A Multicenter Analysis of the Early Impact of COVID-19 on Junior Resident Operative Case Volume.

INTRODUCTION: Institutions have reported decreases in operative volume due to COVID-19. Junior residents have fewer opportunities for operative experience and COVID-19 further jeopardizes their operative exposure. This study quantifies the impact of the COVID-19 pandemic on resident operative exposure using resident case logs focusing on junior residents and categorizes the response of surgical residency programs to the COVID-19 pandemic. MATERIALS AND METHODS: A retrospective multicenter cohort study was conducted; 276,481 case logs were collected from 407 general surgery residents of 18 participating institutions, spanning 2016-2020. Characteristics of each institution and program changes in response to COVID-19 were collected via surveys. RESULTS: Senior residents performed 117 more cases than junior residents each year (P < 0.001). Prior to the pandemic, senior resident case volume increased each year (38 per year, 95% confidence interval 2.9-74.9) while junior resident case volume remained stagnant (95% confidence interval 13.7-22.0). Early in the COVID-19 pandemic, junior residents reported on average 11% fewer cases when compared to the three prior academic years (P = 0.001). The largest decreases in cases were those with higher resident autonomy (Surgeon Jr, P = 0.03). The greatest impact of COVID-19 on junior resident case volume was in community-based medical centers (246 prepandemic versus 216 during pandemic, P = 0.009) and institutions which reached Stage 3 Program Pandemic Status (P = 0.01). CONCLUSIONS: Residents reported a significant decrease in operative volume during the 2019 academic year, disproportionately impacting junior residents. The long-term consequences of COVID-19 on junior surgical trainee competence and ability to reach cases requirements are yet unknown but are unlikely to be negligible.

A systematic review and meta-analysis of predictors of recurrence in patients with Solid Pseudopapillary Tumors of the Pancreas.

BACKGROUND: The recurrence rates and predictors of recurrence in patients with Solid Pseudopapillary tumors (SPT) are unclear, which makes it challenging to determine the duration of follow-up. The aim of the current study was to perform a systematic review and meta-analysis to determine the recurrence rates and pathologic factors associated with recurrence in patients with SPT. METHODS: A PubMed, Scopus, and Web of Science search was conducted to identify studies of SPT published during the last 15 years: (09/2002-09/2017). Studies reporting on patients with SPT and follow-up of >5 years were included. The search strategy was conducted per 2009 PRISMA guidelines. RESULTS: A total of 103 studies reporting on 2599 non-metastatic SPT patients were identified. Sixty-nine patients (2.6%) developed recurrence during follow-up. Pooled estimates from studies with a sample size >20 (N = 33) noted an overall recurrence rate of 2% (95% CI 1-2%). Male gender (OR 1.960), positive lymph nodes (OR 11.9), R1 margins (OR 11.1), and LVI (OR 5.5), were associated with a significantly (all p < 0.05) increased risk of recurrence. CONCLUSION: Current meta-analysis suggests that only 2% of patients with SPT experience recurrence after resection. These data will guide the treating physicians and patients regarding recurrence rates and help identify patients at increased risk of recurrence during follow-up.

Readiness of US General Surgery Residents for Independent Practice.

OBJECTIVE: This study evaluates the current state of the General Surgery (GS) residency training model by investigating resident operative performance and autonomy. BACKGROUND: The American Board of Surgery has designated 132 procedures as being "Core" to the practice of GS. GS residents are expected to be able to safely and independently perform those procedures by the time they graduate. There is growing concern that not all residents achieve that standard. Lack of operative autonomy may play a role. METHODS: Attendings in 14 General Surgery programs were trained to use a) the 5-level System for Improving and Measuring Procedural Learning (SIMPL) Performance scale to assess resident readiness for independent practice and b) the 4-level Zwisch scale to assess the level of guidance (ie, autonomy) they provided to residents during specific procedures. Ratings were collected immediately after cases that involved a categorical GS resident. Data were analyzed using descriptive statistics and supplemented with Bayesian ordinal model-based estimation. RESULTS: A total of 444 attending surgeons rated 536 categorical residents after 10,130 procedures. Performance: from the first to the last year of training, the proportion of Performance ratings for Core procedures (n = 6931) at "Practice Ready" or above increased from 12.3% to 77.1%. The predicted probability that a typical trainee would be rated as Competent after performing an average Core procedure on an average complexity patient during the last week of residency training is 90.5% (95% CI: 85.7%-94%). This falls to 84.6% for more complex patients and to less than 80% for more difficult Core procedures. Autonomy: for all procedures, the proportion of Zwisch ratings indicating meaningful autonomy ("Passive Help" or "Supervision Only") increased from 15.1% to 65.7% from the first to the last year of training. For the Core procedures performed by residents in their final 6 months of training (cholecystectomy, inguinal/femoral hernia repair, appendectomy, ventral hernia repair, and partial colectomy), the proportion of Zwisch ratings (n = 357) indicating near-independence ("Supervision Only") was 33.3%. CONCLUSIONS: US General Surgery residents are not universally ready to independently perform Core procedures by the time they complete residency training. Progressive resident autonomy is also limited. It is unknown if the amount of autonomy residents do achieve is sufficient to ensure readiness for the entire spectrum of independent practice.

Team training for surgical trainees.

Healthcare professionals work in teams but are rarely trained together. Realizing the adverse impact of poor teamwork on patient care, the Accreditation Council for Graduate Medical Education requires surgical trainees to demonstrate a mastery of teamwork-related competencies. A number of team training curricula are available in the USA, the best known of which is TeamSTEPPS - developed by the U.S. Department of Defense Patient Safety Program in collaboration with the Agency for Healthcare Research and Quality.

Complications and treatment failures of video-assisted thoracoscopic debridement for pediatric empyema.

PURPOSE: Video-assisted thoracoscopic debridement (VATD) is a well-established intervention to treat pediatric empyema. There is ongoing controversy at what stage in the treatment algorithm it should be utilized. To shed further light onto this debate, we reviewed our institutional experience looking for factors predicting treatment failure or complications of VATD. METHODS: We retrospectively analyzed data on patients that had undergone VATD for empyema from 1995 to 2008. We used independent sample t tests and Chi-square tests (SPSS) for statistical analysis. RESULTS: One hundred and fifty-two procedures in 151 patients [81 male (53.6%)] were identified. In 146 (96.7%) the etiology of the empyema was pulmonary, in 3 (1.98%) due to an infectious abdominal process and in 2 (1.3%) due to abdominal trauma. 118 patients (78.1%) were transferred from outside hospitals. 107 (70.1%) underwent VATD primarily, 44 (29.1%) following another procedure. The overall complication rate was 13.8%, most of which were minor. Treatment failures occurred in seven patients, resulting in three reoperations; two patients died. The average length of stay was 10.1 days, but was significantly longer if VATD followed another procedure or if a complication occurred. The risk for complications correlated with older age (6.2 vs. 8.8 years, p = 0.023) and lower hematocrit on admission (31.1 vs. 27.9%, p = 0.006). CONCLUSIONS: VATD provided effective treatment for pediatric empyema. Complications were mostly minor, occurring more frequently in older patients and those with a lower admission hematocrit. Early VATD decreased the length of hospitalization.

Association Between Entrustable Professional Activities and Milestones Evaluations: Real-time Assessments Correlate With Semiannual Reviews.

OBJECTIVE: Entrustable professional activities (EPAs) have been developed to refine competency-based education. The American Board of Surgery has initiated a 2-year pilot study to evaluate the impact of EPAs on the evaluation and feedback of surgical residents. The ACGME Milestones in Surgery is a semiannual competency-based evaluation program to measure resident progression through 16 professional attributes across 8 practice domains. The correlation between these 2 evaluation tools remains unclear. The purpose of this study is to evaluate this correlation through comparison of an EPA with the corresponding elements of the ACGME Milestones. DESIGN: From July, 2018 to October, 2019, all residents submitting EPA evaluations for gall bladder disease were evaluated for preoperative, intraoperative, and/or postoperative entrustability. The ratings were converted to a numerical rank from 0 to 4. Milestones scores from May 2019 and November 2019 were obtained for each resident, with scores ranging from 0 to 4. The gall bladder EPA incorporates the operative PC3 and MK2 and nonoperative PC1, PC2, and ICS3 components. Spearman rank correlation was conducted to evaluate the association between each resident's median EPA ranking and his/her milestones scores. SETTING: SUNY Upstate Medical University, Syracuse, NY, a university-based hospital. PARTICIPANTS: General surgery residents. RESULTS: Among 24 residents, 106 intraoperative EPA evaluations were. For both the May and November milestones, significant positive correlations were noted for PC3 (correlation coefficient ρ = 0.690, p < 0.001; ρ = 0.876, p < 0.001). Similarly, for MK2, a significant positive correlation was noted (ρ = 0.882, p < 0.001; ρ = 0.759, p < 0.001). Interestingly, significant positive correlations were also identified between the 3 nonoperative milestones and the intraoperative entrustability ranking. CONCLUSIONS: We observed significant correlations between EPAs for cholecystectomy and associated milestones evaluation scores. These findings indicate that EPAs may provide more timely and specific feedback than existing tools and, on aggregate, may improve upon existing formative feedback practices provided through the biannual evaluation of surgical residents.

Beyond the Surgical Time-Out: A National Needs Assessment of Preoperative Communication in US General Surgery Residency Programs.

OBJECTIVE: Perioperative communication is critical for procedural learning. In order to develop a periprocedural faculty development tool, we aimed to characterize the current status of preoperative communication in US General Surgery residency programs. DESIGN: After Association of Program Directors in Surgery approval, a survey was distributed to general surgery programs. Participants were asked about perioperative communication, including the frequency of preoperative briefings, defined as dedicated educational discussions prior to a procedure. Data were analyzed using descriptive statistics. SETTING: An anonymous electronic survey was distributed to interested programs in early 2019. PARTICIPANTS: US General Surgery trainees and attending surgeons. RESULTS: A total of 348 responses were recorded from 27 programs: 199 (57%) attending surgeons and 149 (43%) surgical trainees. Most respondents (83%) were from a university-affiliated program. Attending surgeons indicated a higher frequency of performing preoperative briefings compared to trainees (p < 0.001). Both trainees and attending surgeons were more likely to select their own group when asked who initiates a preoperative briefing. The majority of respondents (58%) agreed that discussing autonomy preoperatively improves resident autonomy for the case. In regards to the timing of preoperative briefings, most took place in/adjacent to the operating room, with only 60 participants (17%) participating in preoperative briefings the day/night prior to the operation. The most frequent topic discussed during preoperative briefings was "procedural content." Most participants selected "time constraints" as the greatest barrier to preoperative briefings and indicated that attending surgeon engagement was necessary to facilitate their use. Trainees were less likely to report engaging in immediate postoperative feedback, but more likely to report postoperative self-reflection. CONCLUSIONS: Preoperative briefings are not necessarily routine and attendings and trainees differ on their perceptions related to their content and frequency. Efforts to address timing and scheduling and encourage dual-party engagement in perioperative communication are key to the development of tools to enhance this important aspect of procedural learning.

Concordance Between Expert and Nonexpert Ratings of Condensed Video-Based Trainee Operative Performance Assessment.

OBJECTIVE: We examined the impact of video editing and rater expertise in surgical resident evaluation on operative performance ratings of surgical trainees. DESIGN: Randomized independent review of intraoperative video. SETTING: Operative video was captured at a single, tertiary hospital in Boston, MA. PARTICIPANTS: Six common general surgery procedures were video recorded of 6 attending-trainee dyads. Full-length and condensed versions (n = 12 videos) were then reviewed by 13 independent surgeon raters (5 evaluation experts, 8 nonexperts) using a crossed design. Trainee performance was rated using the Operative Performance Rating Scale, System for Improving and Measuring Procedural Learning (SIMPL) Performance scale, the Zwisch scale, and ten Cate scale. These ratings were then standardized before being compared using Bayesian mixed models with raters and videos treated as random effects. RESULTS: Editing had no effect on the Operative Performance Rating Scale Overall Performance (-0.10, p = 0.30), SIMPL Performance (0.13, p = 0.71), Zwisch (-0.12, p = 0.27), and ten Cate scale (-0.13, p = 0.29). Additionally, rater expertise (evaluation expert vs. nonexpert) had no effect on the same scales (-0.16 (p = 0.32), 0.18 (p = 0.74), 0.25 (p = 0.81), and 0.25 (p = 0.17). CONCLUSIONS: There is little difference in operative performance assessment scores when raters use condensed videos or when raters who are not experts in surgical resident evaluation are used. Future validation studies of operative performance assessment scales may be facilitated by using nonexpert surgeon raters viewing videos condensed using a standardized protocol.

The effect of gender on operative autonomy in general surgery residents.

BACKGROUND: Despite an increasing number of women in the field of surgery, bias regarding cognitive or technical ability may continue to affect the experience of female trainees differently than their male counterparts. This study examines the differences in the degree of operative autonomy given to female compared with male general surgery trainees. METHODS: A smartphone app was used to collect evaluations of operative autonomy measured using the 4-point Zwisch scale, which describes defined steps in the progression from novice ("show and tell") to autonomous surgeon ("supervision only"). Differences in autonomy between male and female residents were compared using hierarchical logistic regression analysis. RESULTS: A total of 412 residents and 524 faculty from 14 general surgery training programs evaluated 8,900 cases over a 9-month period. Female residents received less autonomy from faculty than did male residents overall (P < .001). Resident level of training and case complexity were the strongest predictors of autonomy. Even after controlling for potential confounding factors, including level of training, intrinsic procedural difficulty, patient-related case complexity, faculty sex, and training program environment, female residents still received less operative autonomy than their male counterparts. The greatest discrepancy was in the fourth year of training. CONCLUSION: There is a sex-based difference in the autonomy granted to general surgery trainees. This gender gap may affect female residents' experience in training and possibly their preparation for practice. Strategies need to be developed to help faculty and residents work together to overcome this gender gap.

Is the operative autonomy granted to a resident consistent with operative performance quality.

BACKGROUND: We investigated attending surgeon decisions regarding resident operative autonomy, including situations where operative autonomy was discordant with performance quality. METHODS: Attending surgeons assessed operative performance and documented operative autonomy granted to residents from 14 general surgery residency programs. Concordance between performance and autonomy was defined as "practice ready performance/meaningfully autonomous" or "not practice ready/not meaningfully autonomous." Discordant circumstances were practice ready/not meaningfully autonomous or not practice ready/meaningfully autonomous. Resident training level, patient-related case complexity, procedure complexity, and procedure commonality were investigated to determine impact on autonomy. RESULTS: A total of 8,798 assessments were collected from 429 unique surgeons assessing 496 unique residents. Practice-ready and exceptional performances were 20 times more likely to be performed under meaningfully autonomous conditions than were other performances. Meaningful autonomy occurred most often with high-volume, easy and common cases, and less complex procedures. Eighty percent of assessments were concordant (38% practice ready/meaningfully autonomous and 42% not practice ready/not meaningfully autonomous). Most discordant assessments (13.8%) were not practice ready/meaningfully autonomous. For fifth-year residents, practice ready/not meaningfully autonomous ratings (9.7%) were more frequent than not practice ready/meaningfully autonomous ratings (7.5%). Ten surgeons (2.3%) failed to afford residents meaningful autonomy on any occasion. CONCLUSION: Resident operative performance quality is the most important determinant in attending surgeon decisions regarding resident autonomy.

Completely minimally invasive approach to restorative total proctocolectomy with j-pouch construction in children.

Restorative total proctocolectomy with J-pouch is a procedure used for children with severe ulcerative colitis or premalignant conditions like familial polyposis. The classic approach requires a laparotomy incision. Most published minimally invasive techniques still require a somewhat smaller incision to complete the procedure. We present a completely minimally invasive approach to accomplish the same goal, using a combined laparoscopic and endorectal technique and present our current clinical results with this method.

Limiting ventilator-associated lung injury in a preterm porcine neonatal model.

PURPOSE: Preterm infants are prone to respiratory distress syndrome (RDS), with severe cases requiring mechanical ventilation for support. However, there are no clear guidelines regarding the optimal ventilation strategy. We hypothesized that airway pressure release ventilation (APRV) would mitigate lung injury in a preterm porcine neonatal model. METHODS: Preterm piglets were delivered on gestational day 98 (85% of 115day term), instrumented, and randomized to volume guarantee (VG; n=10) with low tidal volumes (5.5cm3kg-1) and PEEP 4cmH2O or APRV (n=10) with initial ventilator settings: PHigh 18cmH2O, PLow 0cmH2O, THigh 1.30s, TLow 0.15s. Ventilator setting changes were made in response to clinical parameters in both groups. Animals were monitored continuously for 24hours. RESULTS: The mortality rates between the two groups were not significantly different (p>0.05). The VG group had relatively increased oxygen requirements (FiO2 50%±9%) compared with the APRV group (FiO2 28%±5%; p>0.05) and a decrease in PaO2/FiO2 ratio (VG 162±33mmHg; APRV 251±45mmHg; p<0.05). The compliance of the VG group (0.51±0.07L·cmH2O-1) was significantly less than the APRV group (0.90±0.06L·cmH2O-1; p<0.05). CONCLUSION: This study demonstrates that APRV improves oxygenation and compliance as compared with VG. This preliminary work suggests further study into the clinical uses of APRV in the neonate is warranted. LEVEL OF EVIDENCE: Not Applicable (Basic Science Animal Study).

Using the ACGME Milestones for Resident Self-Evaluation and Faculty Engagement.

BACKGROUND: Since July 2014 General Surgery residency programs have been required to use the Accreditation Council for Graduate Medical Education milestones twice annually to assess the progress of their trainees. We felt this change was a great opportunity to use this new evaluation tool for resident self-assessment and to furthermore engage the faculty in the educational efforts of the program. METHODS: We piloted the milestones with postgraduate year (PGY) II and IV residents during the 2013/2014 academic year to get faculty and residents acquainted with the instrument. In July 2014, we implemented the same protocol for all residents. Residents meet with their advisers quarterly. Two of these meetings are used for milestones assessment. The residents perform an independent self-evaluation and the adviser grades them independently. They discuss the evaluations focusing mainly on areas of greatest disagreement. The faculty member then presents the resident to the clinical competency committee (CCC) and the committee decides on the final scores and submits them to the Accreditation Council for Graduate Medical Education website. We stored all records anonymously in a MySQL database. We used Anova with Tukey post hoc analysis to evaluate differences between groups. We used intraclass correlation coefficients and Krippendorff's α to assess interrater reliability. RESULTS: We analyzed evaluations for 44 residents. We created scale scores across all Likert items for each evaluation. We compared score differences by PGY level and raters (self, adviser, and CCC). We found highly significant increases of scores between most PGY levels (p < 0.05). There were no significant score differences per PGY level between the raters. The interrater reliability for the total score and 6 competency domains was very high (ICC: 0.87-0.98 and α: 0.84-0.97). Even though this milestone evaluation process added additional work for residents and faculty we had very good participation (93.9% by residents and 92.9% by faculty) and feedback was generally positive. CONCLUSION: Even though implementation of the milestones has added additional work for general surgery residency programs, it has also opened opportunities to furthermore engage the residents in reflection and self-evaluation and to create additional venues for faculty to get involved with the educational process within the residency program. Using the adviser as the initial rater seems to correlate closely with the final CCC assessment. Self-evaluation by the resident is a requirement by the RRC and the milestones seem to be a good instrument to use for this purpose. Our early assessment suggests the milestones provide a useful instrument to track trainee progression through their residency.

The Feasibility of Real-Time Intraoperative Performance Assessment With SIMPL (System for Improving and Measuring Procedural Learning): Early Experience From a Multi-institutional Trial.

PURPOSE: Intraoperative performance assessment of residents is of growing interest to trainees, faculty, and accreditors. Current approaches to collect such assessments are limited by low participation rates and long delays between procedure and evaluation. We deployed an innovative, smartphone-based tool, SIMPL (System for Improving and Measuring Procedural Learning), to make real-time intraoperative performance assessment feasible for every case in which surgical trainees participate, and hypothesized that SIMPL could be feasibly integrated into surgical training programs. METHODS: Between September 1, 2015 and February 29, 2016, 15 U.S. general surgery residency programs were enrolled in an institutional review board-approved trial. SIMPL was made available after 70% of faculty and residents completed a 1-hour training session. Descriptive and univariate statistics analyzed multiple dimensions of feasibility, including training rates, volume of assessments, response rates/times, and dictation rates. The 20 most active residents and attendings were evaluated in greater detail. RESULTS: A total of 90% of eligible users (1267/1412) completed training. Further, 13/15 programs began using SIMPL. Totally, 6024 assessments were completed by 254 categorical general surgery residents (n = 3555 assessments) and 259 attendings (n = 2469 assessments), and 3762 unique operations were assessed. There was significant heterogeneity in participation within and between programs. Mean percentage (range) of users who completed ≥1, 5, and 20 assessments were 62% (21%-96%), 34% (5%-75%), and 10% (0%-32%) across all programs, and 96%, 75%, and 32% in the most active program. Overall, response rate was 70%, dictation rate was 24%, and mean response time was 12 hours. Assessments increased from 357 (September 2015) to 1146 (February 2016). The 20 most active residents each received mean 46 assessments by 10 attendings for 20 different procedures. CONCLUSIONS: SIMPL can be feasibly integrated into surgical training programs to enhance the frequency and timeliness of intraoperative performance assessment. We believe SIMPL could help facilitate a national competency-based surgical training system, although local and systemic challenges still need to be addressed.

Implementation of a Web- and simulation-based curriculum to ease the transition from medical school to surgical internship.

BACKGROUND: Starting a surgical internship is a stressful experience. We developed a web and simulation-based curriculum to ease this transition. METHODS: We created an educational website containing a curriculum of commonly encountered on call situations. After match day in 2003, we contacted all of our new surgical interns. We performed a confidence assessment using a Likert-scale questionnaire, and the trainees were given access to the curriculum. In June 2003, we performed human patient simulator sessions. The participants were asked to provide feedback regarding the simulator experience. During the first week of residency, they were again asked to answer the confidence questionnaire. RESULTS: Sixteen residents (94%) used the web curriculum, and 17 (100%) participated in the simulations. Eleven (65%) filled out both questionnaires. The confidence score improved from 5.4 to 6.7 (P < .0001). CONCLUSIONS: A web and simulation-based curriculum for incoming house staff is feasible. Studies are underway to validate this novel method and to expand its use for surgical education.

Duration of cardiopulmonary resuscitation before extracorporeal rescue: how long is not long enough?

Despite the extensive resources required, extracorporeal cardiopulmonary resuscitation (ECPR) has been recognized as an extension of traditional CPR. The reported duration of CPR before ECPR initiation is similar between survivors and nonsurvivors, but the duration of CPR that results in futility of care is unknown. We report two cases of prolonged CPR followed by ECPR resulting in acceptable neurologic outcomes. Ventricular tachycardia developed in a 4-year-old with myocarditis, resulting in a cardiac arrest requiring CPR for 176 minutes before initiation of extracorporeal membrane oxygenation (ECMO). The patient required ECMO for 9 days. He survived neurologically normal. A ventricular arrhythmia developed in a newborn after an arterial switch procedure, leading to cardiac arrest requiring CPR for 97 minutes before ECMO, which lasted for 11 days. Hydrocephalus developed, but the patient is progressing developmentally. The upper limit of CPR duration before ECPR resulting in acceptable neurological outcomes is unknown. Many clinical and biochemical factors are potential predictors of appropriate ECPR utility. The Extracorporeal Life Support Organization registry is a plausible forum to collect data regarding ECPR. We suggest that possible predictive variables be collected. Until then, practitioners must rely on experience and judgment regarding the value of ECPR in children.

Idiopathic thrombocytopenic purpura complicated by an intracranial hemorrhage secondary to an arteriovenous malformation.

OBJECTIVE: To report a case of idiopathic thrombocytopenic purpura (ITP) complicated by an intracranial hemorrhage (ICH) in a child with a previously undiagnosed arteriovenous malformation. CASE: We describe a child with known ITP who developed a severe headache, was evaluated in an emergency department of a community hospital, and was found by computer tomography (CT) scan to have an ICH. Despite treatment with platelets, corticosteroids, and intravenous immunoglobulin, she subsequently developed an acute change in mental status. A second CT scan showed that the hemorrhage had significantly increased in size despite treatment. The patient underwent an emergent splenectomy prior to a craniotomy to remove the hemorrhage. At the time of surgery, it was discovered that she had an arteriovenous malformation at the sight of the hemorrhage. Her recovery was unremarkable and she was discharged to home with no neurologic sequelae. CONCLUSIONS: ICH is a rare but life-threatening complication of ITP. Neurologic symptoms in a child with ITP should be quickly evaluated by CT scan. Most experts suggest careful observation for most cases of ITP. However, when neurologic symptoms occur, more aggressive treatment options must be used. Care of this child included an emergency splenectomy prior to her craniotomy. Pediatric emergency medicine practitioners must be aware of these neurologic symptoms and must not hesitate to involve pediatric surgeons and neurosurgeons in the care of the child. Prompt recognition and early intervention are the keys to improving outcomes when ICH complicates ITP.

Surgical complications of inguinal and abdominal wall hernias.

Inguinal and other abdominal wall hernias are some of the most commonly encountered problems in the pediatric population that require surgical intervention. Surgical repair is straightforward in most cases and can be performed on an outpatient basis. Complications are unusual, but potentially devastating. This article focuses specifically on incidence and risk factors of these complications, reviews the currently accepted treatment options, and points out strategies to avoid them.

Pulse laser acoustics for the characterization of inhomogeneities at interfaces of microstructures.

Interfaces between neighbouring materials are often subjected to diffusion processes which cause layers having gradually varying mechanical properties--like densities, Young's moduli or shear moduli--perpendicular to the surface or interface. In this investigation particular interest is drawn on the question how the propagation characteristics of bulk acoustic waves are affected by diffusion layers. The reflection and transmission behavior of bulk acoustic waves encountering a continuum having a spatially dependent sound velocity is discussed based on numerical simulations as well as on experimental verifications. The simulated results are part of an on-going project in which material properties of MEMS devices are investigated by short pulse laser acoustic methods. Mechanical waves are excited and detected thermoelastically using laser pulses of 70 fs duration. For metals this leads to wavelengths of 10-20 nm and the corresponding frequencies amount to 0.3-0.6 THz. In contrast to previous work done in this field in which diffusion effects are generally considered as undesirable phenomena, the deliberate realization of microstructures having well defined gradually varying material properties in one or more dimensions represents a goal of this investigation. For metallic thin film multilayers thermally induced diffusion processes have shown to be an easy and reliable technique for the realization of layered structures having continuously varying mechanical properties within several 10 nm. Among the experimental methods suitable for the in-depth profiling of submicron metallic thin films providing resolutions of several nanometers, are short pulse laser acoustic methods, Rutherford backscattering spectroscopy (RBS), and glow discharge optical emission spectroscopy (GDOES). Short pulse laser acoustic methods and RBS have the advantage to be nondestructive. The short pulse laser acoustic method is described in detail and RBS measurements are presented for verification purposes. Finally potential engineering applications like micro-machined spectrum analyzers, acoustic isolation layers, and band pass filters, operating at very high frequencies are presented.