Rainer Kubiak’s research while affiliated with University of Mannheim and other places

Background: Our previous work in a laparoscopic setting in piglets revealed that the systolic femoral artery pressure was approximately 5 % higher than its carotid counterpart, whereas the mean and diastolic values showed no significant difference. This remained idem when the intraabdominal pressure (IAP) was gradually increased. In this study, we aimed to investigate the effect of (1) intermittent IAP elevations and (2) a low cardiac output (CO) on the blood pressure (BP) difference cranially (carotid artery) and caudally (femoral artery) of a capnoperitoneum (ΔP = P a fem-P a carot). Methods: A total of twenty-two piglets (mean body weight 11.0 kg; range 8.9-13.3 kg) were studied. Of these, 14 underwent intermittent IAP elevations at 8 and 16 mmHg, and ΔP was measured. In another 8 piglets, a model of reduced CO was created by introducing an air embolism (2 ml/kg over 30 s) in the inferior caval vein (VCI) at 12 mmHg IAP to further assess the influence of this variable on ΔP. Results: Systolic ΔP remained at a mean of 5.6 mmHg and was not significantly affected by insufflation or exsufflation up to an IAP of 16 mmHg. Diastolic and mean values showed no differences between P a carot and P a fem. P a fem, systol remained higher than its carotid counterpart as long as the cardiac index (CI) was above 1.5 l/min/m(2), but fell significantly below P a carot, systol at a low CI. There was no CO-dependent effect on diastolic and mean ΔP. Repeated IAP elevations do not significantly influence ΔP. Conclusions: Intermittent IAP elevations do not significantly influence ΔP. Despite of a CO-dependent inversion of systolic ΔP, mean BP measurements at the leg during laparoscopy remain representative even at low CO values.

Purpose: There is a lack of experience with covered self-expandable stents for benign colorectal disorders in children. Methods: Five children (4M, 1F) with a median age of 5years (range, 6months-9years) who underwent treatment with covered self-expandable plastic (SEPSs) or self-expandable metal stents (SEMSs) for a benign colorectal condition between April 2005 and November 2013 were recruited to this retrospective study. Etiologies included: anastomotic stricture with (n=1) or without (n=3) simultaneous enterocutaneous fistula, as well as an anastomotic leak associated with enterocutaneous fistula (n=1). All children suffered from either Hirschsprung's disease (n=3) or total colonic aganglionosis (Zuelzer-Wilson syndrome) (n=2). Results: Median duration of individual stent placement was 23days (range, 1-87days). In all cases up to five different stents were placed over time. At follow-up two patients were successfully treated without further intervention. In another patient the anastomotic stricture resolved fully, but a coexisting enterocutaneous fistula persisted. Overall, three patients did not improve completely following stenting and required definite surgery. Stent-related problems were noted in all cases. There was one perforation of the colon at stent insertion. Further complications consisted of stent dislocation (n=4), obstruction (n=1), formation of granulation tissue (n=1), ulceration (n=1) and discomfort (n=3). Conclusions: Covered self-expandable stents enrich the armamentarium of interventions for benign colorectal disorders in children including anastomotic strictures and intestinal leaks. A stent can be applied either as an emergency procedure (bridge to surgery) or as an adjuvant treatment further to endoscopy and dilatation. Postinterventional problems are frequent but there is a potential for temporary or definite improvement following stent insertion.

There is a lack of experience with fully covered self-expandable metal stents (SEMSs) for benign esophageal disorders in children. Eleven children (six boys, five girls) with a median age of 30.5 months (range, 1 month-11 years) who underwent treatment with SEMSs for a benign esophageal condition between February 2006 and January 2014 were recruited to this retrospective study. Etiologies included esophageal atresia with postoperative stricture (n=4), recurrent fistula (n=1), and/or anastomotic leak (n=1), as well as iatrogenic perforation of the esophagus following endoscopy (n=4) or laparoscopic fundoplication (n=1). As part of an interdisciplinary cooperation patients were jointly managed from the Department of Pediatric Surgery and Central Interdisciplinary Endoscopy at our institution. Median duration of individual stent placement was 29 days (range, 17-91 days). In 4 cases up to four different SEMSs were placed successively over time. There were no complications noted at stent insertion or removal. At follow-up, 6 patients (55%) were successfully treated without further intervention. Two children each (18%) underwent one single dilatation after stent removal and remained well afterward. Three patients (27%) did not improve following stenting and required definite surgery. Minor stent-related complications were noted in 5 cases (45%), including gastroesophageal reflux (n=2), silent stent migration (n=2), and pneumonia (n=1). SEMSs for benign esophageal disorders in children can be used safely and effectively in selected cases, including esophageal anastomotic strictures, esophageal leaks following primary surgery, or perforations postdilatation. An SEMS can be applied either as an emergency procedure or as an adjuvant treatment further to endoscopy or previous surgery. Establishment of a standardized approach in the pediatric population is mandatory.

Introduction: The occasional lack of appendix and the increasing use of the Malone anterograde continence enema (MACE) procedure have expanded the need for alternative Mitrofanoff channels. The Monti procedure does not always provide adequate length, the anastomosis of the double Monti, and the potential kink of the Casale channel is not ideal for smooth catheterisation. We tested the concept of spiral intestinal lengthening and tailoring (SILT), we developed originally for short bowel syndrome, to create a long and straight alternative Mitrofanoff channel (Figure). Material and methods: After ethical approval five mini-pigs underwent spiral intestinal lengthening and tailoring (SILT) without any previous bowel dilatation procedure. (Mean bowel width was 20.5 ± 0.57 mm). The spiral line was marked on a 6-8-cm-long ileum approximately 15 mm apart with a 60° angle to the longitudinal axis of the bowel. When the incision was completed, the mesentery was incised perpendicularly where the spiral incision line met the mesentery. The maximum length segment hanging on a single 1.5-cm-wide well-vascularised mesentery was detached. The capillary red blood cell velocity (RBCV) and perfusion rate (PR) was measured at the edges of the opened bowel strip by in vivo microscopy using orthogonal polarising spectral imaging (Cytoscan A/R, Cytometrics, Philadelphia, PA, USA). The bowel strips have been reconstructed in spiral fashion over a 12F catheter and were implanted into the bladder. Viability, patency, and microcirculation were assessed 4 weeks later. Conventional microscopy with HE staining was performed. Results: The mean length of the spiral channel (100 ± 26.4 mm) was longer than could have been achieved with the double Monti or Casale procedure (4 times the bowel width). A 17% and 8.3% reduction was measured in the median values of the RBCV and the PR at the edges of the bowel strip at the primary surgery. All implanted channels remained viable, straight, patent, and easily catheterisable after 4 weeks, with full recovery of the RBCV and PR. The histology showed no necrosis or fibrosis. Conclusion: The SILT concept is suitable for creating a long and straight alternative Mitrofanoff channel. Discussion: However, the SILT technique has been reported to be successful in the clinical practice to tailor and lengthen dilated short bowel; in this study we first applied this technique on normal calibre intestine to create long alternative Mitrofanoff channel. The use of an animal model and the relative short-term observation are the limitations of this study.

Purpose: To date the clam ileocystoplasty is the preferred method of bladder augmentation in children when the urodynamic problem is non-compliance and/or detrusor overactivity. The key to this technique is the incision of the bladder wall deep into the pelvis down to the trigone in order to avoid a diverticulum like neobladder and to provide adequate margin for augmentation. The detubularised ileum flap therefore has to reach to the bottom of the divided bladder on a reliable vascular pedicle without significant tension. A short ileal mesentery caused by previous surgery, peritonitis, peritoneal dialysis or ventriculo-peritoneal shunt may complicate surgery and compromise outcome. We hypothesized we can rely on the communication of the intramural vessels within the intestine and can detubularise the ileum adjacent to the mesentery rather than along the antimesenteric line and this could be combined with ligation of some vasa recta (VR) in order to create alternative ileum flaps, which reach further into the pelvis. Our aim was to assess the viability of the alternative flaps detubularised along the paramesenteric line and measure how many VR could be sacrificed beyond the tertiary arcades. Materials and methods: After ethical approval adjacent ileal segments were detubulirased along the antimesenteric line (Group 1) and along the paramesenteric line (Group 2) in 5 minipigs in general anaesthesia. Ligation of 0,1,2,3 and 4 VR has been performed starting from the free end of the segments. The length of the ileal flaps was recorded. The microcirculation of flap edges was detected by in vivo microscopy using orthogonal polarising spectral imaging (Cytoscan A/R Cytometrics, PA, USA). Clam ileocystoplasty was performed with the ileum detubularised along the paramesenteric line without ligation of VR. Specimens of the augmented bladder were obtained after 4 weeks and stained with Hematoxilin + Eosin. Results: No alteration in capillary red blood cell velocity (RBCV) and perfusion rate (PR) was observed after paramesenteric detubularisation. The flaps in Group 2 reached 20.25 ± 0.5 mm longer vs. Control: This is 98% of the mean bowel width (20.5 ± 0.57 mm) measured in the animals. Ligation of each VR further increased the length of both flaps (mean: 10.59 ± 3.18 mm) however ligation of more than 2 VR gradually decreased the microcirculation in both groups. All animals augmented with alternative flap survived, there was no urine leak or suture break down. Histology confirmed viable bowel flaps. Conclusion: Paramesenteric detubularisation of the ileum is fully tolerated and results in longer reaching ileal flap vs. Control: Only limited ligation of VR is tolerated. Discussion: This study showed the first time that clam ileocystoplasty is feasible with ileal flap detubularised along the paramesenteric line. The use of the animal model and the relative short postoperative observation are the main limitations of this study.

Objectives In recent years laparoscopic fundoplication is increasingly performed in paediatric surgery. The aim of this study was to compare the long-term outcomes between open and laparoscopic Thal fundoplication in children. Methods This retrospective study includes children who underwent a Thal fundoplication between 3/1997-7/2009. The minimum follow-up time to enter the study was 2 years; the overall median follow-up was 77 months (range, 29–176 months). Results 101 patients were included, of which 47 underwent an open and 54 a laparoscopic Thal. Intra-operative problems, early post-operative complications, time to establish enteral feeds and length of stay did not differ among both groups. The mean duration of surgery was significantly less in the open group (OPG) (108.0 (± 7.72) versus 144.1 (± 6.36) minutes; p = 0.001) and this was mainly attributed to patients with neurological problems. Severe dysphagia requiring endoscopy was observed in 10 patients, but this did not differ significantly between groups (n = 2 in the OPG vs. n = 8 in the laparoscopic group (LAPG); p = 0.10). Overall 12 patients (11.9%) (6 in each group) required a redo-fundoplication after a median of 18.7 months (range, 6–36 months). In the whole study group, 80 patients (79.2%) were classified as having surgical results being excellent, good or satisfactory and this did not differ significantly between groups. Conclusions In the long-term open and laparoscopic Thal fundoplication have similarly good outcomes. The laparoscopic approach can be considered as an alternative, however there is not a clear superiority compared with the open counterpart.

Background: Laparoscopic fundoplication for severe gastroesophageal reflux (GOR) is well established in children. However, there are only a few reports on the long-term nutritional outcome following fundoplication. The aim of this study was to assess weight gain following fundoplication in children. Methods: In this study, 127 children who underwent laparoscopic fundoplication ± gastrostomy between July 1998 and April 2007 were followed up for a median of 29.6 months postsurgery. Data (demography, weight) at fundoplication were collected prospectively, with ethical approval. Weights were converted to Z-scores for age (Z-score of 0 is equivalent to 50th percentile, -1 to 16th centile, and -2.0 is equivalent to 2nd centile). Severe failure to thrive (FTT) was defined as a Z-score of less than or equal to -2. Data were compared using the two-tailed Student t test, and multilevel regression modeling was applied. Results: At the time of operation, patients had a low weight-for-age Z-score (-1.87 ± 0.19) and 61 children (48%) had FTT. Children who received a simultaneous gastrostomy had a significantly lower Z-score at operation (-2.80 ± 0.22) than those who did not (-0.68 ± 0.25, p < 0.001). Overall, patients exhibited significant catch-up weight gain following surgery (+0.88 ± 0.14, p < 0.001). The greatest increase in weight was mostly marked in patients who had a gastrostomy inserted (+1.22 ± 0.20, p < 0.001), but it was also significant in patients who did not receive a gastrostomy (+0.44 ± 0.17, p = 0.013). Catch-up weight gain occurred in neurologically impaired (NI) patients with (+1.31 ± 0.22, p < 0.001) or without (+0.81 ± 0.29, p = 0.012) gastrostomy. Weight of neurologically normal (NN) patients was within normal range but slightly lower than average before surgery (-0.45 ± 0.24) and this did not significantly change following surgery. There was no significant catch-up weight gain in patients (n = 9) with "esophageal pathologies" (Z-score of -1.35 ± 0.61 at operation compared with -0.35 ± 0.34 at follow-up; p = 0.14). Conclusions: Laparoscopic fundoplication (with or without gastrostomy placement) resulted in significant weight gain in children with GOR. Insertion of a gastrostomy at the same time resulted in greater weight gain. Pronounced weight gain occurred in NI children, whereas NN children and those with esophageal pathologies did not demonstrate any significant benefit in terms of weight gain following fundoplication.

Background: Children with ventriculo-peritoneal (V-P) shunts have a significant risk of morbidity and mortality from infections. Many of these patients have other co-morbidities and may require subsequent abdominal surgery, including fundoplication with or without gastrostomy placement. The aim of our study was to assess the outcomes of laparoscopic fundoplication in children with a V-P shunt in situ. Subjects and methods: A retrospective review of a prospectively maintained database on children who underwent laparoscopic fundoplication with a V-P shunt in situ at the time of surgery between July 1998 and March 2011 was conducted. Primary outcomes included intra- and postoperative complications as well as shunt-related problems within a 6-month period after surgery. The subset of children with V-P shunts was compared with those who underwent fundoplication without shunts. Variables were compared using the two-tailed Student's t test, chi-squared test, or Fisher's exact test. Significance was defined as P≤.05. Results: Out of a total of 343 children who underwent fundoplication, 11 (6 girls, 5 boys) had a V-P shunt in situ at the time of surgery (3.2%). The median age at laparoscopy was 2.2 years (range, 0.7-13.8 years). Weight at surgery ranged from 5.8 to 39.0 kg (median, 12.0 kg). The operating time (without gastrostomy placement) was 105 minutes (range, 80-140 minutes). In 6 patients (55%) moderate to severe adhesions were documented, but only 1 child required conversion to open surgery because of bleeding from the omentum. In a second patient the colon was perforated during insertion of the percutaneous endoscopic gastrostomy (PEG) and repaired laparoscopically. There was no postoperative shunt dysfunction or infection related to the laparoscopic procedure. There was no significant difference between V-P shunt patients and the main cohort regarding operating time, conversion to open surgery, need for admission to a high-care unit, opiate requirements, time to full feeds, and length of hospital stay. Conclusions: These data suggest that laparoscopic fundoplication is feasible in children with previous V-P shunt placement. Although there were considerable adhesions in approximately half of these patients, the rate for conversion to open surgery was low. Complications associated with simultaneous PEG insertion occur and should be anticipated by placing the gastrostomy under laparoscopic guidance.

An 8-year-old boy was admitted for excision of a putative 'blue nevus' on the left foot. Histological examination and immunohistochemistry revealed a Bednar tumour, the pigmented variant of dermatofibrosarcoma protuberans. Surgical options considered by a multidisciplinary team included wide local excision, Mohs micrographic surgery or a staged excision with examination of several histological sections. The third alternative procedure was chosen after consideration of tumour and patient factors to achieve the best possible clinical, cosmetic and functional outcome. After the final surgical procedure with resection of the third metatarsal bone, all peripheral margins were free of tumour, and the interdigital space was reconstructed with a pedicled pulpa flap. Three years after surgery, there was no tumour recurrence, and further long-term follow-up for this patient will be provided.

An unusual complication following colonic interposition for oesophageal atresia is described, where a fistula between an aberrant right subclavian artery and the colon graft caused severe haemorrhage. As in cases of aorto-oesophageal fistulae from foreign body ingestion, we experienced a 'herald'-bleed before a second near-fatal event. In such cases, the clinical assumption should be that the source of bleeding is a major artery and appropriate resuscitation including preparations for immediate thoracotomy is required. Consideration should also be given to this potential complication when using the mediastinal route for an oesophageal replacement graft.