Cisterna chyli: A detailed anatomic investigation

The impact of lymphangiograpy on chyle leakage treatment duration after pancreatic surgery

PURPOSE

Chyle leakage (CL) is a common complication in pancreatic surgery. Lymphangiography is a therapeutic option for CL in cases of conservative treatment failure. This study investigated the effect of lymphangiography on the healing time of CL.

METHODS

We retrospectively evaluated 283 patients who underwent pancreatic resection between January 2016 and June 2022. The risk factors for CL and the treatment period were evaluated according to whether or not lymphangiography was performed.

RESULTS

Of the 29 patients (10.2%) that had CL, lymphangiography was performed in 6. Malignant disease, the number of harvested lymph nodes, and drain fluid volume on postoperative day 2 were identified as independent risk factors for CL. Lymphangiography was associated with the cumulative healing rate of CL, and patients who underwent lymphangiography had a significantly shorter treatment period. No lymphangiography-related adverse events were observed.

CONCLUSION

Lymphangiography is a feasible and safe treatment option for CL. The CL treatment period after pancreatic surgery was significantly shorter in patients who underwent lymphangiography than in those who did not. Our results suggest that lymphangiography may contribute to early improvement of persistent CL.

An Elemental Diet Reduces Chylous Ascites of Patients Undergoing Pancreatoduodenectomy in the Setting of Early Enteral Feeding

OBJECTIVES

The elemental diet (ED) is a formula to support nutritional status without increasing chylous burden. This study evaluates the efficacy of early ED feeding after pancreatoduodenectomy (PD).

MATERIALS AND METHODS

A prospective phase II study of consecutive patients who underwent PD with early ED feeding was conducted. Patient backgrounds, surgical outcomes, and ED feeding tolerability were compared with a historical cohort of 74 PD patients with early enteral feeding of a low residue diet (LRD).

RESULTS

The ED group comprised 104 patients. No patient in the ED group discontinued enteral feeding because of chylous ascites (CAs), whereas 17.6% of the LRD group experienced refractory CAs that disrupted further enteral feeding. The CAs rate was significantly decreased in the ED group compared with the LRD group (3.9% and 48.7%, respectively; P < 0.001). There was no significant difference in the incidence of major complications (ED: 17.3%, LRD: 18.9%; P = 0.844). Postoperative prognostic nutritional index was similar between the 2 groups ( P = 0.764). In multivariate analysis, enteral feeding formula, and sex were independent risk factors for CAs (LRD: P < 0.001, odds ratio, 22.87; female: P = 0.019, odds ratio, 2.78).

CONCLUSIONS

An ED reduces postoperative CAs of patients undergoing PD in the setting of early enteral feeding.

Back to the Future II-A Comprehensive Update on the Rapidly Evolving Field of Lymphatic Imaging and Interventions

ABSTRACT

Lymphatic imaging and interventional therapies of disorders affecting the lymphatic vascular system have evolved rapidly in recent years. Although x-ray lymphangiography had been all but replaced by the advent of cross-sectional imaging and the scientific focus shifted to lymph node imaging (eg, for detection of metastatic disease), interest in lymph vessel imaging was rekindled by the introduction of lymphatic interventional treatments in the late 1990s. Although x-ray lymphangiography is still the mainstay imaging technique to guide interventional procedures, several other, often less invasive, techniques have been developed more recently to evaluate the lymphatic vascular system and associated pathologies. Especially the introduction of magnetic resonance, and even more recently computed tomography, lymphangiography with water-soluble iodinated contrast agent has furthered our understanding of complex pathophysiological backgrounds of lymphatic diseases. This has led to an improvement of treatment approaches, especially of nontraumatic disorders caused by lymphatic flow abnormalities including plastic bronchitis, protein-losing enteropathy, and nontraumatic chylolymphatic leakages. The therapeutic armamentarium has also constantly grown and diversified in recent years with the introduction of more complex catheter-based and interstitial embolization techniques, lymph vessel stenting, lymphovenous anastomoses, as well as (targeted) medical treatment options. The aim of this article is to review the relevant spectrum of lymphatic disorders with currently available radiological imaging and interventional techniques, as well as the application of these methods in specific, individual clinical situations.

The application of a medium-chain fatty diet and enteral nutrition in post-operative chylous leakage: analysis of 63 patients

Background

Post-operative chylous leakage (CL) is the pathologic leakage of chylomicron fluid after surgery. This retrospective study was performed to evaluate a uniform oral nutrition management strategy on the post-operative CL.

Methods

We retrospectively reviewed patients who developed post-operative CL and received consultation from a clinical nutritionist in seven departments of the Second Affiliated Hospital of Dalian Medical University from May 2020 to April 2022. We designed the oral nutrition intervention program which mainly standardized the type and amount of foods contained in the medium-chain triglyceride (MCT) diet. The influencing factors of curative efficacy were analyzed. Finally, binary logistic regression analysis was conducted to observe the relationship between curative efficacy and potentially predictive variables, including post-operative albumin, post-operative hemoglobin, surgical procedure, and drainage volume at consultation.

Results

Sixty-three patients with post-operative CL were included in this analysis. Of this number, 58 patients were cured successfully without other treatments. Three patients had a significantly prolonged recovery period, and the remaining two cases were treated by reoperation therapy. The leakage volume at the initiation of enteral intervention had no statistically significant difference in seven surgical departments and surgical sites (left, right, median, and bilateral). The length of stay (LOS) of patients with CL after the intervention was not significantly increased in cardiac, hepatobiliary, gastrointestinal, and urological surgeries. Patients with CL had longer LOS than those without CL in gynecology (P=0.044) and thyroid surgery departments (P=0.008). Each unit increase in post-operative hemoglobin would increase the probability of an effective outcome by 8%, which was statistically significant (P = 0.037).

Conclusion

In treating patients with post-operative CL, we recommend the MCT diet and EN as the first option, rather than fasting, parenteral nutrition (PN), or octreotide.

Chyle Leak After Pancreatoduodenectomy: Clinical Impact and Risk Factors in a Nationwide Analysis

OBJECTIVE

The aim of this study was to assess the clinical impact and risk factors of chyle leak (CL).

BACKGROUND

In 2017, the International Study Group for Pancreatic Surgery (ISGPS) published the consensus definition of CL. Multicenter series validating this definition are lacking and previous studies investigating risk factors have used different definitions and showed heterogeneous results.

METHODS

This observational cohort study included all consecutive patients after pancreatoduodenectomy in all 19 centers in the mandatory nationwide Dutch Pancreatic Cancer Audit (2017-2019). The primary endpoint was CL (ISGPS grade B/C). Multivariable logistic regression analyses were performed.

RESULTS

Overall, 2159 patients after pancreatoduodenectomy were included. The rate of CL was 7.0% (n=152), including 6.9% (n=150) grade B and 0.1% (n=2) grade C. CL was independently associated with a prolonged hospital stay [odds ratio (OR)=2.84, 95% confidence interval (CI): 1.85-4.36, P <0.001] but not with mortality (OR=0.3, 95% CI: 0.0-2.3, P =0.244). In multivariable analyses, independent predictors for CL were vascular resection (OR=2.1, 95% CI: 1.4-3.2, P <0.001) and open surgery (OR=3.5, 95% CI: 1.7-7.2, P =0.001). The number of resected lymph nodes and aortocaval lymph node sampling were not identified as predictors in multivariable analysis.

CONCLUSIONS

In this nationwide analysis, the rate of ISGPS grade B/C CL after pancreatoduodenectomy was 7.0%. Although CL is associated with a prolonged hospital stay, the clinical impact is relatively minor in the vast majority (>98%) of patients. Vascular resection and open surgery are predictors of CL.

Renal cell carcinoma with tumor thrombus: A review of relevant anatomy and surgical techniques for the general urologist

Renal cell carcinoma (RCC) is estimated to account for 4.1% of all new cancer diagnoses and 2.4% of all cancer deaths in 2020 according to the National Cancer Institute SEER database. This will likely total 73,000 new cases and 15,000 deaths. RCC is one of the most lethal of the common cancers urologists will encounter with a 5-year relative survival of 75.2%. Renal cell carcinoma is one of a small subset of malignancies that are associated with tumor thrombus formation, which is tumor extension into a blood vessel. An estimated 4% to 10% of patients with RCC will have some degree of tumor thrombus extending into the renal vein or inferior vena cava at the time of diagnosis. Tumor thrombi change the staging of RCC and therefore are an important part of initial patient workup. It is known that such tumors are more aggressive with higher Fuhrman grades, N+ or M+ at time of surgery and have higher probability of recurrence with lower cancer-specific survival. Aggressive surgical intervention with radical nephrectomy and thrombectomy can be performed with survival benefits. Classifying the level of the tumor thrombus becomes vitally important in surgical planning as it will dictate the surgical approach. Level 0 thrombi may be amenable to simple renal vein ligation while level 4 can require thoracotomy and possible open-heart surgery with coordination of many surgical teams. Here we will review the anatomy associated with each level of tumor thrombus and attempt to construct an outline for surgical techniques that may be used. We aim to give a concise overview so that general urologists may use it to understand these potentially complicated cases.

The cisterna chyli: a systematic review of definition, prevalence, and anatomy

The cisterna chyli is a lymphatic structure found at the caudal end of the thoracic duct that receives lymph draining from the abdominal and pelvic viscera and lower limbs. In addition to being an important landmark in retroperitoneal surgery, it is the key gateway for interventional radiology procedures targeting the thoracic duct. A detailed understanding of its anatomy is required to facilitate more accurate intervention, but an exhaustive summary is lacking. A systematic review was conducted, and 49 published human studies met the inclusion criteria. Studies included both healthy volunteers and patients and were not restricted by language or date. The detectability of the cisterna chyli is highly variable, ranging from 1.7 to 98%, depending on the study method and criteria used. Its anatomy is variable in terms of location (vertebral level of T10 to L3), size (ranging 2-32 mm in maximum diameter and 13-80 mm in maximum length), morphology, and tributaries. The size of the cisterna chyli increases in some disease states, though its utility as a marker of disease is uncertain. The anatomy of the cisterna chyli is highly variable, and it appears to increase in size in some disease states. The lack of well-defined criteria for the structure and the wide variation in reported detection rates prevent accurate estimation of its natural prevalence in humans.

Visible Lymph Affluents in the D3 Volume: An MDCTA Pictorial Essay

BACKGROUND

There seems to be a gap in knowledge of the anatomy of mesenteric lymphatics between the superior mesenteric nodes and the intestinal trunk. To our knowledge, these central lymph vessels were not hitherto systematically searched for, described, or morphometrically analyzed. Our aim was to identify those vessels on the routine multidetector computerized tomography angiography (MDCTA), performed prior to right colectomy for cancer, with extended mesenterectomy, central vascular ligation, and D3 lymphadenectomy.

METHODS

A total of 420 MDCTA datasets were analyzed utilizing manual segmentation and 3D reconstruction, with the aid of image processing software Osirix, Mimics, and 3-matic. The 3D models and masks underwent a detailed topographic and morphometric analysis.

RESULTS

Significant vascular-like structures, having neither origin nor termination on the blood vessels, were noted in 18 cases (4.3%) in the D3 volume. The dimensions of visible lymph vessels varied, their mean diameter was 1.81 ± 0.61 mm, and the mean length was 38.07 ± 22.19 mm. In the vast majority of cases, the lymph vessels were situated in front of the superior mesenteric artery (SMA), coursing either longitudinally cranially (13 cases) or transversely/obliquely to the left (5 cases). In all cases but one, the lymph vessel passed at the left-hand side of the middle colic artery. As for the course shape, in seven cases, the lymph vessel appeared highly serpiginous.

CONCLUSIONS

The regular MDCTA can provide valuable information on mesenteric lymphatics and aid in surgical planning.

Interventional Management of Acquired Lymphatic Disorders

The lymphatic system is a complex network of tissues, vessels, and channels found throughout the body that assists in fluid balance and immunologic function. When the lymphatic system is disrupted related to idiopathic, iatrogenic, or traumatic disorders, lymphatic leaks can result in substantial morbidity and/or mortality. The diagnosis and management of these leaks is challenging. Modern advances in lymphatic imaging and interventional techniques have made radiology critical in the multidisciplinary management of these disorders. The authors provide a review of conventional and clinically relevant variant lymphatic anatomy and recent advances in diagnostic techniques such as MR lymphangiography. A detailed summary of technical factors related to percutaneous lymphangiography and lymphatic intervention is presented, including transpedal and transnodal lymphangiography. Traditional transabdominal access and retrograde access to the central lymph nodes and thoracic duct embolization techniques are outlined. Newer techniques including transhepatic lymphangiography and thoracic duct stent placement are also detailed. For both diagnostic and interventional radiologists, an understanding of lymphatic anatomy and modern diagnostic and interventional techniques is vital to the appropriate treatment of patients with acquired lymphatic disorders. ^©RSNA, 2022.

State-of-the-art imaging for lymphatic evaluation in children

The lymphatic system has been poorly understood and its importance neglected for decades. Growing understanding of lymphatic flow pathophysiology through peripheral and central lymphatic flow imaging has improved diagnosis and treatment options in children with lymphatic diseases. Flow dynamics can now be visualized by different means including dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL), the current standard technique to depict central lymphatics. Novel imaging modalities including intranodal, intrahepatic and intramesenteric DCMRL are quickly evolving and have shown important advances in the understanding and guidance of interventional procedures in children with intestinal lymphatic leaks. Lymphatic imaging is gaining importance in the radiologic and clinical fields and new techniques are emerging to overcome its limitations.

Systematic review of the incidence and risk factors for chyle leak after pancreatic surgery

BACKGROUND

The incidence of and risk factors for chyle leak, as defined by the 2017 International Study Group on Pancreatic Surgery, remain unknown.

METHODS

MEDLINE, EMBASE, and Scopus were systematically searched for studies of patients undergoing pancreatectomy that reported chyle leak according to the 2017 International Study Group on Pancreatic Surgery definition. The primary outcomes were the incidence of overall and clinically relevant chyle leak. A random-effects pairwise meta-analysis was used to calculate the incidence of chyle leak.

RESULTS

Thirty-five studies including 7,083 patients were included in the meta-analysis. The weighted incidence of overall chyle leak was 6.8% (95% confidence interval 5.6-8.2), and clinically relevant chyle leak was 5.5% (95% confidence interval 3.8-7.7). Pancreaticoduodenectomy, total pancreatectomy, and distal pancreatectomy were associated with a CL incidence of 7.3%, 4.3%, and 5.8%, respectively. Fourteen individual risk factors for chyle leak were identified from included studies. Younger age, low prognostic nutritional index, para-aortic node manipulation, lymphatic involvement, and post-pancreatectomy pancreatitis were significantly associated with chyle leak, all from individual studies.

CONCLUSION

The incidence of overall chyle leak and clinically relevant chyle leak after pancreatic surgery, as defined by the 2017 International Study Group on Pancreatic Surgery, is 6.8% and 5.5%, respectively. Several risk factors for chyle leak were identified in the present review; however, larger high-quality studies are needed to more accurately define these risks.

An unusual complication of tumor surgery: chylous leakage

PURPOSE

This study was designed to evaluate the effectiveness of conservative treatment for chylous leak after tumor surgery and to propose a management algorithm.

METHODS

The data of patients with postoperative chylous leak after tumor surgery in our institution between 2010 and 2019 were retrospectively reviewed. In this study, 469 laparotomies, 89 thoracotomies, and 57 cervical excisions were performed for tumor surgery in our institution.

RESULTS

Twelve patients with a median age of 4 (IQR, 3-8) years had postoperative chylous leak. All patients received total parenteral nutrition for a median of 13 days. Five patients had intravenous somatostatin for a median of 14 days (IQR, 9-16) to decrease chyle production. Eventually, chylous leak ceased in all patients with conservative treatment and surgical drains were removed after no leak was observed with enteral feeding.

CONCLUSIONS

The incidence of chylous leak in childhood tumor surgery is approximately 2%. Extended tumor resection and lymph node dissection lead to the injury of the delicate structures that drain chyle. Conservative treatment with total parenteral nutrition and somatostatin seems to be effective. In particular, somatostatin may be used in resistant cases. Conservative treatment can take up to 1 month. The algorithm consists of how to manage postoperative chylous leak in childhood.

Daily Triglyceride Output Volume as an Early Predictor for Chyle Leak Following Pancreaticoduodenectomy

BACKGROUND/AIM

Useful prophylaxes of chyle leak (CL) after pancreatic surgery have not been established. The aim of the study was to identify an early clinical predictor for CL.

PATIENTS AND METHODS

Fifty-five patients who underwent subtotal stomach preserved pancreaticoduodenectomy (SSPPD) were included. Clinical factors associated with postoperative CL were evaluated.

RESULTS

Eleven patients (20%) developed a CL after SSPPD. Shorter operative time, absent pancreatic fistula, and triglyceride output volume at postoperative day (POD) two were independent risk factors for CL. The receiver operating characteristics curve of the daily triglyceride output volume at POD two indicated a cut-off point of 177 mg (AUC=0.782; p=0.004; 95% CI=0.639-0.925). CL was significantly associated with prolonged postoperative hospital stay in patients who did not develop a pancreatic fistula (p=0.003).

CONCLUSION

Daily triglyceride output volume of >177 mg at POD two may be a predictor of CL following pancreaticoduodenectomy.

Anatomical study of the thoracic duct and its clinical implications in thoracic and pediatric surgery, a 70 cases cadaveric study

INTRODUCTION

Given the high variability and fragility of the thoracic duct, good knowledge of its anatomy is essential for its repair or to prevent iatrogenic postoperative chylothorax. The objective of this study was to define a site where the thoracic duct is consistently found for its ligation. The second objective was to define an anatomically safe surgical pathway to prevent iatrogenic chylothorax in surgery for aortic arch anomalies with vascular ring, through better knowledge of the anatomical relationships of the thoracic duct.

METHODS

Seventy adult formalin-fixed cadavers were dissected. The anatomical relationships of the thoracic duct were reported at the postero-inferior mediastinum, at levels T3 and T4.

RESULTS

The thoracic duct was consistently situated between the left anterolateral border of the azygos vein and the right border of the aorta between levels T9 and T10, whether it was simple, double, or plexiform. It was located medially, anteromedially, or posteriorly to the left subclavian artery in 51%, 21%, and 28% of the cases, respectively, at the level of T3. At T4, it was posteromedial in 27% of the cases or had no direct relationship with the aortic arch.

CONCLUSION

These results favor mass ligation of the thoracic duct at levels T9-T10 between the right border of the aorta and the azygos vein, eventually including the latter. To prevent iatrogenic postoperative chylothorax in aortic arch anomalies with vascular ring surgery, we recommend remaining strictly lateral to the left subclavian artery at the level of T3 to reach the aortic arch anomalies with vascular ring at T4.

Lymphovenous shunts: from development to clinical applications

The lymphatic system is a vast network of vessels that functions to return excess fluid from the interstitial space to the blood stream. Lymphovenous shunts are anastomoses, either natural or surgical, that connect the lymphatic and venous systems. Connections between the thoracic duct and venous system or between the right lymphatic duct and venous system are prime examples of anatomic lymphovenous shunts. Lymphovenous shunts are also present peripherally in tissues such as lymph nodes. Furthermore, pathologic lymphovenous shunts are observed in conditions such as lymphedema, malignancy, and lymphovenous malformations. Surgically, lymphovenous shunts may be constructed as an approach to treat lymphedema. Here, we discuss anatomic and surgical lymphovenous shunts in the context of normal development and disease. This perspective is intended to give an understanding of the role of lymphovenous shunts in health and disease and to show how they can be leveraged to treat disease surgically.

Abdominal lymphatic system visibility, morphology, and abnormalities in children as seen on routine MCRP and its association with immune-mediated diseases

PURPOSE

(1) To assess the visibility and diameters of the thoracic duct (TD) and cisterna chyli (CC) on MR cholangiopancreatography (MRCP) in children. (2) To evaluate for the presence of any lymphatic abnormalities and assess their association with diseases in which the immune system is implicated in etiopathogenesis.

METHODS

This retrospective study included 142 MRCPs performed in children 8-17 years old and without prior surgeries. Two radiologists reviewed all exams for visibility and diameters of the TD and CC, and presence of abnormal lymphatic collaterals. TD and CC diameters in various disease processes were compared using Student's t tests. The association of collaterals with immune-mediated diseases was assessed using Fisher's exact tests.

RESULTS

The TD and CC were seen in 134/142 (93.7%) cases with mean diameter of 3.25 ± 1.07 mm and 126/142 (88.7%) cases with mean diameter of 4.55 ± 1.37 mm respectively. The mean diameter of CC was larger in patients with portal hypertension (p = 0.021). There were no significant differences in the TD and CC diameters between immune-mediated and non-immune-mediated diseases. Retroperitoneal collaterals were seen in 41/142 (28.8%) of cases and were associated with both portal hypertension (p = 0.0019) and immune-mediated diseases (p = 0.0083).

CONCLUSION

The TD and CC can be visualized in the majority of children on routine MRCP images, and CC has larger diameter in patients with portal hypertension. The association of collaterals with immune-mediated diseases supports a potential role of the lymphatic system in the etiopathogenesis of immune-mediated diseases.

KEY POINTS

• The lymphatic system has been increasingly implicated in a number of inflammatory and immune-mediated diseases. • The abdominal lymphatic system can be visualized in the majority of children above 8 years on routine MRCP images. Similar to adult studies, the cisterna chyli is significantly larger in children with portal hypertension. • Retroperitoneal lymphatic collaterals, seen in 29% children, are associated with immune-mediated diseases, which supports the potential role of the lymphatic system in the pathogenesis of immune-mediated diseases.

Simultaneous Ipsilateral Vascularized Lymph Node Transplantation and Contralateral Lymphovenous Anastomosis in Bilateral Extremity Lymphedema with Different Severities

Background

Extremity lymphedema can occur bilaterally with different severities on each side. The aim of this study is to investigate the treatment outcomes of such patients with bilateral extremity lymphedema of different severities.

Patients and Methods

Between 2013 and 2017, patients with bilateral extremity lymphedema of different severities according to the Taiwan Lymphoscintigraphy Staging (TLS) system were retrospectively reviewed. Ipsilateral vascularized lymph node transplantation (VLNT) was indicated in TLS total obstruction and contralateral lymphovenous anastomosis (LVA) in TLS partial obstruction with patent lymphatic vessels on indocyanine green lymphography. Outcomes were assessed using circumference improvement, frequency of cellulitis, and lymphedema-specific quality of life (LYMQoL) questionnaires.

Results

A total of 10 patients with bilateral extremity lymphedema with median age of 63 (range 12–75) years were included. The median symptom duration of the lymphedematous limb was 60 (range 36–168) months and 12 (range 1–60) months in the VLNT and LVA group, respectively (p < 0.05). At average follow-up of 37.5 (range 14–58) months, the average limb circumference improvement was 2.4 (range − 3.3 to 7.8) cm in the VLNT group and 2.3 (range 0.3–7) cm in the LVA group (p = 1). The median episodes of cellulitis decreased significantly from 4 to 0.5 and 1 to 0 times/year in the VLNT and LVA group, respectively (p = 0.02, p = 0.06). The overall LYMQoL score improved from 4.5 preoperatively to 7.5 postoperatively (p < 0.01).

Conclusions

Limb-specific VLNT and LVA selected by TLS effectively treated bilateral extremity lymphedema with different severities.

Intranodal lymphangiography for chyle leakage after esophagectomy: A case report

Postoperative chylothorax after esophagectomy is a relatively rare complication, but treatment can sometimes be complicated. We report 3 cases of Lipiodol lymphangiography via inguinal lymph node puncture that was effective for chyle leakage occurring after esophagectomy. Case 1: A 67-year-old man with stage IIIA esophageal squamous cell carcinoma underwent radical esophagectomy by video-assisted thoracic surgery (VATS) following neoadjuvant chemotherapy (NAC). After enteral feeding, right pleural effusion drainage increased sharply and changed to white color that was diagnosed as chylothorax. Conservative treatment was started on postoperative day (POD) 15. On POD 50, intranodal Lipiodol lymphangiography and thoracic duct ligation were performed, resulting in complete improvement by the next day. Case 2: A 69-year-old man with stage IIIC esophageal cancer was treated salvage operation following chemoradiation. Postoperative chylothorax was diagnosed on POD 6. Despite conservative treatment, the pleural fluid volume did not decrease. Intranodal Lipiodol lymphangiography performed on POD 13 showed contrast medium draining from the thoracic duct near the tracheal bifurcation. Thoracotomy for thoracic duct ligation was performed on POD 15. Thereafter, drainage from the thoracic drain decreased significantly, and the right thoracic drain was removed 4 days later. Case 3: A 65-year-old man with Stage IVA hypopharyngeal cancer and Stage IIIA esophageal cancer underwent total pharyngopharyngeal esophagectomy by VATS following NAC. Postoperative chylothorax was diagnosed on POD 7. Despite conservative treatment, the pleural fluid volume did not decrease. Intranodal Lipiodol lymphangiography performed on POD 19 completely visualized the thoracic duct and showed no outflow of contrast from the main thoracic duct into the mediastinum. Pleural fluid decreased remarkably after lymphangiography. Intranodal Lipiodol lymphangiography for postoperative chylothorax accurately visualizes flow within the thoracic duct and clearly depicts its positional relationship with other organs. Besides lymphangiography is not only helps to determine the site of chyle leakage but can also be effective for curing chylothorax by less invasive and safer method.

Chyle leakage after robotic and open pancreaticoduodenectomy

BACKGROUND

Chyle leakage is a well-known but poorly characterized complication after pancreaticoduodenectomy (PD). No study examined the chyle leakage after robotic PD (RPD).

METHODS

Data regarding chyle leakage were prospectively collected and analyzed from patients undergoing RPD or open PD (OPD).

RESULTS

The study included 118 RPD and 165 OPD. Overall chyle leakage rate was 12.0%, with 13.6% for RPD and 10.9% for OPD. Chyle leakage was eventually resolved in all patients through conservative treatment. The drainage volumes were significantly higher in chyle leakage group from postoperative days (PODs) 1-7, with a median of 240 mL on POD 1 and POD 7, as compared to 160 mL on POD 1 and 70 mL on POD 7 for those without chyle leakage. The number of lymph nodes involved and resected and pancreatic head adenocarcinoma affected the risk of developing chyle leakage, whereas the surgical approach used (RPD or OPD) did not.

CONCLUSIONS

Chyle leakage after PD is not rare, and it can eventually be resolved through conservative treatment. The extent and radicality of the surgery probably have a significant effect on the risk of developing chyle leakage, but the surgical approach used does not.

Cisterna chyli: An important landmark in laparoscopic paraaortic lymphadenectomy

OBJECTIVE

Cisterna chyli is a pearl-shaped elongated lymphatic structure located at the level of L1-L2 vertebra just beneath the aorta (Hsu and Itkin, 2016 [1]). It receives lymphatic drainage of intestines and lower body structures (Loukas et al., 2007 [2]). Size, shape and location are all highly variable and in some autopsy series CC was identified in only half of the cases (Song, 2016 [3]). During the laparoscopic paraaortic lymphadenectomy inadvertent injury to otherwise unidentified CC could lead to refractory chylous ascites (Favero et al., 2010 [4]). The objective of this video is to demonstrate the anatomic localization and consequences of inadvertent injury to CC in laparoscopic paraaortic lymphadenectomy.

METHODS

Two different patients undergoing laparoscopic paraaortic lymphadenectomy were presented.

RESULTS

The first case is a 51 year old woman with grade III endometrioid adenocarcinoma of uterus who was subjected to laparoscopic staging (laparoscopic hysterectomy + BSO + pelvic and paraaortic lymphadenectomy). Intraoperatively an injury to cisterna chyli occurred which was sealed and repaired immediately. The second case is a woman with stage IIB clear cell cervical cancer undergoing laparoscopic staging (pelvic and paraaortic lymphadenectomy). In this case cisterna chyli could be recognized and preserved.

CONCLUSION

Cisterna chyli is an important anatomic structure which should be identified and preserved during laparoscopic paraaortic lymphadenectomy. Any iatrogenic injury to cisterna chyli could lead to chylous ascites and indeed in minority of these cases surgical intervention is required.

Anatomical variations in distal portion of the thoracic duct-A systematic review

The objective of this study was to identify and analyze the anatomical variations in the termination of the thoracic duct (TD) in cadavers or patients by anatomical dissections and surgical or radiological procedures for better knowledge of the interindividual variations through a systematic review. The search strategy included PubMed and reference tracking. Studies were identified by searching the electronic Medline databases. The search terms included "TD," "Jugular Vein," "Subclavian Vein," or "Cervical," and the protocol used is reported herein. These search results yielded 20 qualitative review articles out of the 275 articles consulted. We collected all the important data from these 20 articles with 1,352 TD analyzed by varying sources in our search. Regarding the characteristics of the studies and the anatomy of the TD, the results were heterogeneous. The TD most commonly terminates in the internal jugular vein in 54.05% of cases (95% confidence interval [CI]: 54.03; 54.07), in the jugular-venous angle in 25.79% (95% CI: 25.77; 25.81), and in the subclavian vein in 8.16% of cases (95% CI: 8.14;8.18). Other terminations were found in 12% of cases. This systematic review provided an overview of the variations in the distal portion of the TD. This study can be helpful for surgeons in selecting the most appropriate methods to achieve successful surgical results and avoid complications, such as chylothorax; it also offers detailed information on the cervical termination of the TD in new diagnostic and therapeutic methods involving the TD. Clin. Anat. 32:99-107, 2019. © 2019 Wiley Periodicals, Inc.

A radio-anatomical correlation study of the cisterna chyli

Surgical laparoscopic procedures in the retroperitoneal and supramesocolic spaces are increasingly frequent. There is a high risk of iatrogenic intraoperative injury of the retroperitoneal lymphatic structures during these procedures. A precise understanding of the anatomy of the thoracic duct (TD) and the cisterna chyli (CC) is essential for safe surgical procedures in this area. However, routine imaging procedures rarely and often incorrectly visualize the CC. The objective of this study was to evaluate the feasibility of a retrograde injection of the TD to fill the CC with a contrast agent in 16 human cadavers. Both magnetic resonance lymphography (MRI) and computed tomography (CT) studies could be performed on the same anatomical specimen, using a contrast medium which hardened, allowing gross dissection. MRI and CT detectability were evaluated, and imaging results were compared with the anatomical dissection. The CC of 12/16 cadavers were successfully injected, and four were unsuccessful due to technical difficulties, showing the effectiveness of the method. This technique can improve understanding of the anatomy of the TD and CC and provides an original option to study the complex anatomy of these structures by correlating precise cadaveric dissections with cross-sectional imaging.

Laparoscopic ligation of cisterna chyli for refractory chylothorax: A case series and review of the literature

OBJECTIVES

We describe an alternative surgical technique for the treatment of chylothorax in patients who have had failure of or are not candidates for transthoracic ligation or embolization by interventional radiology.

METHODS

We describe our experience with laparoscopic ligation of the cisterna chyli in 3 such patients and compare our results with published literature. We used a 5-port approach as for foregut surgery. We retracted the liver, transected the gastrohepatic ligament, and retracted the stomach to the left. We exposed the right lateral aspect of the aorta at the level of the celiac trunk and clipped fatty tissue between the aorta and the right crus. We skeletonized the right crus and dissected from the right crus to the inferior vena cava. We then retracted the inferior vena cava laterally, exposed all soft tissue posteriorly, and identified the cisterna chyli posteromedially to the inferior vena cava. Finally, we ligated and clipped all fatty tissue between the right crus and the inferior vena cava.

RESULTS

Success rate was 67%; 1 patient with idiopathic chylothorax did not have resolution and eventually died of multisystem organ failure. There were no procedure-related complications.

CONCLUSIONS

Laparoscopic ligation of cisterna chyli is an available therapeutic option for patients with chylothorax unresponsive to medical management, embolization, and transthoracic ligation of the thoracic duct. Our series is comparable with other reports of transabdominal approach to chylothorax.

Management of Chyle Leak after Head and Neck Surgery: Review of Current Treatment Strategies

Chyle leak formation is an uncommon but serious sequela of head and neck surgery when the thoracic duct is inadvertently injured, particularly with the resection of malignancy low in the neck. The thoracic duct is the primary structure that returns lymph and chyle from the entire left and right lower half of the body. Chyle extravasation can result in delayed wound healing, dehydration, malnutrition, electrolyte disturbances, and immunosuppression. Prompt identification and treatment of a chyle leak are essential for optimal surgical outcome. In this article we will review the current treatment options for iatrogenic cervical chyle leaks.

The thoracic duct: clinical importance, anatomic variation, imaging, and embolization

The thoracic duct is the body's largest lymphatic conduit, draining upwards of 75 % of lymphatic fluid and extending from the cisterna chyli to the left jugulovenous angle. While a typical course has been described, it is estimated that it is present in only 40-60% of patients, often complicating already challenging interventional procedures. The lengthy course predisposes the thoracic duct to injury from a variety of iatrogenic disruptions, as well as spontaneous benign and malignant lymphatic obstructions and idiopathic causes. Disruption of the thoracic duct frequently results in chylothoraces, which subsequently cause an immunocompromised state, contribute to nutritional depletion, and impair respiratory function. Although conservative dietary treatments exist, the majority of thoracic duct disruptions require embolization in the interventional suite. This article provides a comprehensive review of the clinical importance of the thoracic duct, relevant anatomic variants, imaging, and embolization techniques for both diagnostic and interventional radiologists as well as for the general medical practitioner.

KEY POINTS

• Describe clinical importance, embryologic origin, and typical course of the thoracic duct. • Depict common/lesser-known thoracic duct anatomic variants and discuss their clinical significance. • Outline the common causes of thoracic duct injury and indications for embolization. • Review the thoracic duct embolization procedure including both pedal and intranodal approaches. • Present and illustrate the success rates and complications associated with the procedure.

The changing management of chylothorax in the modern era

Initial conservative therapy is applied to all cases of chylothorax (CTx) with expected excellent outcomes. The indication for aggressive surgical treatment of early CTx remains uncertain and requires rigorous scientific scrutiny. Lymphangiography and lymphoscintigraphy are useful to localize the leak and assess thoracic duct patency as well as to differentiate partial from complete thoracic duct transection. The aetiology of the CTx, flow rate and patient condition dictate the preferred management. Octreotide/somatostatin and etilefrine therapy is highly efficacious in the conservative management of CTx. For patients in whom conservative management fails, those who are good surgical candidates, and those in whom the site of the leak is well identified, surgical repair and/or ligation using minimally invasive techniques is highly successful with limited adverse outcomes. Similarly, if the site of the chylous effusion cannot be well visualized, a thoracic duct ligation via video-assisted thoracic surgery is the gold standard approach. A pleuroperitoneal or less often a pleurovenous shunt is a final option and may be curative in some patients.

Chylous ascites after hepatopancreatobiliary surgery

Background

Postoperative chylous ascites following abdominal surgery is uncommon. It potentially induces malnutrition and immunodeficiency, contributing to increased mortality. In the field of hepatopancreatobiliary (HPB) surgery, no large studies have been conducted that focused on postoperative chylous ascites. The aim of this study was to determine the incidence, risk factors and management of chylous ascites following HPB surgery, with particular emphasis on pancreatic resection.

Methods

Consecutive patients who had HPB surgery between 2000 and 2011 at a single institution were reviewed retrospectively. Chyle leak was defined as 100 ml/day or more of milky, amylase-free peritoneal fluid with a triglyceride concentration of 110 mg/dl or above. Risk factors for chylous ascites associated with pancreatic resection and the clinical efficacy of octreotide in treating chylous ascites were evaluated.

Results

Of 2002 consecutive patients who underwent HPB surgery during the study period, 21 (1·0 per cent) developed chylous ascites. Chylous ascites occurred relatively frequently in patients who had a pancreatic resection, such as pancreaticoduodenectomy (3·3 per cent) or distal pancreatectomy (3·8 per cent). Multivariable analysis revealed that manipulation of the para-aortic area (P &lt; 0·001), retroperitoneal invasion (P = 0·031) and early enteral feeding after operation (P &lt; 0·001) were independent risk factors for chylous ascites following pancreatic resection. Octreotide treatment decreased drainage output of chylous ascites on day 1 after initiation of treatment (P = 0·002).

Conclusion

Chylous ascites is a rare complication following HPB surgery. It is more common after pancreatic resection. Treatment with octreotide combined with total parenteral nutrition is recommended.

Thoracic duct embolization for chylous leaks

Chylous leaks, such as chylothorax and chylopericardium, are uncommon effusions resulting from the leakage of intestinal lymphatic fluid from the thoracic duct (TD) and its tributaries, or intestinal lymphatic ducts. The cause can be either traumatic (thoracic surgery) or nontraumatic (idiopathic, malignancy). Treatment has traditionally consisted of dietary modification (nonfat diet) and/or surgery (TD ligation, pleurodesis). Thoracic duct embolization (TDE) has become a viable treatment alternative due to it high success rate and minimal complications. In this article, the authors describe the etiologies of chylothorax, patient population, outcomes, and long-term follow-up of TDE patients. Relevant lymphatic anatomy and physiology are reviewed, with special attention paid to the formation of the duct by tributaries at the cisterna chyli (CC). The technique of TDE is outlined, including bilateral pedal lymphangiography, TD cannulation, and embolic agents used for the procedure.

Laparoscopic management of chyle leak after Nissen fundoplication

A 41-year-old man presented with chylous ascites 6 weeks after a laparoscopic Nissen fundoplication. The chyle leak was successfully treated with laparoscopic ligation of the leaking duct at the right crus. We would now recommend early consideration of this as a treatment option for this rare complication.

Postural effect on the size of the cisterna chyli

BACKGROUND

The aim was to investigate the effect of patient position on the size of the cisterna chyli using positional MRI. The cisterna chyli is usually the only large lymphatic vessel that can be found on cross-sectional imaging. Not much is known about its postural behavior. However, animal studies suggest that the cisterna chyli varies in size according to physical activity.

METHODS AND RESULTS

Retrospectively, 998 MRI scans of patients referred for positional MRI were reviewed. Ten patients had acquired axial scans in at least two positions at the level T12/L1 or/and L1/2 and were included in the study. The area representing the cisterna chyli was assessed on axial images and its size was compared in different positions. The size of the cisterna chyli determined as the cross-sectional area was 14.7 mm² ± 17.3 mm² in the supine position, 43.8 mm² ± 3.1 mm² in the sitting position, and 62.9 mm² ± 42.5 mm² in the standing position. Using the t-test, a statistically significant difference was found in the size of the cistern chyli between supine and standing positions and between supine and sitting positions.

CONCLUSIONS

The size of the cisterna chyli shows postural variations. This finding is discussed in regards to possible implications of interventional procedures in the thoracic duct. Physicians reading MR images acquired in positions other than supine should be aware of these physiological changes.

Reliability of Poirier's triangle in localizing the thoracic duct in the thorax

PURPOSE

Preemptive ligation of the thoracic duct (TD) is occasionally performed during cardiothoracic procedures to prevent chylothorax. Landmarks for localizing this structure are thus important to the surgeon during such procedures. One historically used area for identifying this structure in the thorax is Poirier's triangle. The present paper aimed to investigate the relationship of the TD to Poirier's triangle.

METHODS

We evaluated the use of this geometric area in localizing the TD in 35 adult cadavers.

RESULTS

Poirier's triangle was found in all specimens, but the TD was found within the confines of Poirier's triangle in only 17 specimens (45.7%). When not identified in Poirier's triangle, the regional TD was often (28.6%) seen in the interval between the proximal left subclavian and left common carotid arteries.

CONCLUSIONS

These data may be of use to the surgeon when identifying the proximal TD within the thorax.

Cisterna chyli in patients with malignancy--influence of cardiovascular disease on the prevalence of the cisterna

The purpose of this study was to investigate the potential correlation between the presence and size of the cisterna chyli (CC) on computed tomography (CT) and the presence of cardiovascular disease.

MATERIALS AND METHODS

Out of a 3000-patient cohort 2599 patients who received a CT examination of the chest and/or abdomen with measurable inferior vena cava and azygos vein were included in this retrospective study. To assess the presence of cardiovascular disease the following parameters were recorded from the PACS or clinical information system: diameter of vena cava and azygos vein, presence of ascitis, serum creatinine, history of congestive heart failure, coronary artery disease or arterial hypertension and medication (diuretics, beta-blocker). In addition the volume of the CC and the presence or absence of malignant disease were recorded. Mean values (vessel diameters, creatinine) or percentages were calculated and compared for the groups with (n=416) and without (n=2183) a cisterna. Multivariate logistic regression analysis was performed for all parameters to identify the potential association with the presence and size of a cisterna. In addition the simultaneous influence of the parameter malignancy, cardiovascular disease and age on presence and size of the CC was analyzed in a logistic regression model.

RESULTS

The presence or absence of a CC was not associated with any of the measured parameter. Regarding the size of the CC, there was a positive correlation with the diameter of the azygos vein, the presence of ascitis and diuretic medication. The influences of malignancy, elevated central venous pressure and age on the development of a CC proved to be highly significant but could not be separated or quantified.

CONCLUSION

The volume of the cisterna chyli is influenced by pathologic states with an increased central venous pressure, while the presence or absence of the cisterna seems to be independent of those factors.

Cisterna chyli in patients with malignancy--is there a correlation between changes in cisterna volume and progression or regression of the tumor?

The purpose of this study was to investigate the potential correlation between the size of the cisterna chyli (CC) and the tumor size in patients with malignancies on computed tomography (CT).

MATERIALS AND METHODS

Out of a 3000 patient cohort 138 patients with histologically confirmed malignant disease, a detectable CC on CT and at least two CT scans within a 6 month period were included in this retrospective study. Out of 525 scans a total of 711 lesion intervals were evaluated. The volume of the CC and all target lesions (up to three per scan) were recorded. The Pearson correlation coefficient for the two parameters of changes in lesion size and CC size was calculated for the whole cohort and for a 33 patient subgroup that included only patients with tumors that showed the closest association with large CC in a previous study.

RESULTS

The mean difference in lesion size for all 711 intervals was -1165μl. The mean difference in CC size for all 711 intervals was -46.6μl. The respective Pearson correlation coefficient was .05 with a non-significant p-value of .1823 (subgroup: r=.04, p=.6358).

CONCLUSION

No significant correlation between the progression or regression of malignant disease and the size of the cisterna chyli could be found.