Diverticulopexy and cricopharyngeal myotomy: treatment for the high-risk patient with a pharyngoesophageal (Zenker's) diverticulum

Although diverticulopexy for the treatment of Zenker's diverticulum was described more than 75 years ago, its use has been infrequently reported in the surgical literature. Between 1974 and 1987, thirty-two patients manifested dysphagia caused by a pharyngoesophageal diverticulum. Twelve patients underwent diverticulopexy with cricopharyngeal myotomy, whereas the others had a one-stage resection of the diverticulum with myotomy. Complications of diverticulectomy were rare, but included an instance of esophageal leak, which responded to conservative therapy. Despite this low complication rate, diverticulopexy with myotomy was used in patients who possessed risk factors that made them unsuitable candidates for diverticulectomy. These factors included a debilitated state from effects of the diverticulum, a history of postsurgical complications, multiple medical illnesses, advanced age with inability to ambulate, and insulin-dependent diabetes mellitus. A nasogastric tube was not necessary after diverticulopexy. This allowed oral intake on the first postoperative day, immediate ambulation, and a shorter hospital stay. Objective recurrence occurred in one patient who underwent diverticulopexy and myotomy caused by manipulation of the sac during a subsequent surgical procedure, but significant dysphagia did not occur. Thus, although diverticulectomy has proved to be a relatively safe procedure, diverticulopexy with cricopharyngeal myotomy is recommended for high-risk patients in whom potential complications from diverticulum excision and prolonged hospitalization could be devastating.     

Transurethral incision of urethral diverticulum in the female

A new technique of transurethral incision of urethral diverticulum was successfully used in two women. The method described is safe, simple and shortens operating time.     

Monitoring pulmonary perfusion by electrical impedance tomography: an evaluation in a pig model

Background: Electrical impedance tomography (EIT) is a non-invasive technique that generates images of impedance distribution. Changes in the pulmonary content of air and blood are major determinants of thoracic impedance. This study was designed to evaluate EIT in monitoring pulmonary perfusion in a wide range of cardiac output.
Methods: Eight anaesthetised, mechanically ventilated pigs were fitted with a 16-electrode belt at the mid-thoracic level to generate EIT images that were analysed to determine pulse-synchronous systolic changes in impedance (Δ Z _sys). Stroke volume (SV) was derived using a pulmonary artery catheter. Reductions in cardiac pre-load, and thus pulmonary perfusion, were induced either by inflating the balloon of a Fogarty catheter positioned in the inferior caval vein or by increasing the positive end-expiratory pressure (PEEP). All measurements were performed in a steady state during a short apnoea.
Results: Pulse-synchronous changes in Δ Z _sys were easily discernable during apnoea. Balloon inflation reduced SV to 36% of the baseline, with a corresponding decrease in Δ Z _sys to 45% of baseline. PEEP reduced SV and Δ Z _sys to 52% and 44% of the baseline, respectively. Significant correlations between SV and Δ Z _sys were demonstrated during all measurements (ρ=0.62) as well as during balloon inflation (ρ=0.73) and increased PEEP (ρ=0.40). A Bland–Altman comparison of relative changes in SV and Δ Z _sys demonstrated a bias of −7%, with 95% limits of agreement at −51% and 36%.
Conclusions: EIT provided beat-to-beat approximations of pulmonary perfusion that significantly correlated to a wide range of SV values achieved during both extra and intrapulmonary interventions to change cardiac output.     

Is the search for Meckel's diverticulum in appendectomy still a current problem in common surgical practice?

During a ten year period from 1978 to 1988, 46 Meckel's diverticula (MD) were removed from patients with clinical symptoms of appendicitis. These were detected incidentally among 3230 appendectomies which were routinely followed by small bowel exploration. Only 45.6% had histopathologically inconspicuous diverticular mucosa. 17.4% of MD displayed pathological mucosal changes in the face of a normal appendix. In 10 patients both conditions co-existed. There were no postoperative deaths. Postoperative complications requiring operative revision occurred in one patient. The search for a MD should be routine, and not only consequence of finding a normal appendix. The rationale for the routine removal of a MD is not only its role as a potential risk factor and the lesser operative risk, but the fact that a macroscopically bland diverticulum reveals histopathological abnormalities considerably more often than commonly assumed.     

Transurethral incision and fulguration of the bladder diverticulum: radicality and clinical efficacy]

We performed transurethral incision and fulguration of the bladder diverticulum (TUIFBD) for 8 diverticula in 6 patients. In combination with TUIFBD, one patient received transurethral resection of the prostate and another one transurethral lithotripsy of bladder stones. TUIFBD has been easily performed without any operative complications. All 8 diverticula had shrunken from one to two months after the operation but only one diverticulum had disappeared. Symptoms related to the bladder diverticulum had disappeared postoperatively in all cases. In conclusion, TUIFBD can be easily and safely performed in combination with other transurethral surgical procedures. TUIFBD may be insufficient for radicality, but is clinically effective.     

Comparison of ultrasonic suture welding and traditional knot tying in a rabbit rotator cuff repair model

The purpose of this study is to evaluate ultrasonic suture welding of monofilament suture in an animal model of rotator cuff repair with biomechanical and histologic analyses. We randomly assigned 46 shoulders in 23 rabbits to 1 of 3 treatment groups: sham-operated (n = 15), knotted (n = 15), and welded (n = 16). Supraspinatus defects were surgically created and acutely repaired with suture anchors loaded with either No. 2-0 Ethibond for knotted group or No. 2-0 nylon for welded shoulders. Eighteen weeks postoperatively, all animals were killed, and the shoulders underwent either biomechanical testing or histologic analysis. The maximum stress of the sham-operated group (20.6 N/mm2) was significantly greater than that of both the knotted (10.2 N/mm2) and welded (8.3 N/mm2) groups (P < .05), but no differences were observed between the knotted and welded groups. Although some histologic changes were noted, none was considered to be significant to distinguish either group.     

Comparison of HTK- and UW-solution for liver preservation tested in an orthotopic liver transplantation model in the pig

The aim of this experimental study was to compare the preservation potency of University of Wisconsin (UW) and HTK (Bretschneider) solutions in an orthotopic liver transplantation (OLT) model in pigs. Livers were harvested using an in situ perfusion technique, where organs were flushed with the solution being tested, stored on ice — cold storage (CS) — for 2 or 24 h and then transplanted. Parameters monitored were liver enzymes in serum, hepatic water content, high energy phosphates, nuclear magnetic resonance (NMR) relaxation time T2, light microscopy and bile production. CS for 24 h is an extreme in pig liver preservation and is not compatible with animal survival. Biopsies showed drastic morphological changes and grafts did not produce bile in either group. (Bile production 2 h CS: HTK, 5.6 ± 1.8 ml/h; UW, 4.7 ± 2.3 ml/h) Enzyme release after reperfusion (ASGOT, ?LDH) was higher in long-term preservation. Hepatic tissue water content significantly decreased during CS in UW preserved livers. Edema alter reperfusion (?H₂0: HTK 24 h = + 5.6%, UW 24 h= + 4.8%) and regeneration capacity after reperfusion (UW 2 h = 63%, HTK 2 h = 55%, UW 24 h = 30%, HTK 24 h = 30%) were not significantly different. However, we did not observe major differences in preservation potency between the solutions tested. Differences were correlated, rather, with length 9 time of CS, than with the solution used. Therefore, HTK solution seemed to be a low potassium containing alternative to UW solution.     

Experimental electrical stimulation of the bladder using a new device

Summary Repeated bladder contractions were evoked during a six month period in three unanaesthetized female minipigs by using unipolar carbon fiber electrodes embedded in the bladder wall adjacent to the ureterovesical junction. In contrast to bipolar and direct bladder muscle stimulation unipolar electrodes at each ureterovesical junction evoked bladder pressure increase similar to those produced in previous investigations in dogs. Sacral nerve stimulation of S₂ evoked bladder contraction at a minimal current. Microscopic examination revealed no cellular reactions to the carbon fibers but a subcutaneous reaction to the receivers was seen and was thought to be due to mechanical irritation. The clinical implication of the findings is discussed.     

A modular magnetic anastomotic device for minimally invasive digestive anastomosis: proof of concept and preliminary data in the pig model

Background

The aim of our study was to assess the feasibility of minimally invasive digestive anastomosis using a modular flexible magnetic anastomotic device made up of a set of two flexible chains of magnetic elements. The assembly possesses a non-deployed linear configuration which allows it to be introduced through a dedicated small-sized applicator into the bowel where it takes the deployed form. A centering suture allows the mating between the two parts to be controlled in order to include the viscerotomy between the two magnetic rings and the connected viscera.

Methods and procedures

Eight pigs were involved in a 2-week survival experimental study. In five colorectal anastomoses, the proximal device was inserted by a percutaneous endoscopic technique, and the colon was divided below the magnet. The distal magnet was delivered transanally to connect with the proximal magnet. In three jejunojejunostomies, the first magnetic chain was injected in its linear configuration through a small enterotomy. Once delivered, the device self-assembled into a ring shape. A second magnet was injected more distally through the same port. The centering sutures were tied together extracorporeally and, using a knot pusher, magnets were connected. Ex vivo strain testing to determine the compression force delivered by the magnetic device, burst pressure of the anastomosis, and histology were performed.

Results

Mean operative time including endoscopy was 69.2 ± 21.9 min, and average time to full patency was 5 days for colorectal anastomosis. Operative times for jejunojejunostomies were 125, 80, and 35 min, respectively. The postoperative period was uneventful. Burst pressure of all anastomoses was ≥110 mmHg. Mean strain force to detach the devices was 6.1 ± 0.98 and 12.88 ± 1.34 N in colorectal and jejunojejunal connections, respectively. Pathology showed a mild-to-moderate inflammation score.

Conclusions

The modular magnetic system showed enormous potential to create minimally invasive digestive anastomoses, and may represent an alternative to stapled anastomoses, being easy to deliver, effective, and low cost.     

Comparison of pharyngoesophageal segment pressure in total laryngectomy patients with and without pharyngeal neurectomy

BACKGROUND: To compare pharyngoesophageal segment (PES) pressure values in total laryngectomy patients with and without pharyngeal neurectomy (PN) in the early postoperative period. METHODS: Forty-five previously untreated laryngeal carcinoma patients were enrolled into this prospective randomized study. Twenty of them underwent total laryngectomy with PN, and 25 underwent total laryngectomy without PN. PES pressures were measured on the tenth postoperative day with a four-channel catheter. RESULTS: Average PES pressures in patients with and without pharyngeal neurectomy were 12.82 +/- 6.11 mmHg and 17.40 +/-.72 mmHg respectively (p <.05). When compared with the critical point of 20 mmHg that is closely related to voice attainment in the group without pharyngeal neurectomy, 10 (40%) patients had pressure levels greater than 20 mmHg and in the other group only 1 (5%) patient had a pressure level greater than 20 mmHg. The difference between the groups with pressure levels greater than 20 mmHg was found to be statistically significant (p <.05). CONCLUSIONS: Pharyngeal neurectomy results in a statistically significant decrease of PES pressures in total laryngectomy patients.     

Comparison of topical iodine and silver sulfadiazine as therapies against sulfur mustard burns in a pig model

Sulfur mustard (SM) is a powerful vesicant used as an agent of chemical warfare. The severity of lesions incurred after exposure to SM reiterated the need for an efficient and rapid neutralizing agent against SM. Previous studies have shown that postexposure treatment with iodine is effective against SM lesions in rodents. In the current study we used the pig model to emulate SM-induced burn lesions, and observed the immediate effect of a single dose of iodine formulation treatment on these burns. SSD, a common agent recommended for use in both chemical and thermal burns was used as control. Results indicated that 1.27 mg of SM caused deep lesions and histopathological changes in the pig skin as scored in the biopsies obtained. A single application of an iodine formulation 20 minutes from exposure to SM exhibited no protective action on the skin as evident in the biopsies obtained 1, 3, 5, 10, and 21 days after treatment. SSD treatment induced the least protective action. The SSD-treated wounds also took the longest to heal. Attempts to neutralize the SM action with iodine compounds were not successful in the pig model. Currently, other compounds are being investigated. Attention must be drawn to the adverse effect of SSD on SM-induced wounds. Further studies must be initiated to elucidate this phenomenon.     

Clamshell切口和双侧后外侧切口开胸行双肺移植的临床效果比较

目的  探讨Clamshell切口和双侧后外侧切口序贯双肺移植术治疗终末期肺病的疗效差异。方法  回顾性分析接受双肺移植的120例受者的临床资料,按照手术方式不同分为双侧后外侧切口组（108例）和Clamshell切口组（12例）。收集并比较两组术中相关指标,包括手术时间、出血量、输血量、是否体外膜肺氧合（ECMO）支持、第一侧冷缺血时间、第二侧冷缺血时间,同时比较两组术后相关指标,包括住院时间、重症监护室（ICU）入住时间、气管插管时间、ECMO支持时间、用力肺活量（FVC）、第1秒用力呼气容积（FEV1）、吻合口狭窄发生率、支气管胸膜瘘发生率、围手术期病死率、术后第1次6 min步行距离。结果  Clamshell切口组出血量、输血量均多于双侧后外侧切口组（均为P < 0.05）,Clamshell切口组ECMO支持率和第二侧冷缺血时间低于或短于双侧后外侧切口组（均为P < 0.05）。Clamshell切口组气管插管时间及ECMO支持时间均短于双侧后外侧切口组（均为P < 0.05）。结论  Clamshell切口和双侧后外侧切口的手术方案应用于序贯双肺移植均安全有效,双侧后外侧切口在不明显增加手术时间的情况下,可显著减少受者的出血量和输血量。而与双侧后外侧切口比较,Clamshell切口供肺冷缺血时间、气管插管时间和ECMO支持时间显著缩短。     

Effect of variation in systemic blood flow on plasma TNF-alpha in a pig model with left ventricular assist device

Tumor necrosis factor-alpha (TNF-alpha) release has been implicated in a sepsis-like syndrome following cardiopulmonary bypass (CPB). This also may be important in patients who have had a left ventricular assist device (LVAD) implanted. This report investigates the effect of reducing systemic blood flow on hemodynamic response, mixed venous oxygen saturation (SvO(2)), and the release of TNF-alpha. LVADs were implanted in 9 pigs. The aorta was clamped, and thus the LVAD flow represented the entire systemic blood flow. Plasma TNF-alpha in the femoral artery (FA) and superior mesenteric vein (SMV) was measured at baseline and following systemic blood flow changes. Simultaneously, hemodynamic parameters and oxygen saturation in the pulmonary artery (SvO(2)) were measured. Following reductions in systemic blood flow, plasma TNF-alpha increased gradually to a maximum level at a systemic blood flow of 20%. There was no significant difference between TNF-alpha levels in the SMV and the FA. There was a significant (p < 0.05) correlation between cardiac index, stroke volume index, and TNF-alpha. The SvO(2) decreased significantly (p < 0.05) at a systemic blood flow of 30 and 20%. A rise in TNF-alpha occurred when the SvO(2) was less than 75%. The data demonstrate that a reduction in systemic blood flow causes an increase in plasma TNF-alpha. This can lead to the development of a sepsis-like syndrome in a group of patients who already are hemodynamically compromised. While weaning short-term LVAD support, rapid diminution of the cardiac output and the pump flow must be avoided.     

腹腔镜离断性肾盂成形术动物模型的建立方法

目的建立模拟训练腹腔镜离断性肾盂成形术的动物模型。方法选择体质量25kg左右的小型猪作为实验模型，速眠新（0．1ml／kg）和戊巴比妥钠（0．25g／kg）麻醉。经脐部导入CO2制备气腹，取侧卧位后，放置3个套管。分离肾脏和输尿管，斜形裁剪输尿管远切端。取肾门附近一段小肠与肾上极固定后，环形裁剪小肠壁约3cm，以此段小肠模拟扩张肾盂。按腹腔镜离断性肾盂成形术的标准方法进行肾盂输尿管吻合。术中顺行放置双J管于肾盂输尿管内。4名学员均有体外模拟训练经验，按照手术时间和肾盂输尿管吻合质量评估学员的学习曲线。结果该模型能够模拟完成腹腔镜离断性肾盂成形术的各项技术要求，而且每侧肾脏输尿管可以在相同解剖毗邻关系下进行3次肾盂成形术。在学员接受了12次肾盂成形术训练后，平均手术时间从最初的（140．0±20．3）min降为（63．0±7．1）min（P＜0．01）。学员均能熟练完成无张力的肾盂输尿管吻合。结论本模型的建立能够使学员掌握肾盂成形术的腔内操作技巧和手术方法。此外，本模型利用小肠替代扩张肾盂从而能够提供更多的训练机会。     

Comparison of monoscopic insertable, remotely controlled imaging device with a standard laparoscope in a porcine model

Laparoscopic imaging has remained relatively unchanged since the introduction of the rod-lens system. The intent here is to improve imaging by designing and building sensors and effectors placed directly into the body and controlled remotely. An 11-mm monoscopic insertable pan/tilt endoscopic imaging device with an integrated light source was studied. In vivo testing included simulated appendectomy, nephrectomy, suturing, and running the bowel in a porcine model (n = 6). Subjective impression and time for each procedure were compared using each imaging modality. The insertable imaging device seemed easier and more intuitive to use than a standard laparoscope. Time to perform procedures was better than or equivalent to a standard laparoscope. The insertable camera was subjectively preferred, and times for completion of complex tasks were shorter using the insertable camera. The insertable imaging device has the potential to be an integral part of surgical system platforms.     

Comparison of tendon-bone healing between a newly developed ultrasound device and the conventional metallic drill in a rabbit MCL reconstruction model

BackgroundLigament reconstructive surgeries demand tunnel creation using an over-drilling technique, though this technique has some problems such as metallic particle liberation or difficulties in tunnel creation other than circular cross-section. Recently, a new ultrasound (US) device for bone excavation to overcome these problems was developed. This study aimed to compare the tendon-bone healing in tunnels created using the new US device to that created using the conventional drill in a rabbit model.MethodsA total of 72 rabbits underwent a reconstruction for the anterior half of the medial collateral ligament (MCL) using a half of the patellar tendon. For the femoral tunnel creation, a new US device was used in 36 rabbits (US group), while a conventional metallic drill was used for the remaining 36 rabbits (DR group). At 4, 8, and 12 weeks postoperatively, biomechanical (n = 10) and histological (n = 2) evaluations were performed.ResultsThe ultimate failure load was almost equivalent between the US and DR groups at each period (US/DR; 4 weeks, 50.0 ± 12.8 N/43.4 ± 18.9 N, p = 0.62; 8 weeks, 78.6 ± 11.5 N/77.3 ± 29.9 N, p = 0.92; and 12 weeks: 98.9 ± 33.5 N/102.2 ± 38.3 N, p = 0.80). Pull-out failure from the femoral tunnel was only observed in two rabbits in the US group and one rabbit in the DR group at 4 weeks postoperatively. At 8 and 12 weeks, all specimens had a mid-substance tear. The collagen fiber continuity between tendon and bone occurred 8 weeks postoperatively in both groups and no histological difference was recognized throughout the evaluation period.ConclusionsThe tunnels created using the new US device and the conventional drill had equivalent biomechanical and histological features in tendon-bone healing. The bone excavation technology by the new US device may be applicable in ligament reconstructive surgeries.     

Comparison of invasive and less-invasive techniques of cardiac output measurement under different haemodynamic conditions in a pig model

BACKGROUND AND OBJECTIVE: Despite the introduction of various less-invasive concepts of cardiac output measurement, pulmonary arterial thermodilution is still the most common measurement technique. METHODS: This prospective controlled study was designed to compare different methods of cardiac output measurement simultaneously. Pulmonary arterial thermodilution, transpulmonary thermodilution (PiCCO), trans-oesophageal echo-Doppler probe (HemoSonic) and partial carbon dioxide rebreathing technique (NICO monitor) were evaluated against a peri-aortic transit-time flow-probe as reference method in a clinically relevant animal model. After approval from the Local Ethics Committee on Animal Research, the investigations were conducted in nine anesthetized domestic pigs. Systemic haemodynamics were modulated systematically by the application of catecholamines, caval occlusion and exsanguination. Statistical analysis was performed with Bland-Altman and linear regression. RESULTS: A total of 366 paired cardiac output measurements were carried out at a reference cardiac output between 0.5 and 7 L min(-1). The correlation coefficients for pulmonary arterial and transpulmonary thermodilution against reference were 0.93 and 0.95, for trans-oesophageal Doppler and partial rebreathing technique 0.84 and 0.77. Pulmonary arterial thermodilution and transpulmonary thermodilution showed comparable bias and limits of agreement. Where HemoSonic showed an overestimation of cardiac output at a higher precision, NICO overestimated low and underestimated higher cardiac output values. CONCLUSIONS: Our data suggest that pulmonary arterial thermodilution and PiCCO may be interchangeably used for cardiac output measurement even under acute haemodynamic changes. The method described by Bland and Altman demonstrated an overestimation of cardiac output for both thermodilution methods. HemoSonic and NICO offer non-invasive alternatives and complementary monitoring tools in numerous clinical situations. Trend monitoring and haemodynamic optimizing can be applied sufficiently, when absolute measures are judged critically in a clinical context. The use of the NICO system seems to be limited during acute circulatory changes.