Beyond prone position in percutaneous nephrolithotomy: a comprehensive review

Context

Percutaneous nephrolithotomy (PNL) is traditionally performed with the patient in the prone position.

Objective

To assess the efficacy and safety of the prone and supine positions, particularly in obese patients and in those with staghorn calculi.

Evidence acquisition

A Medline search was conducted for articles published during the last 10 yr related to PNL in the prone and supine positions.

Evidence synthesis

This search revealed 9 published studies for supine and 25 for prone PNL. None of the supine PNL studies reported visceral injuries, while transfusion rates were 0.0–9.4% and stone-free rates were 69.6–95.0%. One study of supine PNL evaluated a significant proportion of obese patients. Prone PNL studies in obese patients report transfusion rates of 3.2–8.8% and stone-free rates of 79.0–89.2%.In the only randomized study, excluding obese patients and staghorn calculi, operative time favors the supine position. A nonrandomized comparative study demonstrated similar complication rates with insignificant improvement in treatment success for supine PNL; however, when comparing series with similar proportions of staghorn calculi cases, there are slightly improved outcomes for prone PNL. Moreover, comparison of weighted means favors prone PNL.

Conclusions

For obese patients and staghorn calculi, prone PNL appears to be associated with decreased operative times with similar bleeding rates and slightly better stone-free rates than supine PNL.     

Kidney Access Device

Introduction:

Percutaneous nephrolithotomy is the most complicated stone surgery technique to learn. The steep learning curve is related mainly to obtaining precise renal access by puncturing the targeted calyx. A minimally misaligned puncture may lead to torrential bleeding, failure of the surgery, and complications. Renal puncture can take a long time, and the increased fluoroscopic time is a hazard for the patient and surgeon.

Methods:

To aid in renal puncture and overcome the learning curve associated with learning the renal puncture technique, we designed a kidney access device (KAD), which helps align the 3-dimensional targeted calyx under fluoroscopy for precise needle placement. The KAD allows access to calyces at all angles. A 3-step puncture technique was formulated for puncturing the kidney using the KAD in a porcine model (with comparable renal size and anatomy with humans). To evaluate the practicality of the KAD and its possible advantages and limitations, the KAD was used to puncture 3 targeted calyces of bilateral kidneys in 4 pigs. Guidewires were inserted into the renal collecting system through the placed needle.

Results:

Mean time per puncture was 4 ± 2 minutes (n = 24). Necropsy showed no retroperitoneal hematoma, visceral organ injury, or active bleeding from kidneys in any of the pigs. Kidneys were dissected and precise intrarenal placements of guidewires in relation to targeted calyces were noted at all 24 sites.

Conclusions:

The KAD with the 3-step technique aids in the safe and accurate renal puncture, even in novice hands, while drastically reducing operative and fluoroscopy time. The KAD may also be used to access other organs and has potential applications in minimally invasive surgery.     

Safety of percutaneous endoscopic gastrostomy after trauma laparotomy

Background

Trauma patients frequently require long-term enteral access because of injuries to the head, neck, or gastrointestinal tract. Noninvasive methods for gastrostomy placement include percutaneous endoscopic gastrostomy (PEG) and percutaneous radiographic gastrostomy (PRG). In patients with recent trauma laparotomy, PEG placement is felt to be relatively contraindicated because of the concerns about altered anatomy. We hypothesize that there is no increased rate of complications related to PEG placement in patients with trauma laparotomy compared with those without laparotomy provided that basic safety principles are followed.

Materials and methods

This retrospective study evaluates all percutaneous gastrostomies (both PEG and PRG) placed in trauma patients admitted at a level I trauma center between January 1, 2007 and March 30, 2010. The electronic medical records of the 354 patients were reviewed through 30 days after procedure, and patients were further subdivided by the history of laparotomy. Statistical analysis was performed using Fisher exact test or two-tailed t-test, as appropriate.

Results

In patients with no prior trauma laparotomy, successful PEG placement occurred in 92.2% of patients, the remainder underwent PRG placement. Of patients with prior trauma laparotomy, 82.4% had successful PEG placement. Two percent of attempted PEG placements failed in patients with no previous trauma laparotomy, whereas 11.8% failed in patients with recent trauma laparotomy. The overall complication rate was 2.0%, with no recorded complications in patients with trauma laparotomy before PEG placement.

Conclusions

These data suggest that surgeons should not consider recent trauma laparotomy a contraindication to PEG placement.     

Lovastatin prevents discography-associated degeneration and maintains the functional morphology of intervertebral discs

Background context

Discography is an important diagnostic approach to identify the painful discs. However, the benefit of discography, a procedure involving needle puncture and injection of the diagnostic agent into the intervertebral disc, is controversial and has been reported to be associated with accelerated degeneration.

Purpose

To investigate the effect of lovastatin on the prevention of degeneration caused by a discography simulation procedure in rat caudal discs.

Study design

In vivo study using rat caudal discs.

Methods

A single flexible 27-gauge needle puncture into rat caudal discs was performed under fluoroscopic monitoring. Different concentrations (0.1, 1, 5, and 10 μM) of lovastatin were prepared and injected into randomly chosen caudal discs. RNA expression of selected genes, histologic, and immunohistochemical staining were performed to evaluate the phenotypic effects of lovastatin on rat caudal discs.

Results

Simulation of the discography procedure by puncturing the rat caudal discs with a 27-gauge needle and injection of saline solution induced degenerative changes in the nucleus pulposus with minimal damage to the annulus fibrosus. Aggrecan, Type II collagen, and SOX9 expressions were upregulated, whereas Type I collagen expression was significantly suppressed in discs treated with 5 and 10 μM lovastatin. Discs treated with 5 and 10 μM lovastatin were subjected to alcian blue staining and immunohistochemistry that revealed higher levels of glycosaminoglycans and an increase in the number of cells producing S-100 proteins, Type II collagen, and bone morphogenetic protein-2 (BMP-2), respectively. The most effective phenotypic repair was observed in discs treated with 10 μM lovastatin.

Conclusions

Intradiscal administration of lovastatin solution upregulated the expressions of BMP-2 and SOX9 and promoted chondrogenesis of rat caudal discs after needle puncture and substance injection. Therefore, we suggest that lovastatin promotes disc repair and can be used as a potential therapeutic agent for biological repair of disc degeneration after the diagnostic discography procedure.     

Retroperitoneal and Transperitoneal Robot-Assisted Pyeloplasty in Adults: Techniques and Results

Background

The surgical management of ureteropelvic junction obstruction (UPJO) has dramatically evolved over the past 20 yr due to the development of new technology.

Objective

Our aim was to report the feasibility and efficacy of robot-assisted pyeloplasty (RAP) performed by either the retroperitoneal or the transperitoneal approach.

Design, setting, and participants

A stage 2 investigative study was conducted including development (stage 2a) and exploration (stage 2b) of transperitoneal and retroperitoneal RAP performed in 55 patients at an urban tertiary university department of urology.

Surgical procedure

Retroperitoneal RAP was performed with the patient in full flank position using a 12-mm Hasson-style optical port at the tip of the 12th rib, plus two operative 8-mm robotic trocars and an assistant 5-mm port. The stenotic ureteropelvic junction was excised, the ureter was spatulated, and a dismembered pyeloplasty was performed in all cases. Transperitoneal RAP was performed with the patients in the 60° flank position. The optical port is in the umbilical area, plus two 8-mm operative robotic ports and one 5-mm assistant port. The pyeloplasty technique is similar to the retroperitoneoscopic approach. In both groups, the stent can be positioned in an anterograde or retrograde fashion.

Measurements

Success consisted of no evidence of obstruction on computed tomography urography or mercaptoacetyltriglycine-3 diuretic renal scan, no postoperative symptoms, and no further treatment.

Results and limitations

Thirty-six patients underwent retroperitoneoscopic RAP and 19 transperitoneal RAP for UPJO. All the procedures were completed with robotic assistance. The overall objective success (measured by diuretic renal scan and/or imaging techniques) was 96% with two cases of recurrence (both in the retroperitoneal group). The main limitation was the short follow-up, although all patients reached at least a 6-mo follow-up.

Conclusions

RAP performed either retroperitoneally or transperitoneally was revealed as a feasible and reproducible surgical option for the treatment of UPJO, offering a subjective optimal plasty reconfiguration at short follow-up.     

The effect of needle size inducing degeneration in the rat caudal disc: evaluation using radiograph,magnetic resonance imaging,histology, and immunohistochemistry

Background context

The rat caudal disc has been increasingly used in studying of disc degeneration because of its simplicity, low cost, and efficiency. However, the reproducibility and standardization are essential to facilitate the investigations of biologic therapeutics at different stages of degeneration.

Purpose

To identify the effect of different needle gauges to the degenerative response in rat caudal discs and to examine its pathogenesis by looking at the cellular and matrix changes.

Study design

In vivo study of injury-induced rat caudal disc degeneration using needle puncture.

Patient sample

Thirty-six Lewis rats aged 12–14 weeks.

Outcome measures

The induced degenerative discs were analyzed by plain radiograph, magnetic resonance imaging (MRI) and histological examination. Proteoglycan content was assessed by alcian blue stain. Immunohistochemistry using aggrecan, collagen II, and Sox-9 was also evaluated to investigate cell differentiation and matrix changes.

Methods

All rats were divided into three groups according to different needle gauges (18G, 20G, and 22G). Caudal discs were punctured percutaneously under image guidance. Radiographs and MRI were obtained at 2 weeks interval until 8 weeks. At each time point, three rats from each group were sacrificed for histological analysis and immunohistochemistry.

Results

Larger needle gauges, especially 18G, produced more deterioration of the disc when compared with smaller sizes, particularly with time. Significant differences were identified in almost all parameters compared between 18G and 22G at the 8-week time point. For the effect of time in the same needle size, the differences occurred between 2- or 4-week and 8-week time point in the 18G and 20G groups. The proteoglycan and aggrecan stain gradually decreased over time. Chondrogenic differentiation was identified within the degenerative disc by detecting Sox-9 positive cells and collagen II accumulation increased as degeneration progressed.

Conclusions

The puncture-induced degenerative changes in rat caudal discs can imitate the human degenerative cascade as observed in plain radiograph, MRI, histology, and immunohistochemistry. We suggest that needle size affects the occurrence of progression of degeneration; thus, the large needle size was required to accelerate the deterioration. The size of needle and time point after injury should be considered when investigating the effect of therapeutic materials to retard degeneration or regenerate the intervertebral disc.     

Influence of Medial Collateral Ligament Release for Internal Rotation of Tibia in Posterior-Stabilized Total Knee Arthroplasty: A Cadaveric Study

Background

Previous studies suggested that changes in kinematics in total knee arthroplasty (TKA) affected satisfaction level. The aim of this cadaveric study was to evaluate the effect of medial collateral ligament (MCL) release by multiple needle puncture on knee rotational kinematics in posterior-stabilized TKA.

Evaluation of a training method for transtracheal punction for emergency oxygenation

Introduction

Transtracheal oxygenation is a lifesaving technique in a cannot-ventilate, cannot-intubate situation, in setting percutaneous transtracheal catheter.

Objective

To assess training for cricoid membrane puncture performed with a Ravussin needle.

Method

Ten residents in anaesthesiology nearing completion of their training participated in the study. Following a didactic session and a video demonstration, participants performed percutaneous transtracheal punctures on fresh cadavers. Success rate and time to perform the puncture were measured. Results are expressed as mean ± SD.

Results

By the third attempt, all procedures were successful. Mean performance time at the first attempt was 31.2 ± 21.8 s, progressively decreasing with the following attempts to reach a plateau by the third attempt (20.6 ± 19.3s). Performance time varies with the cadaver's morphology and the ability to recognize anatomic landmarks. However, whatever the difficulty, performance time is 40 s or less by the third attempt.

Conclusion

Percutaneous transtracheal catheter setting is a life saving technique with which every anaesthesiologist should be familiar. Viewing a pedagogic videotape and training on cadavers provides a rapid and effective training method for cricoid membrane puncture. Four attempts seem necessary to obtain an optimal success rate.     

Endoscopic Combined Intrarenal Surgery in Galdakao-Modified Supine Valdivia Position: A New Standard for Percutaneous Nephrolithotomy?

Background

Percutaneous nephrolithotomy (PCNL), the gold standard for the management of large and/or complex urolithiasis, is conventionally performed with the patient in the prone position, which has several drawbacks. Of the various changes in patient positioning proposed over the years, the Galdakao-modified supine Valdivia (GMSV) position seems the most beneficial. It allows simultaneous performance of PCNL and retrograde ureteroscopy (ECIRS, Endoscopic Combined Intra-Renal Surgery) and has unquestionable anaesthesiological advantages.

Objective

To prospectively analyse the safety and efficacy of endoscopic combined intrarenal surgery (ECIRS) in GMSV position for the treatment of large and/or complex urolithiasis.

Design, setting, and participants

From April 2004 to December 2007, 127 consecutive patients who were followed in our department for large and/or complex urolithiasis were selected for surgery (American Society of Anesthesiologists [ASA] score 1–3, no active urinary tract infection [UTI], any body mass index [BMI]).

Intervention

All the patients underwent ECIRS in GMSV position. Technical choices about percutaneous access, endoscopic instruments and accessories, and postoperative renal and ureteral drainage are detailed.

Measurements

Patients’ mean age plus or minus standard deviation (± SD) was 53.1 yr ± 14.2. Of the 127 patients, 5.5% had congenital renal abnormalities, 3.9% had solitary kidneys, and 60.6% were symptomatic for renal colics, haematuria, and recurrent UTI. Mean stone size ± SD was 23.8 mm ± 7.3 (range: 11–40); 33.8% of the calculi were calyceal, 33.1% were pelvic, 33.1% were multiple or staghorn, and 4.7% were also ureteral.

Results and limitations

Mean operative time ± SD was 70 min ± 28, including patient positioning. Stone-free rate was 81.9% after the first treatment and was 87.4% after a second early treatment using the same percutaneous access during the same hospital stay (mean ± SD: 5.1 d ± 2.9). We registered overall complications at 38.6% with no splanchnic injuries or deaths and no perioperative anaesthesiological problems.

Conclusions

ECIRS performed in GMSV position seems to be a safe, effective, and versatile procedure with a high one-step stone-free rate, unquestionable anaesthesiological advantages, and no additional procedure-related complications.     

Incidence of retrorenal colon during percutaneous nephrolithotomy

Objective

The aim of this study was to investigate retrorenal colon incidence in percutaneous nephrolithotomy (PNL) interventions made in our clinic.

Materials and Methods

Clinical data of 804 PNL patients, accumulated over a 7 year period (2006-2012), was surveyed. The patient files were reviewed retrospectively, and only those who had abdominal computed tomography (CT) images before PNL intervention were included in the study. In the CT images, the position of both the ascending and descending colon in relation to the right and left kidneys were evaluated.

Results

According to our hospital reports, 394 patients with CT images were included in the present study 27 patients (6.9%) had retrorenal colon, of which 18 (4.6%) were on the left side, 4 (1.0%) on the right side and 5 (1.3%) had bilateral retrorenal colons. Colonic perforation complication was seen only in two patients and the colonic perforation rate was 0.3%. These two cases had no CT images.

Conclusions

PNL, in the process of becoming the standard treatment modality, is a safe and reliable technique for renal stone treatment. Colonic injury should be taken into consideration during PNL interventions of the lower pole of the kidney (especially on the left side) due to the location of retrorenal colon.     

Rates and indications for surgical breast biopsies in a community-based health system

Background

High rates of surgical breast biopsies in community hospitals have been reported but may misrepresent actual practice.

Methods

Patient-level data from 5,757 women who underwent breast biopsies in a large integrated health system were evaluated to determine biopsy types, rates, indications, and diagnoses.

Results

Between 2008 and 2010, 6,047 breast biopsies were performed on 5,757 women. Surgical biopsy was the initial diagnostic procedure in 16% (n = 942) of women overall and in 6% (72 of 1,236) of women with newly diagnosed invasive breast cancer. Invasive breast cancer was diagnosed in 72 women (8%) undergoing surgical biopsy compared with 1,164 (24%) undergoing core needle biopsy (P < .001, age adjusted). Main indications for surgical biopsies included symptomatic abnormalities, technical challenges, and patient choice.

Conclusions

Surgical biopsy was the initial diagnostic procedure in 16% of women with breast abnormalities, comparable with rates at academic centers. Rates could be improved by more careful consideration of indications.     

Intrarenal Surgery vs Percutaneous Nephrolithotomy in the Management of Lower Pole Stones Greater than 2 cm

Purpose

To compare the efficacy of RIRS and PNL in lower pole stones ≥2 cm. Materials and and Methods: A total of 109 patients who underwent PNL or RIRS for solitary lower pole stone between April 2009 and December 2012, were retrospectively analyzed. Lower pole stone was diagnosed with CT scan. Stone size was assessed as the longest axis of the stone. All patients were informed about the advantages, disadvantages and probable complications of both PNL and RIRS before the selection of the procedure. Patients decided the surgery type by themselves without being under any influences and written informed consent was obtained from all patients prior to the surgery. Patients were divided into two groups according to the patients’ preference of surgery type. Group 1 consisted of 77 patients who underwent PNL and Group 2 consisted of 32 patients treated with RIRS. Stone free statuses, postoperative complications, operative time and hospitalization time were compared in both groups.

Results

There was no statistical significance between the two groups in mean age, stone size, stone laterality, mean follow-up periods and mean operative times. In PNL group, stone-free rate was 96.1% at first session and 100% after the additional procedure. In Group 2, stone-free rate was 90.6% at the first procedure and 100% after the additional procedure. The final stone-free rates and operative times were similar in both groups.

Conclusions

RIRS should be an effective treatment alternative to PNL in lower pole stones larger than 2 cm, especially in selected patients.     

Determination of the appropriate catheter length and place for needle thoracostomy by using computed tomography scans of pneumothorax patients

Introduction

The primary goal of this study was to compare the chest wall thicknesses (CWT) at the 2nd intercostal space (ICS) at the mid-clavicular line (MCL) and 5th ICS at the mid-axillary line (MAL) in a population of patients with a CT confirmed pneumothorax (PTX). This result will help physicians to determine the optimum needle thoracostomy (NT) puncture site in patients with a PTX.

Materials and methods

All trauma patients who presented consecutively to A&E over a 12-month period were included. Among all the trauma patients with a chest CT (4204 patients), 160 were included in the final analysis. CWTs were measured at both sides and were compared in all subgroup of patients.

Results

The average CWT for men on the 2nd ICS-MCL was 38 mm and for women was 52 mm; on the other hand, on the 5th ICS-MAL was 33 mm for men and 38 mm for women. On the 2nd ICS-MCL 17% of men and 48% of women; on the 5th ICS-MAL 13% of men and 33% of women would be inaccessible with a routine 5-cm catheter. Patients with trauma, subcutaneous emphysema and multiple rib fractures would have thicker CWT on the 2nd ICS-MCL. Patients with trauma, lung contusion, sternum fracture, subcutaneous emphysema and multiple rib fractures would have thicker CWT on the 5th ICS-MAL.

Conclusions

This study confirms that a 5.0-cm catheter would be unlikely to access the pleural space in at least 1/3 of female and 1/10 of male Turkish trauma patients, regardless of the puncture site. If NT is needed, the 5th ICS-MAL is a better option for a puncture site with thinner CWT.     

Training in percutaneous nephrolithotomy--a critical review

Aim

To study factors influencing training and maintaining skills in performing percutaneous nephrolithotomy (PCNL).

Methods

We matched key words, throughout Medline, MeSH, and Cochrane databases including: renal stone, percutaneous, nephrostomy, endourology, educational, training, learning curve, expertise, skill, residency, practice, survey, simulator, and robotics. For this topic we defined, if possible, levels of evidence based on International Consultation on Urological Diseases (ICUD) and World Health Organization recommendations.

Results

Obtaining renal access is one of the most important factors in training for PCNL. A resident has to perform about 24 PCNL procedures to obtain a good proficiency during the residence period. Competence at performing PCNL is reached after 60 cases and excellence is obtained at >100 cases. Stone centers providing all the endoscopic treatment options seem to provide the best conditions to ensure a sufficient volume of patients recruited. Virtual reality simulators may have a potential in training for PCNL. To maintain one's expertise, participation in continuing educational programs is recommended.

Conclusion

PCNL is currently the most complicated stone surgery technique to teach. The steep learning curve is mainly related to obtaining renal access. The traditional method of acquiring surgical skills is by apprenticeship in the absence of validated virtual simulators. Given the complexity of the treatment of renal stones, one may consider a centralized renal stone treatment in dedicated stone centers.     

Increasing the specimen adequacy of transpedicular vertebral body biopsies. Role of intraoperative scrape cytology

Background context

Obtaining adequate representative material has been a problem in transpedicular vertebral body biopsies resulting in inconclusive diagnosis and delayed management. By rapidly confirming the adequacy of the material intraoperatively, the rate of negative biopsies can be minimized. Present study evaluates the role of intraoperative cytology in increasing the diagnostic yield of vertebral biopsies.

Purpose

To evaluate the role of intraoperative cytological confirmation in increasing the specimen adequacy of vertebral biopsies.

Study design

A prospective cytological and histopathologic study.

Patient sample

Thirty-nine patients undergoing transpedicular biopsy were included.

Outcome measures

Adequacy and accuracy along with sensitivity and specificity of transpedicular biopsies with and without adopting scrape cytological screening were analyzed.

Methods

After obtaining transpedicular specimens, they were initially screened by intraoperative cytology before submitting for histopathologic examination. Cytological smears were prepared by rapid hematoxylin and eosin technique. Additional specimens were obtained if cytology showed inadequate or inconclusive cells.

Results

Of 39 patients who underwent transpedicular biopsy, the intraoperative cytology confirmed 32 (82.1%) specimens as adequate, 5 (12.8%) inadequate, and 2 (5.1%) as inconclusive. Adequacy of biopsy specimens with intraoperative cytology was found to have a sensitivity of 96.9%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 87.5%. If the intraoperative cytology was not adopted, six of 39 (15.4%) patients would have required repeat biopsy. Of the 47 specimens from 39 lesions, 46 intraoperative cytological diagnoses correlated well with the histopathology, with an accuracy of 95.7%. The average time taken to report the adequacy was 8.9±1.7 minutes.

Conclusions

Onsite intraoperative cytology is a rapid and an inexpensive technique to obtain accurate and adequate vertebral body tissue specimen with 100% diagnostic yield. The technique can be adopted easily into day-to-day practice and requires only few glass slides and regular reagents.     

Burden of complications from needle penetration of plastic ports in children

Background

Complications of totally implanted venous access ports are well documented. A concerning mechanical complication we have encountered is posterior penetration of plastic ports with the access needle. The purpose of this study is to investigate the burden of posterior penetrations.

Methods

We performed a retrospective review of all ports placed between November 2007 and December 2011 at a single institution.

Results

There were 247 children who received a port. 117 children (47%) received a port with a plastic posterior wall, 95 children (38%) received a port with a metal posterior wall, and 35 children (14%) had ports that were unable to be identified as plastic or metal. Posterior port penetrations occurred 8 times (3.2% overall, 6.8% of plastic ports). All perforations occurred in plastic ports of a single brand and product code. Average time from port insertion to penetration was 11.2 ± 21.3 months (range 0.3 to 63.4 months). Other complications included catheter malfunction (14), infection (9), pain (2), inability to draw/aspirate (4), leak (3), port migration (2), and malfunctioning not otherwise specified (15).

Conclusions

There is an unacceptably high risk of needle penetration of the posterior wall of plastic ports. We recommend utilizing ports with metal backing to avoid this complication.     

A novel biodegradable device for intestinal lengthening

Purpose

Previous studies demonstrated successful mechanical lengthening of rat jejunum using an encapsulated Nitinol spring device over a stabilizing guidewire. We sought to improve the applicability of intestinal lengthening by creating a biodegradable device.

Methods

Using properties of the Nitinol spring device, polycaprolactone (PCL) springs with similar outer diameter and spring constant were created. After in vitro testing in dry and hydrated environments, they were used to lengthen 1-cm isolated segments of rat jejunum in vivo. Retrieved segments were analyzed histologically.

Results

Optimal PCL spring devices had an average spring constant 1.8 ± 0.4 N/m, pitch 1.55 ± 0.85 mm, and band width 0.825 ± 0.016 mm. In vitro testing demonstrated stable spring constants. Jejunal segments were lengthened from 1.0 cm to 2.7 ± 0.4 cm without needing a stabilizing guidewire. Histology demonstrated increased smooth muscle thickness and fewer ganglia compared to controls. Lengthened jejunum was successfully restored into intestinal continuity and demonstrated peristalsis under fluoroscopy.

Conclusions

A novel biodegradable spring device was successfully created and used to mechanically lengthen intestinal segments. Use of a biodegradable device may obviate the need for retrieval after lengthening. This improves device applicability and may be useful for the treatment of short bowel syndrome.     

Minimal access extrapleural esophagoesophagostomy

Background/purpose

Minimal access repair of esophageal atresia is gaining acceptance but usually requires a transpleural approach. An extrapleural approach using a 2-cm incision has been described. The purpose of this study was to develop a less-invasive approach to extrapleural esophagoesophagostomy.

Methods

A 5-8 kg nonsurvivor piglet model was used to develop this technique. The extrapleural dissection was performed under direct vision utilizing transpleural thoracoscopy. A 16-gauge needle and a spatula were used to create an extrapleural space that allowed insertion of a 3-mm trocar. An 8F catheter with a 3-mL balloon was inserted through the trocar and inflated to create enough space to exchange it for a 5-mm trocar. A 12F catheter with a 5-mL balloon was inserted through the 5-mm trocar and inflated to enlarge the space. These steps were repeated at each of the 3 extrapleural port sites until one confluent extrapleural space was created that did not communicate with the transpleural port site. Esophagoesophagostomy was then completed within the extrapleural space.

Results

Thoracoscopic guidance and balloon dissection facilitated creation of an adequate extrapleural working space.

Conclusions

This new minimal access extrapleural approach offers an attractive alternative to the currently described minimal access approaches to esophagoesophagostomy.     

Average chest wall thickness at two anatomic locations in trauma patients

Background

Needle thoracostomy is the emergent treatment for tension pneumothorax. This procedure is commonly done using a 4.5 cm catheter, and the optimal site for chest wall puncture is controversial. We hypothesize that needle thoracostomy cannot be performed using this catheter length irrespective of the site chosen in either gender.

Methods

A retrospective review of all chest computed tomography (CT) scans obtained on trauma patients from January 1, 2011 to December 31, 2011 was performed. Patients aged 18 and 80 years were included and patients whose chest wall thickness exceeded the boundary of the images acquired were excluded. Chest wall thickness was measured at the 2nd intercostal (ICS), midclavicular line (MCL) and the 5th ICS, anterior axillary line (AAL). Injury severity score (ISS), chest wall thickness, and body mass index (BMI) were analyzed.

Results

201 patients were included, 54% male. Average (SD) BMI was 26 (7) kg/m². The average chest wall thickness in the overall cohort was 4.08 (1.4) cm at the 2nd ICS/MCL and 4.55 (1.7) cm at the 5th ICS/AAL. 29% of the overall cohort (27 male and 32 female) had a chest wall thickness greater than 4.5 cm at the 2nd ICS/MCL and 45% (54 male and 36 female) had a chest wall thickness greater than 4.5 cm at the 5th ICS/AAL. There was no significant interaction between gender and chest wall thickness at either site. BMI was positively associated with chest wall thickness at both the 2nd and 5th ICS/AAL.

Conclusion

A 4.5 cm catheter is inadequate for needle thoracostomy in most patients regardless of puncture site or gender.     

Initial Experimental Evaluation of Wireless Capsule Endoscopes in the Bladder: Implications for Capsule Cystoscopy

Background

Cystoscopy remains one of the most important diagnostic procedures for the lower urinary tract. Wireless capsule endoscopy was introduced in the 1990s but use to date is limited to gastroenterology.

Objective

We evaluated the feasibility in the pig model of using wireless capsule endoscopes (WCEs) for cystoscopy.

Design, setting, and participants

Experimental evaluation of capsule cystoscopy was performed in a 50-kg farm pig. The capsule was deployed into the bladder through a custom access sheath. Images were continuously transmitted at a rate of four frames per second to a laptop computer and processed using proprietary software. Manipulation of the WCE within the bladder was performed using a set protocol. The animal was then euthanized and gross inspection was performed.

Measurements

We measured the ability to deploy and manipulate the capsule within the bladder. Feasibility of capturing and retrieving images in real time was also assessed.

Results and limitations

The WCE was efficiently deployed and manipulated within the bladder passively and with the use of external magnets. The entire bladder mucosa was visualized. Real-time image transmission and capture were successful. No complications were seen during capsule cystoscopy. Minor urethral bleeding was observed after the experiment, likely related to placement of the access sheath required for deployment of the WCE. Limitations are that the evaluation of WCE was performed in the pig model, in only one female animal, using a nonsurvival approach. Furthermore, the study was not designed to differentiate normal from abnormal mucosal findings and focused solely on inspection of the bladder.

Conclusions

This report suggests that cystoscopy with a WCE is feasible. With this device, all aspects of the bladder mucosa could be visualized, and ongoing technologic and procedural developments are warranted for this new approach.