in the TEM NOTES group (20.3 ± 24.0 mmHg; p < 0.01). During rectal anterior wall suturing, the burst pressure did not differ significantly between the transrectal robotic NOTES group (149.9 ± 81.1 mmHg) and the open group (195.0 ± 60.5 mmHg).

Conclusions

The preliminary safety and efficacy of transrectal robotic NOTES was established. Further studies are required to determine the practical feasibility of this procedure.     

Schnittstellenübergreifende Verlaufsdokumentation am Beispiel von Hypotension und Hypoxie bei schwerem SHT

Background

The risk for secondary brain injury in patients with traumatic brain injury (TBI) is significantly increased by arterial hypotension and hypoxemia. The prehospital as well as the initial inhospital management is decisive in the therapy of this lethal duo. The aim of this pilot study was to perform an expanded analysis of arterial hypotension and hypoxemia.

Methods

Retrospective analysis of routine medical data recording in patients with severe TBI (Glasgow coma scale GCS?<?9) at HEMS Ulm and further inhospital treatment at the Federal Armed Forces Medical Centre Ulm. Arterial hypotension was defined as RR_sys?≤?90 mmHg and hypoxemia as S_pO₂≤?90%.

Results

A total of 45 patients (male 67.3%, average age 43.3?±?20.0 years, injury severity score ISS: 40.8?±?27.4) were included in this pilot study. On arrival of emergency services at the scene 25.6% of the patients were in shock (RR_sys?≤?90 mmHg) and 23.3% were hypoxemic (S_pO₂?≤90%). This could be significantly reduced to 7.0% for each factor 10 min after arrival at the scene. On hospital admission only 7.0% of the patients were hypotensive and 2.3% hypoxemic. In patients where the initial inhospital resuscitation period was terminated prematurely due to life-saving surgical intervention, systolic arterial blood pressure was significantly lower during the entire inhospital resuscitation period than in patients where this period was completed regularly. Furthermore, in survivors the systolic arterial pressure was significantly higher than in non-survivors on arrival at the scene (118?±?29 mmHg vs. 86?±?32 mmHg; p?<?0.05) and at the end of the inhospital resuscitation period (125?±?19 mmHg vs. 90?±?36 mmHg; p?<?0.05).

Conclusions

The lethal duo of hypoxemia and hypotension is common in patients with associated TBI. In most patients it can adequately be treated within the first 10 min after arrival of emergency services at the scene but only patients where hypotension and hypoxemia can be avoided as the situation develops will profit regarding outcome.     

Using stress MRI to analyze the 3D changes in apical ligament geometry from rest to maximal Valsalva: a pilot study

Introduction and hypothesis

A method was developed using 3D stress magnetic resonance imaging (MRI) and was piloted to test hypotheses concerning changes in apical ligament lengths and lines of action from rest to maximal Valsalva.

Methods

Ten women with (cases) and ten without (controls) pelvic organ prolapse (POP) were selected from an ongoing case–control study. Supine, multiplanar stress MRI was performed at rest and at maximal Valsalva and was imported into 3D Slicer v. 3.4.1 and aligned. The 3D reconstructions of the uterus and vagina, cardinal ligament (CL), deep uterosacral ligament (USL_d), and pelvic bones were created. Ligament length and orientation were then measured.

Results

Adequate ligament representations were possible in all 20 study participants. When cases were compared with controls, the curve length of the CL at rest was 71 ±16 mm vs. 59?±?9 mm (p?=?0.051), and the USL_d was 38?±?16 mm vs. 36?±?11 mm (p?=?0.797). Similarly, the increase in CL length from rest to strain was 30?±?16 mm vs. 15?±?9 mm (p?=?0.033), and USL_d was 15?±?12 mm vs. 7?±?4 mm (p?=?0.094). Likewise, the change in USL_d angle was significantly different from CL (p?<?0.001).

Conclusions

This technique allows quantification of 3D geometry at rest and at strain. In our pilot sample, at maximal Valsalva, CL elongation was greater in cases than controls, whereas USL_d was not; CL also exhibited greater changes in ligament length, and USL_d exhibited greater changes in ligament inclination angle.     

Micro-ureteroscopy vs. ureteroscopy: effects of miniaturization on renal vascularization and intrapelvic pressure

Purpose

Ureteroscopy (URS) is related to complications, as fever or postoperative urinary sepsis, due to high intrapelvic pressure (IPP) during the procedure. Micro-ureteroscopy (m-URS) aims to reduce morbidity by miniaturizing the instrument. The objective of this study is to compare IPP and changes in renal haemodynamics, while performing m-URS vs. conventional URS.

Methods

A porcine model involving 14 female pigs was used in this experimental study. Two surgeons performed 7 URS (8/9.8 Fr), for 45 min, and 7 m-URS (4.85 Fr), for 60 min, representing a total of 28 procedures in 14 animals. A catheter pressure transducer measured IPP every 5 min. Haemodynamic parameters were evaluated by Doppler ultrasound. The volume of irrigation fluid employed in each procedure was also measured.

Results

The range of average pressures was 5.08–14.1 mmHg in the m-URS group and 6.08–20.64 mmHg in the URS (NS). 30 mmHg of IPP were not reached in 90% of renal units examined with m-URS, as compared to 65% of renal units in the URS group. Mean peak diastolic velocity decreased from 15.93 to 15.22 cm/s (NS) in the URS group and from 19.26 to 12.87 cm/s in the m-URS group (p < 0.01). Mean resistive index increased in both groups (p < 0.01). Irrigation fluid volume used was 485 mL in the m-URS group and 1475 mL in the URS group (p < 0.001).

Conclusions

m-URS requires less saline irrigation volumes than the conventional ureteroscopy and increases renal IPP to a lesser extent.

     

Clinical outcomes and patient satisfaction rates among elderly male aged ≥75 years with inflatable penile prosthesis implant for medically refractory erectile dysfunction

Purpose

The purpose of the study is to assess the clinical outcomes and patient satisfaction rate between men aged under and over 75 years who underwent inflatable penile prosthesis (IPP) implantation.

Methods and materials

A retrospective review of clinical database and follow-up independent telephone survey was undertaken in all men who underwent first-time IPP implantation between January 2006 and November 2010. Patient demographics, surgical outcomes, and patient satisfaction rate using Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) scores were recorded.

Results

A total of 216 first-time IPP were implanted. Of these, 30 patients were aged ≥75 years. In men aged ≥75 years, 3 patients had IPP revision surgery for mechanical malfunction (average 18.6 months; 12–24 months). While the 2-year Kaplan–Meier estimates of mechanical survival showed better outcome in men aged ≥75 years than men aged <75 years (95 vs. 92 %; p = 0.38), there was no difference in the IPP mechanical survival between the 2 groups at 3 years follow-up. There were no statistically significant differences in the ease of IPP use, and EDITS scores among the two groups. The majority of men were satisfied and would recommend the IPP surgery to other men.

Conclusions

Men aged ≥75 years reported satisfactory outcome with IPP surgery with no statistical significant difference identified across device survival and satisfaction rates compared to men aged <75 years.     

Use of the tarSys® for posterior lamellar grafting for lower eyelid malposition

Background

Lower eyelid malposition is a common clinical finding encountered by the oculoplastic surgeon. We examine the short-term results with the use of the tarSys spacer graft for the correction of lower eyelid malposition.

Methods

A retrospective chart review of one surgeon’s outcomes with use of tarSys spacer graft for lower eyelid malposition was conducted.

Results

Preoperative margin-to-reflex distance 2 (MRD2) ranged from 8 to 15 mm with a mean of 9.5 mm (±2.4 mm) and median 8.25 mm. Mean postoperative MRD2 was 6.2 (±3.4 mm) ranging from 4 to 17 mm with a median of 5.0 mm. Improvement in MRD2 averaged 3.33 (±2.07 mm), range ?2 to 6 mm, and a median of 3.25 mm. Preoperative lagophthalmos ranged from 0 to 10 mm with mean 3.9 (±3.6 mm) and a median of 3.0 mm. Mean postoperative lagophthalmos was 1.3 (±1.5 mm) ranging from 0 to 4 mm with a median of 0.7 mm. Improvement in lagophthalmos averaged 2.5 (±2.7 mm).

Conclusions

The tarSys spacer graft should be thought of as a dependable allogenic implant for posterior lamellar support when correcting lower eyelid malposition. Level of Evidence: Level V, therapeutic study.     

Methohexital zur Therapie des erh?hten intrakraniellen Drucks

Background

Barbiturate coma therapy is a useful method to control increased intracranial pressure (ICP) in patients with severe brain damage if standard measures have failed to lower ICP. Pentobarbital (not available in Germany) and thiopental (in Germany only approved for induction of anesthesia) have frequently been used in patients with intracranial hypertension and the effects and side-effects are well-described. However, little is known about the effect of methohexital (the only barbiturate in Germany approved for maintaining anesthesia) in lowering increased ICP. Therefore, the effect of methohexital on ICP was studied in patients where standard measures had failed to control intracranial hypertension.

Method

A retrospective observational study was carried out with the inclusion criteria of patient age ??18 years and methohexital therapy for 12?h or more with ICP monitoring in place. Methohexital was administered following a standardized algorithm to patients for whom standard measures, such as deep anesthesia, normoventilation, cerebral perfusion pressure (CPP) >65?mmHg, osmotherapy, neurosurgical evacuation of mass lesions, had failed to lower ICP. Methohexital was used if the ICP had risen above 20?C25?mmHg for more the 20?C30?min and otherwise manageable causes for the ICP increase had been ruled out. Methohexital was given continuously in addition to standard analgesia and sedation in doses of 2?C4?C6?mg/kg body weight (BW), depending on the ICP lowering effect. The records of the patient data management system from the years 2008/2009 were used to compare the ICP and CPP before and during methohexital administration. For statistical analyses Student??s t-test was applied for measured values and the ??²-test was applied for percentage values whereby p<0.05 was defined as being statistically significant.

Results

During the study period 36 patients required methohexital therapy and 30 fulfilled the inclusion criteria. In 26 out of 30 patients the data were complete and these 26 patients were included in the data analyses. Of the patients 6 (23%) died due to elevated intracranial hypertension and 20 patients (77%) survived. In all patients methohexital lowered the ICP from 25.2?mmHg (standard deviation, SD ±4.3?mmHg) to 19.8?mmHg (SD ±12.5?mmHg) within the first 24?h, this result closely failed to reach a level of significance. In the 20 survivors methohexital lowered the ICP from 25.88?mmHg (SD ±4.8?mmHg) to 14.25?mmHg (SD ±6.9?mmHg) within the first 24?h, which is statistically highly significant. In non-survivors the ICP had risen from 24?mmHg (SD ±2.6?mmHg) to 32?mmHg (SD ±16.3?mmHg) within the first 24?h despite all efforts. Due to the CPP driven volume and vasopressor therapy no significant changes in the CPP during methohexital administration were observed. No significant changes in brain temperature (as possible cause for the decrease of the ICP) were observed. Non-survivors received significantly more methohexital due to increased ICP and required significantly more vasopressor therapy to maintain a sufficient CPP.

Conclusions

Methohexital showed a clear trend for decreasing ICP in patients with intracranial hypertension refractory to standard therapeutic measures. In survivors the effect was highly significant. Patients not responding to methohexital therapy seemed to have an unfavorable outcome.     

Benchtop evaluation of pressure barrier insufflator and standard insufflator systems

Background

Previous experimental research has reported minimal differences in pressure maintenance between different versions of standard insufflators (SI). However, a recent report identified potential clinical benefits with a valveless pressure barrier insufflator (PBI). We sought to perform a benchtop objective evaluation of SI and PBI systems.

Methods

A rigid box system with continuous pressure manometry was used to evaluate a PBI (Surgiquest Airseal) and two SIs (SI1 = Stryker PneumoSure High Flow Insufflator and SI2 = Storz SCB Thermoflator). Pressure maintenance of 15 mmHg was evaluated during experimental conditions of leakage from a 5 mm port site, leakage from a 12 mm port site, and continuous suction.

Results

With leakage from the 5 mm port site, the PBI maintained pressure of >13 mmHg whereas the pressures dropped moderately with the SI1 (7–13 mmHg) and SI2 insufflators (3–7 mmHg) and did not regain goal pressure until leakage was stopped. With leakage from 12 mm port site, the PBI pressure decreased to 9–11 mmHg, whereas the SI1 and SI2 lost insufflation pressures completely. The PBI maintained pressure of >11 mmHg during continuous suction while the SI1 and SI2 lost pressure entirely, and actually showed negative pressure from air suction into the rigid box system. When evaluated statistically with the mixed model repeated measures ANOVA, the SI1 and SI2 performed similarly while the PBI maintained increased pressure.

Conclusions

In the experimental rigid box system, the PBI more successfully maintained pressure in response to leakage and suction than SIs.     

Early outcomes and hemodynamics after implantation of the Trifecta aortic bioprosthesis

Objective

The Trifecta valve is a recent, newly designed high performance valve, with few studies on the clinical and hemodynamic data. The purpose of this study was to evaluate the early clinical and echocardiographic results of the Trifecta valve.

Methods

Between April 2012 and December 2012, 23 consecutive patients underwent aortic valve replacement with the Trifecta valve in our institution. Clinical and hemodynamic data were prospectively recorded and hemodynamic performance was assessed by transthoracic echocardiography.

Results

Nine patients were male and the overall mean age was 75 ± 9 years. Twenty patients suffered aortic stenosis, and 3 suffered aortic insufficiency. Prosthesis sizes implanted were: 19 mm (n = 4), 21 mm (n = 12), and 23 mm (n = 7). There were no 30-day deaths and no valve-related events during follow-up, except for 1 postoperative stroke. The mean postoperative transprosthetic pressure gradient was 10.0 ± 1.4, 9.6 ± 3.6, and 7.1 ± 3.6 mmHg, and the effective orifice area was 1.45 ± 0.13, 1.68 ± 0.16, and 1.90 ± 0.28 cm², for valve sizes 19, 21, and 23 mm, respectively. One patient had moderate prosthesis–patient mismatch. No moderate to severe aortic regurgitation was observed. The mean pressure gradient in aortic stenosis patients decreased significantly from 49.9 ± 20.7 to 8.9 ± 3.6 mmHg (p < 0.001). Left ventricular mass index in all patients decreased significantly from 142.0 ± 33.6 to 115.4 ± 26.4 g/m² (p < 0.001).

Conclusions

The Trifecta aortic bioprosthesis provided satisfactory early outcomes and hemodynamic function.     

Airway pressure release ventilation during ex vivo lung perfusion attenuates injury

Objective

Critical organ shortages have resulted in ex vivo lung perfusion gaining clinical acceptance for lung evaluation and rehabilitation to expand the use of donation after circulatory death organs for lung transplantation. We hypothesized that an innovative use of airway pressure release ventilation during ex vivo lung perfusion improves lung function after transplantation.

Intraoperative Ventilation of Morbidly Obese Patients Guided by Transpulmonary Pressure

Background

Bariatric surgery has proven a successful approach in the treatment of morbid obesity and its concomitant diseases such as diabetes mellitus and arterial hypertension. Aiming for optimal management of this challenging patient cohort, tailored concepts directly guided by individual patient physiology may outperform standardized care. Implying esophageal pressure measurement and electrical impedance tomography—increasingly applied monitoring approaches to individually adjust mechanical ventilation in challenging circumstances like acute respiratory distress syndrome (ARDS) and intraabdominal hypertension—we compared our institutions standard ventilator regimen with an individually adjusted positive end expiratory pressure (PEEP) level aiming for a positive transpulmonary pressure (P _L) throughout the respiratory cycle.

Methods

After obtaining written informed consent, 37 patients scheduled for elective bariatric surgery were studied during mechanical ventilation in reverse Trendelenburg position. Before and after installation of capnoperitoneum, PEEP levels were gradually raised from a standard value of 10 cm H₂O until a P _L of 0 +/? 1 cm H₂O was reached. Changes in ventilation were monitored by electrical impedance tomography (EIT) and arterial blood gases (ABGs) were obtained at the end of surgery and 5 and 60 min after extubation, respectively.

Results

To achieve the goal of a transpulmonary pressure (P _L) of 0 cm H₂O at end expiration, PEEP levels of 16.7 cm H₂O (95% KI 15.6–18.1) before and 23.8 cm H₂O (95% KI 19.6–40.4) during capnoperitoneum were necessary. EIT measurements confirmed an optimal PEEP level between 10 and 15 cm H₂O before and 20 and 25 cm H₂O during capnoperitoneum, respectively. Intra- and postoperative oxygenation did not change significantly.

Conclusion

Patients during laparoscopic bariatric surgery require high levels of PEEP to maintain a positive transpulmonary pressure throughout the respiratory cycle. EIT monitoring allows for non-invasive monitoring of increasing PEEP demand during capnoperitoneum. Individually adjusted PEEP levels did not result in improved postoperative oxygenation.

     

Biocompatible heterogeneous porous gel matrix NeuroGelTM promotes regeneration of rat sciatic nerve within tubular silicone prosthesis (experimental study)

Background

The purpose of this study was to investigate the ability of NeuroGel? to promote and enhance the regeneration of rat sciatic nerve within a 10-mm gap using silicone tubular prosthesis, and to evaluate and compare the regeneration outcomes versus autologous grafting.

Methods

The 10-mm gap of rat sciatic nerve was bridged through silicone tubular prosthesis filled with dehydrated NeuroGel?, and NeuroGel? saturated with rat NGF-B (NG30-NGG60, NGgfB30-NGgfB60). To assess the regeneration of the peripheral nerve we utilized three general and most commonly applied methods: electrophysiologic, hystomorphometric, and functional methods.

Results

The average M-wave amplitude (A_MW index), or the intermediary index of the number of regenerated axons, in animal groups NGG60 and NGgfB60 60 days post-op was: 2.44?±?0.57 mV and 1.87?±?0.48 mV. These indices were statistically lower compared to the indices obtained after autologous grafting. The average impulse conduction velocity along motor fibers (V_MF index), or the intermediary index of myelination rate, was: 13.3 mm/ms and 13.3 mm/ms, respectively, statistically equal to indices obtained after autologous grafting. The average density (D) of regenerated fibers (direct numerical indicator in contrast to intermediary A_MW index) in animal groups NGG60 and NGgfB60 was: 4,920?±?178.88 and 5,340?±?150.33 per mm², respectively. These indices were statistically higher versus indices obtained after autologous grafting. Myelination rates of regenerated fibers in animal groups NGG60 and NGgfB60 were 73 and 86 %, respectively. They were also statistically higher. The average sciatic functional index (SFI) in NGG60 and NGgfB60 was: ?25.57?±?3.05 and ?24.124?±?4.8, respectively, which is statistically equal to indices obtained after autologous grafting.

Conclusions

Neurogel? strongly promotes the regeneration of rat sciatic nerve within silicone tubular prosthesis. After bridging a 10-mm gap through silicone prosthesis with Neurogel? or Neurogel? +NGF-B-modified intraluminal space, the myelination rate of regenerated axons of rat sciatic nerve appeared to be higher, and the axon count and functional recovery is similar to results seen with the autografting technique.     

Effects of the closing speed of stapler jaws on bovine pancreases

Background

The division of the pancreatic parenchyma using a stapler is important in pancreatic surgery, especially for laparoscopic surgery. However, this procedure has not yet been standardized.

Methods

We analyzed the effects of the closing speed of stapler jaws using bovine pancreases for each method. Furthermore, we assigned 10 min to the slow compression method, 5 min to the medium-fast compression method, and 30 s to the rapid compression (RC) method. The time allotted to holding (3 min) and dividing (30 s) was equal under each testing situation.

Results

We found that the RC method showed a high-pressure tolerance compared with the other two groups (rapid, 126 ± 49.0 mmHg; medium-fast, 55.5 ± 25.8 mmHg; slow, 45.0 ± 15.7 mmHg; p < 0.01), although the histological findings of the cut end were similar. The histological findings of the pancreatic capsule and parenchyma after the compression by staple jaws without firing also were similar.

Conclusions

RC may provide an advantage as measured by pressure tolerance. A small series of distal pancreatectomy with a stapler that compares the speed of different stapler jaw closing times is required to prove the feasibility of these results after the confirmation of the advantages of the RC method under various settings.     

The intracranial volume pressure response in increased intracranial pressure patients: Part 1. Calculation of the volume pressure indicator

Background

The intracranial pressure (ICP) is usually continuously monitored in the management of patients with increased ICP. The aim of this study was to discover a mathematic equation to express the intracranial pressure–volume (P–V) curve and a single indicator to reflect the status of the curve.

Methods

Patients with severe brain damage who had bilateral external ventricular drainage (EVD) from December 2008 to February 2010 were included in this study. The EVD was used as drainage of CSF and ICP monitor. The successive volume pressure response [6] values were obtained by successive drainage of CSF from ICP 20–25 to 10?mmHg. Parabolic, exponential, and linear regression models were designed to have a single parameter as the indicator to determine the P–V curves.

Results

The mean of parameter “a” in the exponential equation is 1.473?±?0.054; in the parabolic equation, it is 0.332?±?0.061; and in the linear equation, it is 1.717?±?0.209. All regression equations of P–V curves had statistical significance (p?<?0.005). Parabolic and exponential equations are closer to the original ICP curve than linear equation (p?<?0.005). There is no statistically significant difference between parabolic and exponential regressions.

Conclusions

The P–V curve can be expressed with linear, parabolic, and exponential regression models in increased ICP patients. The parabolic and exponential equations are more accurate methods to represent the P–V curve. The single parameter in the three regression equations can be compared in different conditions of one patient in clinical practice.