Histopathological effects of modern topical sealants on the liver surface after hepatectomy: an experimental swine study

The present study aimed to determine the impact of different sealant materials on histopathological changes to the liver surface after liver resection. Thirty-six landrace pigs underwent left anatomical hemihepatectomy and were assigned to a histopathological control group (HPC, n = 9) with no bleeding control, a clinically simulated control group (CSC, n = 9) with no sealant but bipolar cauterization and oversewing of the liver surface, and two treatment groups (n = 9 each) with a collagen-based sealant (CBS) or a fibrinogen-based sealant (FBS) on resection surface. After postoperative day 6, tissue samples were histologically examined. There were no significant differences in preoperative parameters between the groups. Fibrin production was higher in sealant groups compared with the HPC and CSC groups (both p < 0.001). Hepatocellular regeneration in sealant groups was higher than in both control groups. A significantly higher regeneration was seen in the FBS group. Use of sealants increased the degree of fibrin exudation at the resection plane. Increased hepatocellular necrosis was seen in the CBS group compared with the FBS group. The posthepatectomy hepatocellular regeneration rate was higher in the FBS group compared with the CBS group. Randomized studies are needed to assess the impact of sealants on posthepatectomy liver regeneration in the clinical setting.

Characterization of device-related interruptions in minimally invasive surgery: need for intraoperative data and effective mitigation strategies

BACKGROUND

The burden of device-related interruptions is expected to increase as modern surgical practices adopt complex minimally invasive surgery devices. Currently, there is a paucity of empiric data that examined the nature of device-related interruptions using comprehensive intraoperative data.

METHODS

We performed a cross-sectional study of consecutive elective laparoscopic general surgery cases performed in one operating room (OR) at a referral center between April 2014 and April 2016. The included cases were directly observed using a comprehensive multiport data recorder called the OR Black Box. The data were synchronized, encrypted, and reviewed by expert surgeon assessors. The assessors characterized device-related interruptions that occurred during operations. The prevalence of the cases with device-related interruptions was calculated. Device-related interruptions were classified into a priori categories of (1) absent/wrong device; (2) improper assembly; (3) loss of sterility; (4) disconnection; and (5) device failure.

RESULTS

In a cohort of 210 cases, 64 (30%) had at least one device-related interruption. Sleeve gastrectomy (52%) and oncologic gastrectomy (43%) procedures experienced the highest prevalence of device-related interruptions. Device failure was the most frequently chosen category with laparoscopic staplers implicated in more than half of these failures. Three failure modes were described for laparoscopic stapler, of which stapler malfunction (46%) was the most common.

CONCLUSIONS

Device-related interruptions occurred frequently in the OR and could be characterized into one of the five categories. Understanding the nature of the device-related interruptions can help guide implementation of safety interventions and user training in the future.

Mechanical strength of biliary defect closure after topical sealing: Comparison of four sealants in a porcine model

BACKGROUND/OBJECTIVE

Biliary leakage is a potential complication of liver resection and is still a concern. The aim of the present study was to evaluate the effectiveness of four routinely used sealants in preventing bile leakage under pressure from an induced perforation of the gallbladder in a porcine model.

METHODS

Forty Landrace pigs were randomly assigned to one of five groups. These included a control group (n = 8) and one group each for the sealants TachoSil®, TissuCol Duo®, Coseal®, and FloSeal® (n = 8 per group). In the control group, the perforation was left unsealed. To evaluate the biliostatic potential of the sealants, we measured the pressure that was needed to induce leakage (mmHg) and the gallbladder volume (cc) at the time of leakage in each group.

RESULTS

A significantly higher mean pressure was required to induce leakage in the sealant groups compared with the control group. However, the biliostatic effects were heterogeneous among the sealant groups. Sealants with the highest to lowest effectiveness were TachoSil, Coseal, TissuCol, and FloSeal. The mean gallbladder volume at the time of leakage also varied between sealant groups.

CONCLUSION

Biliostatic properties are markedly improved by the use of modern sealants compared with using no sealant. However, the advantages and disadvantages of using sealants should be carefully considered in each clinical situation. The effectiveness of the sealants should be evaluated in chronic and clinical studies.

Endonasal Endoscopic Treatment of Parasellar Arachnoid Cyst: Report of a Case

A 40-year-old man presented with intractable headache of 5-year duration and a 1-month history of intermittent cerebrospinal fluid (CSF) rhinorrhea. Magnetic resonance imaging showed a cystic lesion with signal characteristics similar to that of CSF. The patient underwent endonasal endoscopic surgery of the sphenoid sinus and the fistula was reinforced with facia, muscle, cartilage, and posterior septal flap while performing cystocisternostomy. The postoperative course was uneventful, CSF leakage stopped, and headache improved. Postoperative imaging revealed total collapse of the cyst cavity. Based on our findings, endonasal endoscopic treatment of the sellar and parasellar arachnoid cysts, if presenting into the sphenoid sinus, could be an acceptable minimally invasive alternative to the conventional modalities.

Analysis of the hemostatic potential of modern topical sealants on arterial and venous anastomoses: an experimental porcine study

One of the widely accepted adjunctive agents in the variety of surgical modalities are sealants. Our study aim was to compare four commonly used modern sealants in a standardized experimental setting to assess their feasibility, and hemostatic efficacy in vascular anastomosis. Forty landrace pigs (weight: 24.7 ± 3.8 kg) were randomized into the control (n = 8) and four sealant groups; TachoSil® (n = 8), Tissucol Duo® (n = 8), Coseal® (n = 8), and FloSeal® (n = 8). After doing a portal vein end-to-end anastomosis as well as stitches of aortic incision, the sealants were applied on anastomotic site. The control group was left intact. In portal vein anastomosis, the sealants led to a complete hemostasis significantly better than control group. The mean of blood loss was also significantly reduced. In successful subgroups, there was a difference in the mean-time to reach complete hemostasis ranging from 15 s in Coseal® to 76 s in FloSeal® group (p  < 0.05). In aortotomy experiments, except Tissucol Due®, which had insufficient hemostasis, other sealants led to a complete hemostasis. The mean blood loss was significantly reduced in sealants groups as well. The four sealants are effective in reducing the suture-hole bleeding in portal vein anastomosis. However, the hemostatic potential is heterogeneous among sealants. This means that "one-size-fits-all" approach is not appropriate for application of sealants in diversity of vascular surgery and it should be based on the type and the severity of injury and the structure of tissue. Comparison of hemostasis efficacy of four modern sealants (TachoSil®, Tissucol Duo®, Coseal®, and FloSeal®) in vascular anastomosis in porcine model. The figures below show the total blood loss (g) in the control and sealant groups after aortotomy (left) and portal vein anastomosis (right). The mean of blood loss decreased significantly by the usage of sealants in both experiment groups as compared to control group (*: p < 0.05; sealant groups vs. control group). 1. The right column shows the mean of blood loss (g) in all experiments in each group. 2. The middle column presents the subgroup with unsuccessful hemostasis at the end of observation time (Tmax = 20 sec. for aortotmy and 300 sec. for portal vein anastomosis). 3. The left column shows mean of total blood loss in subgroups with successful hemostasis during observation time (20 sec for aortotomy and 300 sec for portal vein).

Analysis of the biliostatic potential of two sealants in a standardized porcine model of liver resection

BACKGROUND

Improved resection techniques has decreased mortality rate following liver resections(LRx). Sealants are known as effective adjuncts for haemostasis after LRx. We compared biliostatic effectiveness of two sealants in a standardized porcine model of LRx.

MATERIAL AND METHODS

We accomplished left hemihepatectomy on 27 pigs. The animals were randomized in control group(n = 9) with no sealant and treatment groups (each n = 9), in which resection surfaces were covered with TachoSil^® and TissuFleece^®/Tissucol Duo^®. After 5 days the volume of ascites(ml), bilioma and/or bile leakages and degree of intra-abdominal adhesions were analysed.

RESULTS

Proportion of ascites was lower in TissuFleece/Tissucol Duo^® group. The ascites volume was lower in TachoSil^® group. In sealant groups, increased adhesion specially in the TachoSil^® group was seen. A reduction of the "bilioma rate" was seen in sealant groups, which was significantly lower in TissuFleece^®/Tissucol Duo^® group.

CONCLUSION

In a standardized condition sealants have a good biliostatic effect but with heterogeneous potentials. This property in combination with the cost-benefit analysis should be the focus of future prospective studies.

Clinical outcomes of MyoRing implantation in keratoconic eyes by using the Femtosecond laser technology

Purpose: To assess the outcomes of the insertion of the MyoRing (DIOPTEX, GMBH, Linz, Austria) by applying the Femtosecond Laser Technology (FLT) method in eyes that have keratoconus problem. Methods: A prospective, nonrandomized, clinical examination was managed. 27 eyes of 15 subjects with stable keratoconus (6 females and 9 males), with lifetimes differing from 14 to 49 years were involved. All subjects have problems about decreased fine-accurate ocular awareness, lens intolerantness or trouble, and also the middle corneal height larger than 350 micrometers. MyoRing additions of about 320 micrometers into height and 2.5 mm into radius were inserted in each subject inside an Intrastromal Corneal Pocket using(ICP) formed with applying FLT. Ocular, refractive errors, corneal shape, and pachymetry changes were assessed throughout a 6-months follow-up period. Results: The average UDVA (uncorrected distance visual acuity) notably increased originating at 1.73 ± 0.53 LogMAR preoperationally to 0.54 ± 0.40 LogMAR post-operationally. The average CDVA (corrected distance ocular awareness) notably increased from 0.59 ± 0.47 LogMAR preoperationally to 0.27 ± 0.16 LogMAR post-operationally. The change in the average UDVA and CDVA was analytically meaningful (P< 0.000). The average reduction in the average keratometry from preoperational to 26 weeks post operational was -6.41 ± 3.62 D. This change was analytically meaningful (P< 0.000). The average lowest and highest keratometry amounts were similarly analytically notable at shorter than 26 weeks preoperatively. A notable increase in UDVA and CDVA was observed 26 weeks following the operation, that was compatible with the notable decrease in sphere and cylinder. Moreover, a notable corneal straightening with an average amount of -6.41 ± 3.62 diopters (D) was determined. Conclusion: MyoRing implantation employing FLT would be a harmless, effective, and predictable method to treat selected subjects of keratoconus, being a helpful choice for the therapy of keratoconus.

Is Canadian surgical residency training stressful?

BACKGROUND

Surgical residency has the reputation of being arduous and stressful. We sought to determine the stress levels of surgical residents, the major causes of stress and the coping mechanisms used.

METHODS

We developed and distributed a survey among surgical residents across Canada.

RESULTS

A total of 169 participants responded: 97 (57%) male and 72 (43%) female graduates of Canadian (83%) or foreign (17%) medical schools. In all, 87% reported most of the past year of residency as somewhat stressful to extremely stressful, with time pressure (90%) being the most important stressor, followed by number of working hours (83%), residency program (73%), working conditions (70%), caring for patients (63%) and financial situation (55%). Insufficient sleep and frequent call was the component of residency programs that was most commonly rated as highly stressful (31%). Common coping mechanisms included staying optimistic (86%), engaging in enjoyable activities (83%), consulting others (75%) and exercising (69%). Mental or emotional problems during residency were reported more often by women (p = 0.006), who were also more likely than men to seek help (p = 0.026), but men reported greater financial stress (p = 0.036). Foreign graduates reported greater stress related to working conditions (p < 0.001), residency program (p = 0.002), caring for family members (p = 0.006), discrimination (p < 0.001) and personal and family safety (p < 0.001) than Canadian graduates.

CONCLUSION

Time pressure and working hours were the most common stressors overall, and lack of sleep and call frequency were the most stressful components of the residency program. Female sex and graduating from a non-Canadian medical school increased the likelihood of reporting stress in certain areas of residency.

Routine induction therapy in living donor liver transplantation prevents rejection but may promote recurrence of hepatitis C

BACKGROUND

Routine induction therapy in living donor liver transplantation (LDLT) has not been well described.

METHODS

We reviewed outcomes of induction therapy with rabbit antithymocyte globulin (rATG) or basiliximab within 1 year of LDLT.

RESULTS

Between 2002 and 2007, 184 adults underwent LDLT and received induction therapy in addition to standard immunosuppression. Acute cellular rejection (ACR) developed in 17 of 130 patients (13.1%) who received rATG and 13 of 54 patients (24.1%) who received basiliximab (P = .066). The interval between transplantation and rejection as well as rejection severity was similar in patients who received rATG and those who received basiliximab. Hepatitis C (HCV) recurrence requiring initiation of antiviral therapy was more common in patients who received rATG compared with basiliximab (34.5% vs 8.7%; P = .021), and in those who received induction combined with tacrolimus as opposed to cyclosporine (38.5% vs 3.9%; P = .001). rATG and basiliximab were associated with excellent patient and graft survivals well as low rates of opportunistic infections and malignancies.

CONCLUSION

Induction with rATG or basiliximab was well tolerated and highly effective at preventing ACR within 1 year of LDLT, but may be associated with a higher risk of clinically significant HCV recurrence in some patients.

Early detection of metabolic changes using microdialysis during and after experimental kidney transplantation in a porcine model

BACKGROUND

Microdialysis (MD) can detect organ-related metabolic changes before they become measurable in plasma through the biochemical parameters. This study aims to evaluate the early detection of metabolic changes during experimental kidney transplantation (KTx).

MATERIAL AND METHODS

During preparation of 8 donor kidneys, one MD catheter was inserted in the renal cortex and samples were collected. After a 6-hour cold ischemia time (CIT), kidneys were implanted in the 8 recipient pigs. Throughout the warm ischemia time (WIT) and after reperfusion, kidneys were monitored. The interstitial glucose, lactate, pyruvate, glutamate, and glycerol concentrations were evaluated.

RESULTS

A significant decline in glucose level was observed at the end of CIT. The lactate level was reduced to the minimum point of 0.35 ± 0.08 mmol/L in CIT. After reperfusion, lactate values raised significantly. During the WIT, the pyruvate level increased, continued until the end of the WIT. For glutamate, a steady increase was noted during explantation, CIT, WIT, and early reperfusion phases. The increase of glycerol value continued in the early postreperfusion, which was then followed by a sharp decline.

CONCLUSION

MD is a fast and simple minimally invasive method for measurement of metabolic substrates in renal parenchyma during KTx. MD offers the option of detecting minor changes of interstitial glucose, lactate, pyruvate, glutamate, and glycerol in every stage of KTx. Through the use of MD, metabolic changes can be continuously monitored during the entire procedure of KTx.

Appropriate donor size for porcine liver xenotransplant

OBJECTIVES

Owing to an imbalance between demand and supply, which is more prominent in pediatric transplant, every year more patients lose their lives on waiting lists. In addition to the use of deceased-donor split and living-donor organs, xenotransplant could provide a solution if associated problems, such as immunologic and physiologic ones, are solved. This study sought to analyze the surgical aspects for liver xenotransplant in a porcine model.

MATERIALS AND METHODS

Landrace pigs (n=22, 23 to 37 kg) underwent a laparotomy under general anesthesia. The hepatic hilum was prepared and the common bile ducts, common hepatic artery, portal vein, supra- and infrahepatic inferior vena cava were identified. The length and diameter of each vessel and bile duct and the weight of the liver were measured.

RESULTS

Pearson tests showed a clear correlation between the increase of the pigs' weight and the livers' weight, and the length of the vessels and the bile ducts. We did not find a clear correlation between the increase of the pigs' liver weight and the diameters of the vessels and the bile duct.

CONCLUSIONS

As the first reporting, this study on xenotransplants from the surgical point of view, we postulate that it could be possible to estimate the size of the liver and the proper length of its vessels and bile duct by weighing only the pigs. It was not feasible to match the diameter of mentioned structures by the livers' weight. However, the weight of pig's liver as well as vascular anatomy of pigs appeared to be suitable alternative for the human liver.

Adult living liver donors have excellent long-term medical outcomes: the University of Toronto liver transplant experience

Right lobe living donor liver transplantation is an effective treatment for selected individuals with end-stage liver disease. Although 1 year donor morbidity and mortality have been reported, little is known about outcomes beyond 1 year. Our objective was to analyze the outcomes of the first 202 consecutive donors performed at our center with a minimum follow-up of 12 months (range 12-96 months). All physical complications were prospectively recorded and categorized according to the modified Clavien classification system. Donors were seen by a dedicated family physician at 2 weeks, 1, 3 and 12 months postoperatively and yearly thereafter. The cohort included 108 males and 94 females (mean age 37.3 +/- 11.5 years). Donor survival was 100%. A total of 39.6% of donors experienced a medical complication during the first year after surgery (21 Grade 1, 27 Grade 2, 32 Grade 3). After 1 year, three donors experienced a medical complication (1 Grade 1, 1 Grade 2, 1 Grade 3). All donors returned to predonation employment or studies although four donors (2%) experienced a psychiatric complication. This prospective study suggests that living liver donation can be performed safely without any serious late medical complications and suggests that long-term follow-up may contribute to favorable donor outcomes.

A graft to body weight ratio less than 0.8 does not exclude adult-to-adult right-lobe living donor liver transplantation

Many centers require a minimal graft to body weight ratio (GBWR) >or= 0.8 as an arbitrary threshold to proceed with right-lobe living donor liver transplantation (RL-LDLT), and there is often hesitancy about transplanting lower volume living donor (LD) liver grafts into sicker patients. The data supporting this dogma, based on the early experience with RL-LDLT at Asian centers, are weak. To determine the effect of LD liver volume in the modern era, we investigated the impact of GBWR on the outcome of RL-LDLT with a GBWR as low as 0.6 at the University of Toronto. Between April 2000 and September 2008, 271 adult-to-adult RL-LDLT procedures and 614 deceased donor liver transplants were performed. Twenty-two living donor liver transplantation (LDLT) cases with a GBWR of 0.59 to 0.79 (group A) were compared with 249 LDLT cases with a GBWR >or= 0.8 (group B) and with 66 full-graft deceased donor liver transplants (group C), who were matched 3:1 according to donor and recipient age, Model for End-Stage Liver Disease score, and presence of hepatitis C and hepatocellular carcinoma with the low-GBWR group. Portal vein shunts were not used. Markers of reperfusion injury [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], graft function (international normalized ratio and bilirubin), complications graded by the Clavien score, and graft and patient survival were compared. As expected, LD recipients had a significantly shorter cold ischemia time (94 +/- 43 minutes for A, 96 +/- 57 minutes for B, and 453 +/- 152 minutes for C, P = 0.0001). However, the peak AST, peak ALT, absolute decrease in the international normalized ratio, day 7 bilirubin level, postoperative creatinine clearance, complication rate graded by the Clavien score, and median hospital stay were similar in all groups. The rate of biliary complications was higher with LD grafts than deceased donor grafts (19% for A versus 10% for B and 0% for C, P = 0.2). Patient survival was similar in all groups at 1, 3, and 5 years (91% for A versus 89% for B and 93% for C at 1 year, 87% for A versus 81% for B and 89% for C at 3 years, and 83% for A versus 81% for B and 87% for C at 5 years, P = 0.63). A Cox proportional regression analysis revealed only hepatitis C virus as a risk factor for poorer graft survival and not GBWR as a continuous or categorical variable. In conclusion, we found no evidence of inferior outcomes with smaller size grafts versus larger size LD grafts or full-size deceased donor grafts. Further studies are warranted to examine the factors affecting the function of smaller grafts for living liver donation and thereby define the safe lower limits for transplantation.

Financial, vocational, and interpersonal impact of living liver donation

The ability to inform prospective donors of the psychosocial risks of living liver donation is currently limited by the scant empirical literature. The present study was designed to examine donor perceptions of the impact of donation on financial, vocational, and interpersonal life domains and identify demographic and clinical factors related to longer recovery times and greater life interference. A total of 143 donors completed a retrospective questionnaire that included a standardized measure of life interference [Illness Intrusiveness Rating Scale (IIRS)] and additional questions regarding the perceived impact of donation. Donor IIRS scores suggested that donors experience a relatively low level of life interference due to donation [1.60 +/- 0.72, with a possible range of 1 ("not very much" interference) to 7 ("very much" interference)]. However, approximately 1 in 5 donors reported that donating was a significant financial burden. Logistic regression analysis revealed that donors with a psychiatric diagnosis at or prior to donation took longer to return to their self-reported predonation level of functioning (odds ratio = 3.78, P = 0.016). Medical complications were unrelated to self-reported recovery time. Multiple regression analysis revealed 4 independent predictors of greater life interference: less time since donation (b = 0.11, P < 0.001), income lower than CAD$100,000 (b = 0.28, P = 0.038), predonation concerns about the donation process (b = 0.24, P = 0.008), and the perception that the recipient is not caring for the new liver (b = 0.12, P = 0.031). In conclusion, life interference due to living liver donation appears to be relatively low. Donors should be made aware of risk factors for greater life disruptions post-surgery and of the potential financial burden of donation.

Recipient age affects long-term outcome and hepatitis C recurrence in old donor livers following transplantation

We studied the role of donor and recipient age in transplantation/ischemia-reperfusion injury (TIRI) and short- and long-term graft and patient survival. Eight hundred twenty-two patients underwent deceased donor liver transplantation, with 197 donors being > or = 60 years old. We evaluated markers of reperfusion injury, graft function, and clinical outcomes as well as short- and long-term graft and patient survival. Increased donor age was associated with more severe TIRI and decreased 3- and 5-year graft survival (73% versus 85% and 72% versus 81%, P < 0.001) and patient survival (77% versus 88% and 77% versus 82%, P < 0.003). Hepatitis C virus (HCV) infection and recipient age were the only independent risk factors for graft and patient survival in patients receiving an older graft. In the HCV(+) cohort (297 patients), patients > or = 50 years old who were transplanted with an older graft versus a younger graft had significantly decreased 3- and 5-year graft survival (68% versus 83% and 64% versus 83%, P < 0.009). In contrast, HCV(+) patients < 50 years old had similar 3- and 5-year graft survival if transplanted with either a young graft or an old graft (81% versus 82% and 81% versus 82%, P = 0.9). In conclusion, recipient age and HCV status affect the graft and patient survival of older livers. Combining older grafts with older recipients should be avoided, particularly in HCV(+) patients, whereas the effects of donor age can be minimized in younger recipients.

A single-center experience of 500 liver transplants using the modified piggyback technique by Belghiti

Over the past 4 decades, the surgical techniques of liver transplantation (LTx) have permanently evolved and been modified. Among these, the modified piggyback (MPB) technique by Belghiti offers specific advantages. The objective of this study was to present our single-center experience with the MPB technique in 500 cases. Recipients' perioperative data were prospectively collected and evaluated. Postoperative and specific complications, stay in the intensive and intermediate care unit, and the mortality rate with cause of death were analyzed. Most recipients were classified as Child C (49.1%). For the patients who underwent LTx for the first time, alcoholic (23.9%) and viral (22.2%) cirrhosis and hepatocellular carcinoma (15.1%) were the prevalent indications. The overall median warm ischemia time, anastomosis duration, and operative time were 45, 108, and 320 minutes, respectively. The median intraoperative blood loss was 1500 mL. A venovenous bypass was never needed to maintain hemodynamic stability. Only in a few cases was temporary inferior vena cava clamping necessary. Most prominent surgical complications were hemorrhage, hematoma, and wound dehiscence. Renal failure occurred in 6.2% of patients. The overall median stay in the intensive and intermediate care unit was 14 days. The mortality rates within 30 and 90 days were 6.3% and 13.3%, respectively. No technique-related death occurred. The MPB technique by Belghiti is a feasible and simple LTx technique. The caval flow is preserved during the anhepatic phase, and this minimizes the need for venovenous bypass or portocaval shunt. This technique requires only 1 caval anastomosis, which is easy to perform with a short anhepatic phase. To minimize the risk of outflow obstruction, attention should be paid by doing a wide cavocavostomy cranially to the donor inferior vena cava in a door-lock manner. This technique can be applied in almost all patients undergoing LTx for the first time and liver retransplantation as well.

Adult right-lobe living liver donors: quality of life, attitudes and predictors of donor outcomes

To refine selection criteria for adult living liver donors and improve donor quality of care, risk factors for poor postdonation health-related quality of life (HRQOL) must be identified. This cross-sectional study examined donors who underwent a right hepatectomy at the University of Toronto between 2000 and 2007 (n = 143), and investigated predictors of (1) physical and mental health postdonation, as well as (2) willingness to participate in the donor process again. Participants completed a standardized HRQOL measure (SF-36) and measures of the pre- and postdonation process. Donor scores on the SF-36 physical and mental health indices were equivalent to, or greater than, population norms. Greater predonation concerns, a psychiatric diagnosis and a graduate degree were associated with lower mental health postdonation whereas older donors reported better mental health. The majority of donors (80%) stated they would donate again but those who perceived that their recipient engaged in risky health behaviors were more hesitant. Prospective donors with risk factors for lower postdonation satisfaction and mental health may require more extensive predonation counseling and postdonation psychosocial follow-up. Risk factors identified in this study should be prospectively evaluated in future research.

Evaluation of the combined laparoscopic and mediastinoscopic esophagectomy technique

BACKGROUND

Laparoscopic esophagectomy is technically difficult especially during dissection in the upper mediastinum. This limitation may be surpassed with the help of mediastinoscopy or of the recently introduced robotic surgical systems. The aim of the present study was to evaluate in an experimental porcine model the feasibility of the combined laparoscopic and mediastinoscopic transhiatal esophagectomy technique and to compare it with the robotic-assisted transhiatal and conventional approaches.

MATERIALS AND METHODS

Transhiatal esophagectomy was performed in Landrace pigs under general anesthesia using three different techniques: Group A (n = 9): combined laparoscopic and mediastinoscopic, group B (n = 4): robotic-assisted and group C (n = 8): conventional "open". The feasibility, difficulty and accuracy of the procedure along with operative time, blood loss, intraoperative incidents and overall satisfaction of the surgical team were assessed for each technique.

RESULTS

Operations in group A were feasible and reproducible. Although the procedure was technically difficult, the constant view on the operative field was highly appreciated by the operative team and facilitated an accurate and safe dissection. The main intraoperative complications were related to the side-effects of tension pneumothorax accompanying pleural injuries. In group B the features of the robotic system reduced the difficulty of dissection and obviated the need for mediastinoscopy. Operations in group C were quick and almost incident-free, facilitated also by the particularities of the animal model that could not reproduce identically the clinical situation.

CONCLUSIONS

The combined laparoscopic and mediastinoscopic esophagectomy technique is feasible and offers certain advantages over the open approach while the robotic-assisted approach is an emerging less difficult alternative. Further studies are required to establish whether the advantages of minimally-invasive approach compensate for the increased technical difficulty and prolonged operative time.

Gas-chamber mediastinoscopy for dissection of the upper esophagus

AIM

Mediastinoscopy has the potential to bring under view the upper mediastinum, the area most difficult to dissect during transhiatal esophagectomy. The aim of the present study was to evaluate in an animal model the feasibility of the gas-chamber mediastinoscopy technique for dissection of the upper esophagus.

METHODS

Operations were performed in nine Landrace pigs using a 30 degrees laparoscope and conventional 35-cm laparoscopic instruments. Through a left collar incision a virtual space was created with sharp and blunt dissection around the cervical esophagus and insufflated with CO2 at a pressure of 5 mmHg. Using one 10-mm optical trocar and two 5-mm working trocars dissection advanced in the periesophageal space with the aim to reach at least to the tracheal bifurcation.

RESULTS

Performed under visual control, the procedure was accurate and safe, the level of tracheal bifurcation being reached in all cases. Anatomical structures such as trachea and its bifurcation, pleura, pericardium, arch of the azygos vein and periesophageal lymph nodes were visible during the operation. There were no major intraoperative incidents and blood loss was minimal.

CONCLUSIONS

The technique of gas-chamber mediastinoscopy is feasible. It allows a fair amount of freedom of movement for the working instruments and offers a good view on the operative field for a controlled and accurate dissection. Further evaluation in experimental and clinical studies is required to establish the role of this procedure in esophageal surgery.

Experimental study of cardiorespiratory and stress factors in esophageal surgery using robot-assisted thoracoscopic or open thoracic approach

BACKGROUND

Our aim was to compare cardiovascular and stress response to robotic technology during thoracoscopic mobilization and anastomosis of the esophagus vs the conventional open approach.

DESIGN

Randomized experimental study.

SETTING

Department of Experimental Surgery, University of Heidelberg.

SUBJECTS

Twelve pigs randomized to undergo robotic or conventional surgery (6 animals each).

INTERVENTIONS

Fundus rotation gastroplasty followed by esophageal mobilization and intrathoracic anastomosis by conventional or robotic surgery.

MAIN OUTCOME MEASURES

Mean arterial pressure, central venous pressure, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, cardiac output, pulmonary vascular resistance, partial oxygen pressure, alveolar-arterial difference in partial pressure of oxygen, and arteriovenous oxygen content difference measured preoperatively, during esophageal manipulation, and 30 minutes after operation. Operative stress was assessed by plasma levels of cortisol and substance P.

RESULTS

Hemodynamic measures showed higher intraoperative central venous pressure and pulmonary vascular resistance in the open surgery group, whereas cardiac output was significantly decreased compared with the robotic group. Blood gas values showed significant deterioration during esophageal manipulation with open surgery in contrast to the robotic group. Substance P and cortisol levels were significantly higher with the open approach.

CONCLUSIONS

The robot-assisted approach is associated with improved intraoperative cardiopulmonary function and seems to be a less stressful technique.

Partial Cholecystectomy as a Safe and Viable Option in the Emergency Treatment of Complex Acute Cholecystitis: A Case Series and Review of the Literature

Partial cholecystectomy (PC) is an alternative choice to standard cholecystectomy in situations with increased risk of Calot's components injury. We reported our experience with the patients treated with PC and reviewed the literature. Fifty-four patients with complex acute cholecystitis underwent PC, including conventional partial cholecystectomy (CPC; n = 48) and laparoscopic partial cholecystectomy (LPC; n = 6). The clinical diagnosis was verified by ultrasonography. In addition, we reviewed 1190 published cases (1972–2005) who underwent a “nonconventional” surgery for severe cholecystitis, including cholecystostomy, CPC, or LPC. Review of the literature, including our cases, showed a male:female ratio of 1.3:1. The major operative indication was severe acute cholecystitis. Procedures included cholecystostomy (65.8%) and PC (34.2%). In the follow-up (n = 1190), biliary leak (4.8%), retained stones (4.6%), recurrent symptoms (2.3%), wound infections (1.9%), persistent biliary fistula (0.9%), and prolonged biliary drainage (0.2%) were found, with an overall mortality rate of 9.4 per cent. In 133 patients, because of postoperative complications ( e.g., recurrent symptoms, remaining common bile duct stones, or persistence of bile fistula), reoperation was necessary, including 121 cases (90.1%) of cholecystectomy, whereas the other 11 patients underwent other procedures such as common bile duct exploration or closure of the fistula. The surgical trend for complex acute cholecystitis treatment has been changed from only cholecystostomy to a spectrum of cholecystostomy, CPC, and LPC with the progressive increase of PC. The proportion of the LPC compared with CPC has also increased during recent years. It seems that PC is a safe procedure for treating complicated acute cholecystitis. Whether the indication and need for alternative techniques to standard cholecystectomy is changing should be evaluated in future studies.

Partial cholecystectomy as a safe and viable option in the emergency treatment of complex acute cholecystitis: a case series and review of the literature

Partial cholecystectomy (PC) is an alternative choice to standard cholecystectomy in situations with increased risk of Calot's components injury. We reported our experience with the patients treated with PC and reviewed the literature. Fifty-four patients with complex acute cholecystitis underwent PC, including conventional partial cholecystectomy (CPC; n = 48) and laparoscopic partial cholecystectomy (LPC; n = 6). The clinical diagnosis was verified by ultrasonography. In addition, we reviewed 1190 published cases (1972-2005) who underwent a "nonconventional" surgery for severe cholecystitis, including cholecystostomy, CPC, or LPC. Review of the literature, including our cases, showed a male:female ratio of 1.3:1. The major operative indication was severe acute cholecystitis. Procedures included cholecystostomy (65.8%) and PC (34.2%). In the follow-up (n = 1190), biliary leak (4.8%), retained stones (4.6%), recurrent symptoms (2.3%), wound infections (1.9%), persistent biliary fistula (0.9%), and prolonged biliary drainage (0.2%) were found, with an overall mortality rate of 9.4 per cent. In 133 patients, because of postoperative complications (e.g., recurrent symptoms, remaining common bile duct stones, or persistence of bile fistula), reoperation was necessary, including 121 cases (90.1%) of cholecystectomy, whereas the other 11 patients underwent other procedures such as common bile duct exploration or closure of the fistula. The surgical trend for complex acute cholecystitis treatment has been changed from only cholecystostomy to a spectrum of cholecystostomy, CPC, and LPC with the progressive increase of PC. The proportion of the LPC compared with CPC has also increased during recent years. It seems that PC is a safe procedure for treating complicated acute cholecystitis. Whether the indication and need for alternative techniques to standard cholecystectomy is changing should be evaluated in future studies.

Controlled-surgical education in clinical liver transplantation is not associated with increased patient risks

INTRODUCTION

A qualified surgical team is required to perform liver transplantation (LTX). Growing numbers of transplants at transplant centers and large variations of transplant frequencies make a continuous education to train young surgeons on this complex field of hepato-biliary surgery mandatory, both from the organizational and motivational point of view (job enrichment and professional growth). On the contrary, perioperative patient risk management is of major importance in surgical practice and given growing organizational concern in hospitals. A retrospective clinical study was performed to describe and evaluate the process of surgical training for orthotopic LTX. Patient risks associated with or caused by the education process in clinical LTX were analyzed.

METHODS

Perioperative patient data and details of surgical strategies were collected for 155 consecutive LTX carried out at a single center. Operative and follow-up data were correlated with the degree of surgical experience of the first operating surgeon. Two groups were defined. In group A, transplant surgeons with >30 personally performed LTXs (n = 3) and in group B, transplant fellows with >30 assistance in LTx (n = 3) performed the operations. All LTX operations were standardized based on modified piggyback technique described by Belghiti. Group B operations were performed under close supervision/assistance of the ''transplant surgeon.'' Selection of patients for exposure to surgical training was based on the pre-operative estimation of surgical difficulty. Operative time, blood loss, liver function, post-operative morbidity, and survival rate data were compared in both groups.

RESULTS

A total of 155 LTX were performed in 131 patients and were analyzed, and 106 operations (68.3%) were performed by group A and 49 operations (31.6%) were performed by transplant fellows under supervision (group B). No significant differences concerning mean patient age, distribution of type of disease, operating time, the Model for Endstage Liver Disease (MELD) score and frequency of category Child A, B and C were detected between groups. Overall post-operative complication rate was 21.9% (n = 34). Transplant surgeons and transplant fellows had 19.8% (n = 21) and 26.5% (n = 13) of complication rate, respectively (p > 0.05). Overall patients survival rate was 94% and 89% at 45 days for the patients operated in groups A and B, respectively (p > 0.05). Survival rate, blood loss, intraoperative transfusion requirements and operating time did not differ significantly between groups.

CONCLUSIONS

Liver transplantation requires team performance to minimize patient risks. Incidence of complications was associated with the severity of disease but not with the education process. It could be demonstrated that with careful patient selection and supervision of the transplant fellow with a more experienced surgeon, the results are equal to those obtained when the experienced transplant surgeon is the prime operator.

The role and value of sirolimus administration in kidney and liver transplantation

Enormous advancements in visceral transplantation have led to significant improvements in the quality of life of patients. However, despite these developments, the average graft half-life after transplantation has remained almost unchanged and chronic rejection is still considered a major problem. In this regard, more concerns have shifted to factors influencing long-term graft survival, patient survival, and quality of life. To achieve this goal, detrimental effects of immunosuppressive (IS) agents, which have deleterious influence on the quality of life and/or patient survival, should be reduced. In the course of recent years, the transplant community has worked on reducing these side effects by developing new ISs, employing new combination regimens, or finding and adjusting optimal dosages and blood level concentrations. Among the IS agents, the antifungal, antitumoral and IS activity of mammalian target of rapamycin (mTOR) inhibitors without nephrotoxicity, have received special attention regarding this new class of IS. Sirolimus (SRL), as the first member of mTOR inhibitors, has been utilized in many clinical trials with respect to its benefit-risk assessment. In our review, the clinical evolution of SRL, as well as the evidence-based clinical benefits of SRL in kidney and liver transplantation (KTx, LTx), are summarized. Various studies of SRL in KTx and LTx have shown that combination therapy with SRL will enrich the variety of IS modalities. It also can be regarded as a safe base therapy to which other necessary drugs can be added. In addition to the enhanced acute rejection prophylaxis, and in contrast to the calcineurin inhibitors (CNI) and steroids, this drug solely does not have common side effects such as nephrotoxicity, neurotoxicity, diabetes mellitus and hypertension. Moreover, this agent might diminish vasculopathic processes that mediate chronic allograft nephropathy (CAN). Therefore, by reducing the likelihood of CAN it can decrease the rate of long-term organ failure. One possibly desirable characteristic of SRL is its antiproliferative effect, which could provoke antitumoral or antiatherogenic activity following transplantation. Despite all promising impacts of SRL in organ transplantation, there are some concerns regarding the adverse effects of this drug, for instance dyslipidemia, pneumonitis and wound healing problems. However, the majority of these side effects can be reduced or ceased by careful dose adjustments and correct timing of use. In conclusion, after a decade of both in vivo and in vitro studies on SRL, it can be advocated that SRL is a promising, potent and effective IS agent as it reduces the rate of acute rejection episodes in de novo transplants. It could improve the quality of life, graft and patient survival rate, and achieve excellent outcomes with few adverse effects when wisely used in combination with other immunosuppressants.

Surgical Treatment of Patients with Wandering Spleen: Report of Six Cases with a review of the literature

Wandering spleen, which is defined as a spleen without peritoneal attachments, is a rare disease and a delay in the clinical and/or radiological diagnosis may lead to splenic torsion, infarction, and necrosis. Owing to the physiologic importance of the spleen, especially in children, and the risk of postsplenectomy sepsis, early diagnosis and splenopexy are recommended. In the present article, we describe the results of our management of this rare problem on six patients, and we review all available literature from 1895 to 2005. Briefly, our technique includes flap creation from parietal peritoneum and settlement of spleen in the fossa splenica. Free edges of this flap are stitched to the stomach and the left end of transverse colon and the beginning of the descending colon. The body of the stomach was stitched to the abdominal wall to prevent gastric volvulus, while the fundus region was fixed to the diaphragm to support the spleen. Finally, an omental patch was stitched to the intact abdominal wall above the flap. In conclusion, the procedure of splenopexy without using mesh is considered to be a safe and curative modality for wandering spleen without imposing any undue risk of infection or foreign material reaction.

Surgical strategies for liver transplantation in the case of portal vein thrombosis--current role of cavoportal hemitransposition and renoportal anastomosis

Portal vein thrombosis (PVT), a common complication of end stage liver disease, is no longer considered a definite contraindication for liver transplantation (LTx). The clinical decision to perform an LTx in the case of PVT depends on the degree of PVT and the experience of the surgeon. Eversion thromboendovenectomy was suggested by most authors as the surgical technique of choice for PVT grade 1, 2, and 3. If PVT obstructs more extended parts of the porto-mesenteric venous circulation, surgical options would include different types of venous jump graft reconstructions or arterialization of the portal vein. Combined liver and small bowel transplantation is another possible alternative. Cavoportal hemitransposition (CPHT) and renoportal anastomosis (RPA) were recently particularly advocated as creative surgical strategies in case of diffuse PVT. In this work, we focus on CPHT and RPA surgical techniques during LTx, which attempts to secure the portal flow to the liver graft in case of pre-existent diffuse PVT. We provide a review of all reported clinical experience at international clinical centers using these techniques. According to our meta-analysis a total of 15 studies were published on this topic between 1996 and 2005. In summary, a total of 56 orthotopic LTx have been performed in 53 patients (28 men, 25 women) combined with either CPHT or RPA, for the purpose of providing the donor graft with adequate inflow. Mean age was 44 yr including two patients who were infants, with the youngest recipient being two yr old. Main indications for LTx were liver cirrhosis caused by viral hepatitis, alcoholic cirrhosis and cryptogenic cirrhosis. CPHT was performed in 46 cases, and RPA in 10 cases. Thirty-five of 53 patients (66%) had surgery previous to LTx. Of these, 13 patients (37%) [corrected] presented with a history of other previous surgical procedures for decompression of portal hypertension or treatment of associated complications (portocaval shunts, splenectomy, etc). Ascites, renal dysfunction, lower extremity and torso edema and variceal bleeding were dominant post-operative complications after CPHT or RPA noted in 22 cases (41.5%), 18 cases (34%), 17 cases (32%) and 13 cases (24.5%) respectively. Patients' follow-up ranged from two to 48 months. Thirty nine of 53 patients [corrected] (74%) survived [corrected] and 14 patients died (26%) [corrected] during the course of observation. Based on the literature, we conclude that the ideal technique to overcome PVT during LTx is still controversial. Short-term follow-up results of both methods are promising, however, long-term results are unknown at present. Furthermore, clinical follow-up and basic experimental work is required to evaluate the influence of systemic venous inflow to the liver graft with respect to long-term liver function and liver regeneration.

Primary malignant hepatic epithelioid hemangioendothelioma: a comprehensive review of the literature with emphasis on the surgical therapy

Malignant hepatic epithelioid hemangioendothelioma (HEH) is a rare malignant tumor of vascular origin with unknown etiology and a variable natural course. The authors present a comprehensive review of the literature on HEH with a focus on clinical outcome after different therapeutic strategies. All published series on patients with HEH (n = 434 patients) were analyzed from the first description in 1984 to the current literature. The reviewed parameters included demographic data, clinical manifestations, therapeutic modalities, and clinical outcome. The mean age of patients with HEH was 41.7 years, and the male-to-female ratio was 2:3. The most common clinical manifestations were right upper quadrant pain, hepatomegaly, and weight loss. Most patients presented with multifocal tumor that involved both lobes of the liver. Lung, peritoneum, lymph nodes, and bone were the most common sites of extrahepatic involvement at the time of diagnosis. The most common management has been liver transplantation (LTx) (44.8% of patients), followed by no treatment (24.8% of patients), chemotherapy or radiotherapy (21% of patients), and liver resection (LRx) (9.4% of patients). The 1-year and 5-year patient survival rates were 96% and 54.5%, respectively, after LTx; 39.3% and 4.5%, respectively, after no treatment, 73.3% and 30%, respectively, after chemotherapy or radiotherapy; and 100% and 75%, respectively, after LRx. LRx has been the treatment of choice in patients with resectable HEH. However, LTx has been proposed as the treatment of choice because of the hepatic multicentricity of HEH. In addition, LTx is an acceptable option for patients who have HEH with extrahepatic manifestation. Highly selected patients may be able to undergo living-donor LTx, preserving the donor pool. The role of different adjuvant therapies for patients with HEH remains to be determined.

A regression model for correcting intraocular lens power after refractive surgery independent of preoperative data

PURPOSE

To find a method of calculating intraocular lens (IOL) power that may be independent of preoperative data in eyes that have previously undergone myopic laser in situ keratomileusis (LASIK).

METHODS

In 148 eyes of 75 patients, before and 6 months after LASIK, IOL power was calculated with SRK/T formula utilizing the spherical equivalent as the desired target refraction. Assuming that LASIK does not alter the crystalline lens refractive properties, IOL calculation error (CER) was estimated with this formula: CER = [pre-LASIK IOL power]/[post-LASIK IOL power]. Then the authors used postoperative biometry and Orbscan II corneal topography data in multiple regression models to find the best variables to predict the CER. Predicted amount of error which is calculated independent of preoperative data could be used to correct the post-LASIK calculated IOL: [corrected post-LASIK IOL power] = CER x [post-LASIK IOL power].

RESULTS

A regression model with these predictors was found: axial length in millimeters (L), radius of the anterior corneal surface best fitted sphere in millimeters divided by radius of the posterior corneal surface best fitted sphere in millimeters (AntBFS/PostBFS), corneal central 5 millimeters mean power in diopters divided by corneal central 3 millimeters mean power in diopters (mean 5 mm/mean 3 mm), the post-LASIK IOL power, and the post-LASIK simulated K reading. The model R square was 0.88.

CONCLUSIONS

There is correlation between post-LASIK biometry values and IOL power correction factor. This study presents a new model for further investigation.

Evaluation of microperfusion disturbances in the transplanted liver after Kupffer cell destruction using GdCl3: an experimental porcine study

BACKGROUND

Organ function after liver transplantation is determined by ischemia-reperfusion injury. Destruction of Kupffer cells with gadolinium chloride (GdCl3) has been shown to have a possible preventive effect on the extent of this injury, which can be extrapolated by analyzing the distribution of hepatic microperfusion. The aim of this study was to evaluate the protective effect of GdCl3 on disturbances of microperfusion in the transplanted liver.

METHODS

Landrace pigs were randomly divided into three groups. In the control group (CG; n=6) a mapping of the native liver was conducted. For mapping, the four hepatic liver lobes were named from right to left with A to D and every lobe was divided into three vertical segments (cranial, medial, and caudal). In each of these 12 areas, microperfusion was quantified using a thermodiffusion probe (TD [mL/100 g/min]). The other two groups were considered as transplanted treated group (TTG; n=10) and transplanted nontreated group (TnTG; n=10). The TTG received an infusion of 20 mg/kg GdCl3 intravenously 24 hours before organ harvesting. Then standardized orthotopic liver transplantation was performed. In TnTG, standardized orthotopic liver transplantation was carried out without prior GdCl3 injection. In the recipients, the microperfusion of transplanted livers were mapped in both TnTG and TTG, in two different time points (1 hour [n=5] and 24 hours (n=5]) after reperfusion.

RESULTS

A significant reduction of macrophages in the TTG livers in comparison to the CG and TnTG livers was observed (P<.05). However, the number of macrophages in CG and TnTG livers showed no significant difference (P>.05). Regarding liver microperfusion, in TnTG, a marked heterogeneity was detected in the livers after reperfusion. Significant differences between liver lobes (horizontal planes; P=.032) and vertical layers of intralobar liver parenchyma (P=.029) were observed. The same pattern was seen in TTG livers after reperfusion and a significant difference between horizontal (P=.024) and vertical layers (P=.018) of liver tissue were observed. Comparing intralobar regional flow data between vertical planes 24 hours after reperfusion still showed a prominent variation of hepatic tissue perfusion in TnTG livers (P=.028). Within the same horizontal layers, no significant differences between lobes were measured anymore (P=.16). Contrary to TnTG, in TTG, a homogenous pattern of regional liver tissue perfusion was recorded 24 hours after reperfusion. Comparison of TD data on the liver regions showed no significant microperfusion differences in either horizontal (P=.888) or vertical (P=.841) layers.

CONCLUSIONS

Application of GdCl3 resulted in a significant reduction of Kupffer cells. Twenty four hours after transplantation microperfusion showed a homogeneous pattern, which constituted an earlier and better recovery of the transplanted liver. Therefore, destruction of Kupffer cells reduced ischemia-reperfusion injury and seemed to be responsible for the early recovery of microperfusion disturbances and thus for an improvement of graft function.

Development and evaluation of a training module for the clinical introduction of the da Vinci robotic system in visceral and vascular surgery

BACKGROUND

With the increasing use of the surgical robotic system in the clinical arena, appropriate training programs and assessment systems need to be established for mastery of this new technology. The authors aimed to design and evaluate a clinic-like training program for the clinical introduction of the da Vinci robotic system in visceral and vascular surgery.

METHODS

Four trainees with different surgical levels of experience participated in this study using the da Vinci telemanipulator. Each participant started with an initial evaluation stage composed of standardized visceral and vascular operations (cholecystectomy, gastrotomy, anastomosis of the small intestine, and anastomosis of the aorta) in a porcine model. Then the participants went on to the training stage with the rat model, performing standardized visceral and vascular operations (gastrotomy, anastomosis of the large and small intestines, and anastomosis of the aorta) four times in four rats. The final evaluation stage was again identical to the initial stage. The operative times, the number of complications, and the performance quality of the participants were compared between the two evaluation stages to assess the impact of the training stage on the results.

RESULTS

The operative times in the final evaluation stage were considerably shorter than in the initial evaluation stage and, except for cholecystectomies, all the differences reached statistical significance. Also, significantly fewer complications and improved quality for each operation in the final evaluation stage were documented, as compared with their counterparts in the initial evaluation stage. These improvements were recorded at each level of experience.

CONCLUSIONS

The presented experimental small and large animal model is a standardized and reproducible training method for robotic surgery that allows evaluation of the surgical performance while shortening and optimizing the learning-curve.

Surgical treatment of primary hepatic epithelioid hemangioendothelioma

Epithelioid hemangioendothelioma is a very rare tumor of vascular origin. It can develop in different tissues such as soft tissue, lung, or liver. Hepatic epithelioid hemangioendothelioma (HEH) mostly affects females. The malignant potential of HEH often remains unclear in the individual patient. It can range from benign hemangioma to malignant hemangioendotheliosarcoma. Here we present our experience with five patients with primary HEH, who were treated with curative intention in our department. All patients in our series with confirmed histological HEH did not show extrahepatic extension and consequently underwent surgical treatment. In three patients, liver transplantation (LTx) was performed (two cadaveric and one living related). In one patient, a right-sided hemihepatectomy with partial resection of the diaphragm was performed. One patient died while she was on the waiting list for LTx due to rapid tumor progression. Postoperative follow-up ranged from 1 to 13 years. No adjuvant chemotherapy was applied. Until now, no recurrence of local tumor or distant metastases could be observed during follow-up in our series. Early detection and surgical intervention in case of HEH can potentially offer curative treatment. The treatment of first choice appears to be radical liver resection. In our view, LTx represents a potentially important option for patients with a nonresectable tumor. Despite the long waiting time, its often unclear dignity, and a proven progressive growth pattern, living related LTx also plays a potentially important role. The 5-year overall survival rate of patients with HEH in the literature varies from 43% to 55%. Long-term survival of patients with HEH is significantly higher compared to other hepatic malignancies. The role of adjuvant therapy currently remains unclear.

Guidelines for prevention and management of complications following kidney transplantation in rats

Kidney transplantation in rats is a useful model for microsurgery, transplantation, and immunology studies. Our aim was to analyze various techniques of kidney transplantation in rats with emphasis on guidelines for the prevention and management of complications. Complications were categorized into general, vascular, and urological types and respectively attributed to long transplantation time, core body temperature drop, nonreplaced intraoperative blood loss, anastomosis failure, and ureteral anastomoses with stents or cannulas, which increase the risk of calculus formation. In conclusion, to decrease the complication rates the animal should be placed on a heating pad. For hemodynamic stability NaCl should be administered subcutaneously. To reduce the risk of thrombosis, ice-cold saline containing heparin should be administered. Vascular complications, which mainly depend on the microsurgeon's expertise, can be prevented by meticulous surgical technique (preferably an end-in-end anastomosis). The main urinary complications can be minimized by avoiding stents and cannulas and focusing on using techniques like the bladder-patch technique.

Indications for Liver Transplantation in Patients with Amyloidosis: A Single-Center Experience with 11 Cases

Familial amyloidotic polyneuropathy (FAP) is an inherited disorder with the systemic deposition of amyloid fibrils containing mutant transthyretin variants. The mutant form of transthyretin amyloidosis is produced mainly in the liver. Successful liver transplantation (LTx) could eliminate the source of the variant transthyretin molecule, and is now the only known curative treatment. The aim of this study is to evaluate the results of LTx for FAP at the University of Heidelberg. Eleven patients who underwent LTx between 1985 and 2004 with the diagnosis of FAP were evaluated. Of 11 patients, seven (64%) were male and four (36%) were female. The mean age was 49.5 years (range 27-70). Met 30 (n=5) was the most common type of amyloidosis followed by Arg 50 (n=3), Val 107 (n=2), and Phe 33 (n=1). All of the patients were selected for LTx and Domino LTx was performed in six patients. The majority (80%) of the patients with type Met 30 amyloidosis are alive, whereas in other types of amyloidosis only 33% are living. This finding emphasizes better prognosis of Met 30 variant of FAP in comparison to other variants such as Arg 50, Val 107, and Phe 33. After LTx, improvement of clinical symptoms (completely or partially) was observed in six patients (55%). In conclusion, LTx is considered as the only therapeutic alternative in patients with amyloidosis accompanied by hepatic synthesis of the amyloid protein. The most important risk factors for LTx can be predicted by assessing the nutritional condition of the patient, the duration of the disease, and the amyloid variant. Therefore, precise diagnostic measures are required before listing a patient for LTx. Domino LTx is an acceptable form of LTx that can preserve the pool of organ donors. In order to stop the progression of FAP, LTx would be justified in a subgroup of patients with amyloidosis. Based on our results, we support the idea that the effectiveness of extended preoperative period before LTx or the transplantation of other transthyretin variants other than Met 30 is questionable.

Negative impact of systemic catecholamine administration on hepatic blood perfusion after porcine liver transplantation

Catecholamines are often administered during and after liver transplantation (LTx) to support systemic perfusion and to increase organ oxygen supply. Some vasoactive agents can compromise visceral organ perfusion. We followed the hypothesis that the vasculature of transplanted livers presents with a higher sensitivity, which leads to an increased vulnerability for flow derangement after application of epinephrine (Epi) or norepinephrine (NorEpi). Hepatic macroperfusion and microperfusion during systemic Epi or NorEpi infusion were measured by Doppler flow and thermodiffusion probes in porcine native, denervated, and transplanted livers (n = 16 in each group). Epi or NorEpi were infused (n = 8 in each subgroup) in predefined dosages (low dose = 5 microg/kg/minute and high dose = 10 microg/kg/minute) over 240 minutes. Systemic cardiocirculatory parameters were monitored continuously. Hepatic perfusion data were compared between all groups at comparable time points and dosages. In all native, denervated, and transplanted liver groups, Epi and NorEpi induced an inconsistent rise of mean arterial pressure and heart rate shortly after onset of infusion in both dosages compared with baseline. No significant differences of cardiovascular parameters at comparable time points were observed. In native livers, Epi and NorEpi induced only temporary alterations of hepatic macrocirculation and microcirculation, which returned to baseline 2 hours after onset of infusion. No significant alterations of hepatic blood flow were detected after isolated surgical denervation of the liver. By contrast, transplanted livers showed a progressive decline of hepatic macrocirculation (33-75% reduction) and microcirculation (39-58% reduction) during catecholamine infusions in a dose-dependent fashion. Characteristics of liver blood flow impairment were comparable for both vasoactive agents. In conclusion, pronounced disturbances of hepatic macrocirculation and microcirculation were observed during systemic Epi and NorEpi infusion after LTx compared with native and denervated livers. Microcirculation disturbances after LTx might be explained by impairment of hepatic blood flow regulation caused by an increased sensitivity of hepatic vasculature after ischemia-reperfusion and by lengthening of vasopressor effects caused by reduced hepatocyte metabolism. Clinicians should be aware of this potentially hazardous effect. Therefore, application of catecholamines after clinical LTx should be indicated carefully.

A review of various techniques of orthotopic liver transplantation in the rat

Orthotopic liver transplantation (OLT) in rat is a demanding procedure, which has become a popular model to investigate various problems. Our aim was to review and analyze the various techniques of experimental OLT in the rat. A review of the literature revealed 30 techniques or technical modifications. Each modification represented a change or a simplification of the reconstruction method of five anatomical structures, which are cornerstones of a successful OLT: the suprahepatic inferior vena cava (SHVC), portal vein (PV), infrahepatic inferior vena cava (IHVC), hepatic artery (HA), and bile duct (BD). SHVC is anastomosed via microsuture or cuff. The PV anastomosis is performed by microsuture, cuff, or a microsuture-temporary splint technique. IHVC is reconstructed by a microsuture, cuff, or microsuture-temporary splint technique. Arterialization has been accomplished via microsuture (aortic segment, celiac segment, or aortic patch), cuff, splint, sleeve, or telescopic method. Nonarterialization of the graft has also been described. Methods for BD reconstruction include pull-through, telescopic, splint, and T-tube. Although a high level of microsurgical skill is the basic requirement in the microsuture technique which provides the most physiological situation and concomitantly reduces thrombosis, it increases anhepatic time compared to the cuff procedure. The learning curve of microsuture techniques is flat; beginners need much practice to become expert. The most physiologic techniques for anastomoses are preferred for long-term survival studies, while the faster techniques are options for short-term survival studies. Each research group must choose techniques according to study defined aims.

Robot-assisted abdominal surgery

BACKGROUND

Robotic assistance or telemanipulation is the latest technological advance in minimally invasive surgery. Its future implementation will depend on the advantages that it can provide over standard laparoscopy or open surgery.

METHODS

All Medline-cited papers (from case reports to reviews) about telemanipulators used in visceral surgery were assessed. The data in each paper were analysed to enable an up-to-date review of robot-assisted abdominal surgery by the most advanced telemanipulator (da Vinci).

RESULTS

Most papers presented case series demonstrating the feasibility of robotic technology in performing a specific procedure. Comparative studies of robot-assisted surgery versus standard laparoscopic or open surgery were usually matched cohort studies. They generally showed an increased operating time for robot-assisted procedures but with similar rates of conversion, intraoperative and postoperative complications, and mortality in comparison to those of laparoscopic surgery. Consistent long-term follow-up data were missing and only one randomized clinical trial was conducted.

CONCLUSION

Robot-assisted surgery appears safe and feasible for certain standard surgical procedures. However, at its current level of development, it offers no clear, significant advantage over standard laparoscopic techniques.

Different impact of normo- and hypotensive brain death on renal macro- and microperfusion--an experimental evaluation in a porcine model

BACKGROUND

Despite the growing use of kidneys from living donors, organs harvested from brain dead donors are the dominant graft types used in renal transplantation. It is accepted that brain death (BD) has a damaging effect on the renal allograft, with a lower graft survival. Amongst various causes, changes in renal microperfusion could be responsible. Renocortical microperfusion was assessed during BD using thermal diffusion in a porcine model.

METHODS

Two types of BD were induced in two groups of pigs [hypotension (Hypo-BD): n = 11; normotension (Normo-BD): n = 10] and compared to controls (n = 5) over a period of 210 min. We analysed systemic parameters [heart rate (HR), mean arterial blood pressure (MAP)], aortic blood flow (ABF) and renal perfusion [renal artery blood flow (RABF) and renocortical blood flow (RCBF)].

RESULTS

Following the two distinct forms of BD induction, a stable normo- or hypotension was observed. Haemodynamic parameters were only slightly changed (control group: MAP, 62+/-2 mmHg; HR, 95+/-3/min; Normo-BD: MAP, 56+/-4 mmHg; HR, 104+/-8/min; Hypo-BD: MAP, 43+/-3 mmHg; HR, 112+/-7/min). Solely dependent on systemic haemodynamics, RABF and RCBF decreased in the Hypo-BD (RABF: 142+/-19 to 94+/-9 ml/100 g/min; RCBF: 80+/-4 to 52+/-2 ml/100 g/min), while in Normo-BD group RABF mildly changed (158+/-13 ml/100 g/min) and RCBF decreased slightly from 76+/-3 to 70+/-6 ml/100 g/min. As opposed to the Normo-BD group, animals with Hypo-BD showed a significant decrease in RABF (reduction of 34%) and RCBF (reduction of 35%) with a sharp drop of MAP (reduction of 25%), however ABF remained relatively constant.

CONCLUSIONS

In this model, a reduction of renocortical microperfusion in brain dead pigs was only found during haemodynamic instability (hypotension) and could not be attributed to BD as such. Our findings would support intensive cardiocirculatory stabilization for potential BD donors in order to minimize kidney preservation damage.

Long-term results of paediatric kidney transplantation at the University of Heidelberg: a 35 year single-centre experience

BACKGROUND

Kidney transplantation remains the most effective treatment for children with end-stage renal disease. We analysed data from the University of Heidelberg transplant programme to present our results on paediatric kidney transplantations over the past 35 years.

METHODS

From 1967 to 2003, 354 paediatric kidney transplantations were performed at the University of Heidelberg. Data were obtained from the paediatric kidney transplantation records consisting of 291 (82%) cadaveric and 63 (18%) living donated transplants. Demographic data, family relationship of the living donors, surgical technique, immunosuppressive drugs, graft and patient survival rates were assessed.

RESULTS

The mean age of cadaveric and living donors was 32.0+/-17.1 and 37.6+/-7.5 years, respectively. The family relationship of the living donors included the mother in 65% of cases, the father in 31%, and other relatives in 4%. In the last 4 years, the respective mean cold ischaemia time was 1.6+/-0.5 h for living donated and 13.5+/-4.1 h for cadaveric donors. The mean age of children who received kidneys from cadaveric and living donors was 11.3+/-4.5 and 10.4+/-4.5 years, respectively, with a male to female ratio of 57 to 43%. Overall patient survival rates were 95% after 1 year and 89% after 5 years. The patient 5 and 10 year survival rates for living donor renal transplantations were 95 and 95%, respectively. Graft survival rates improved since 1990 compared with the period prior to 1990: 82.5 vs 56.7% graft survival at 1 year and 82.5 vs 50% after 5 years (P = 0.03). Comparing the operating technique in a subgroup of our patients that received the same immunosuppressive regimen, anastomoses with the aorta and vena cava (51%, n = 31) were associated with a graft survival of 86.6 and 83.3% after 1 and 5 years, whereas anastomoses with iliac vessels (49%, n = 30) were associated with a graft survival of 55.8 and 51.6% after 1 and 5 years, respectively (P = 0.01).

CONCLUSIONS

There has been a gradual improvement in our paediatric kidney transplantation results over time. Living donor paediatric kidney transplants have higher patient and better graft survival rates than cadaveric donor kidney transplants. Using the aorta and inferior vena cava for graft anastomosis, utilizing newer immunosuppressive drugs and implementing living kidney donation have positively affected the results of our paediatric kidney transplantations.

Results of renal transplantation using kidneys harvested from living donors at the University of Heidelberg

BACKGROUND

Although a majority of patients undergoing renal transplantation currently receive a cadaver kidney, living donors continue to be an important source of transplanted kidneys. Recipients of living donor kidneys demonstrate improved graft survival. To expand the pool of suitable organ donors an organ procurement programme of living donors has been developed over the past 35 years. We have reviewed our living donor nephrectomy experience over this period to analyse the donor and recipient peri- and postoperative morbidity and mortality rate.

METHODS

We reviewed the operative complications and the long-term outcome of 219 living donated kidney transplantations before and after introduction of cyclosporine A. Donor and graft complications as well as recipient complications and survival rate were investigated. Additionally, the findings of 16 laparoscopically operated living donors were compared to a group of 20 patients who underwent a conventional surgery.

RESULTS

The overall recipient 3 and 5 year survival rates in the cyclosporine A era were 95 and 94%, respectively. Prior to the introduction of cyclosporine A, the overall recipient survival rates at 3 and 5 years were 84 and 84%, respectively. The overall graft survival rates were 92 and 85% for the cyclosporine A era compared to 68 and 60% before introduction of cyclosporine A, at 3 and 5 years, respectively. The patient and graft survival rate in the cyclosporine group were significantly higher than in the pre-cyclosporine group (log-rank: P = 0.0107 and P = 0.0003, respectively). Donor complications included pain at the incision site (35%), mild hypertension (27%), proteinuria (19%), urinary tract infections (11%), pneumothorax (5%), blood transfusion (3.5%) and wound infection (3%), with no mortalities. Our results showed a longer duration of operation, and longer warm ischaemia and cold ischaemia times in laparoscopically operated living donors than those that were seen in the conventional approach. There was no statistically significant difference in complications between both techniques. However, the hospitalization days and usage of analgesic medication in laparoscopy donors were lower than in the conventional approach.

CONCLUSIONS

Similar to previous studies the results of the present analysis confirm an increase in patient and graft survival rates in the cyclosporine era compared to before its usage. Living donor nephrectomy, done through a conventional or laparoscopic approach, remains a valuable source of kidneys for transplantation with low complication rates.

Endonasal endoscopic resection of ethmoido-orbital osteoma compressing the optic nerve

Osteomas are the most common benign tumors of the paranasal sinuses. Open procedures for removal of ethmoid osteomas have been the method of choice, but debate over optimal treatment continues. We report resection of a large ethmoido-orbital osteoma via endonasal endoscopic approach with minimal morbidity. A 42-year-old man presented with a 1-year history of slowly progressive proptosis and lateral gaze diplopia. Imaging studies of orbits and sinuses revealed a large bony mass in left ethmoid sinus extending into the left orbit. The mass had compressed and slightly diverted the optic nerve. The patient had also bilateral extensive polyposis for which bilateral ethmoidectomy and sphenoidotomy were performed. Using a curved blunt elevator, the osteoma was gently and meticulously detached from adjacent structures. Finally, frontal recesses were cleaned form the polyps. The postoperative period was uneventful. After 18 months, he is still free of symptoms. The previously used management modality of symptomatic osteomas has mostly consisted of open approaches. Endonasal endoscopic approach provides a safe and effective alternative to open approaches, offering cosmetic advantages and lowering the morbidity. This approach could be judiciously used in large ethmoido-orbital osteomas in selected cases.

Circulatory and respiratory complications of carbon dioxide insufflation

BACKGROUND

Although providing excellent outcome results, laparoscopy also induces particular pathophysiological changes in response to pneumoperitoneum. Knowledge of the pathophysiology of a CO(2) pneumoperitoneum can help minimize complications while profiting from the benefits of laparoscopic surgery without concerns about its safety.

METHODS

A review of articles on the pathophysiological changes and complications of carbon dioxide pneumoperitoneum as well as prevention and treatment of these complications was performed using the Medline database.

RESULTS

The main pathophysiological changes during CO(2) pneumoperitoneum refer to the cardiovascular system and are mainly correlated with the amount of intra-abdominal pressure in combination with the patient's position on the operating table. These changes are well tolerated even in older and more debilitated patients, and except for a slight increase in the incidence of cardiac arrhythmias, no other significant cardiovascular complications occur. Although there are important pulmonary pathophysiological changes, hypercarbia, hypoxemia and barotraumas, they would develop rarely since effective ventilation monitoring and techniques are applied. The alteration in splanchnic perfusion is proportional with the increase in intra-abdominal pressure and duration of pneumoperitoneum.

CONCLUSION

A moderate-to-low intra-abdominal pressure (<12 mm Hg) can help limit the extent of the pathophysiological changes since consecutive organ dysfunctions are minimal, transient and do not influence the outcome.

Correlation of cephalic anthropometric parameters and microsurgical anatomy of the optic nerves: a cadaveric morphometric study

BACKGROUND

This study was designed to elucidate the possible correlation of cranial anthropometric measurements with the chiasm to limbus sphenoidale distance to facilitate preoperative estimation of this distance and to choose a better surgical approach.

METHODS

Thirty-three fresh adult cadaver heads (22 males and 11 females) were evaluated for cranial anthropometric measurements. The precraniotomy anthropometric measurements included (A) inion to nasion distance and (B) the longest intermeatal meridian. Subsequently, with a standard craniotomy, the following intervals were measured: (C) optic chiasm to falciform ligament, (D) anterior aspect of optic chiasm to limbus sphenoidale, and (E) limbus sphenoidale to inner nasion. A combined ratio parameter, labeled as (F), was calculated from the following equation: F = B/E x 10.

RESULTS

The mean values and standard errors of the mean of parameters A to F were 195.8 +/- 14.53 mm, 374.7 +/- 25.29 mm, 10.47 +/- 1.89 mm, 9.93 +/- 2.01 mm, 38.46 +/- 3.17 mm, and 9.81 +/- 1.11, respectively. The parameter D had significant correlation to the parameters B, C, E, and F. The most significant correlation was seen between parameters D and F (p < 0.001). According to linear regression assessment between parameters D and F, the following regression equation was obtained: D = 4.24 + 0.58F.

CONCLUSIONS

Optic nerve topography and dimensions show inter-personal variations that may be anticipated to some extent with cranial anthropometric data. Calculating of F ratio gives us an acceptable estimation of the actual distance of chiasm to limbus sphenoidale, which in turn can help the surgeon to select the approach to tumors of intrasellar region. However, the role of meticulous imaging studies cannot be overemphasized to confirm the anticipated estimations.

Cerebral phaeohyphomycosis masquerading as a parafalcian mass: case report

BACKGROUND

Cerebral phaeohyphomycosis caused by Fonsecaea pedrosoi is a rarity. However, about four cases have been reported in the literature. The disease remains mostly fatal despite employment of new treatment modalities.

CASE

An 18-year-old boy presented seizures of recent onset. Two years back, he developed cutaneous phaeohyphomycosis after a splinter scratch on his chest wall. Imaging revealed a contrast enhancing parafalcian solid mass. Right frontal parasagittal craniotomy was performed and the lesion resected as much as possible, followed by IV amphotericin B and oral itraconazole treatment. The patient has been doing well during a 15-month follow-up period.

DISCUSSION

Cerebral phaeohyphomycosis is an extremely rare lesion, which could masquerade as a parafalcian mass. Radical surgical removal together with antimicrobials remains the cornerstone treatment of cerebral phaeohyphomycosis.

Endoscopic resection of nasopharyngeal angiofibromas by combined transnasal and transoral routes

PURPOSE

To determine the role of endoscopic surgery in decreasing intraoperative bleeding, morbidity, and hospitalization period of juvenile nasopharyngeal angiofibroma resection and to describe combined endoscopic transnasal and transoral approaches.

PATIENTS AND METHODS

Twelve cases of juvenile nasopharyngeal angiofibroma diagnosed by endoscopic examination, computed tomography, and angiography were selected for endoscopic resection. Tumor staging ranged from stage I(A) to II(B). Ten patients underwent preoperative selective arterial embolization, and in 1 case selective arterial ligation was used. In general, the tumors were approached endoscopically through nasal and oral cavities with 0 degrees and 30 degrees 4-mm telescopes without any incision and no packing at their termination.

RESULTS

The patients were followed by endoscopy and computed tomography. There was a dramatic decrease in intraoperative bleeding and postoperative morbidity. No early postoperative complications were seen. Two recurrences were observed in 12 patients up to a mean follow-up of 15 months.

CONCLUSIONS

Minimal bleeding, decreased morbidity, and shorter hospitalization period were the main reasons that prompted us to use endoscopic technique for the removal of juvenile nasopharyngeal angiofibroma. Adding transoral endoscopic approach to the transnasal endoscopic approach provides 2-sided exposure and appreciate access to angiofibroma.